research Magazine of the Deutsche Forschungsgemeinschaft german

SPECIAL 2004 Peep into a Different World How a Town Can be Created in a Test Tube Afghanistan: The Culture of the Kafirs In the Service of the Crown When Plants Tell of Their Environment german research SPECIAL 2004

In this issue Content

...an Investment Expedition to the Volcanoes When Merapi in the Future ...... p. 2 of the Arctic Seafloor . . . p. 44 Spits Fire A Rose is When Plants Tell a Rose is a Rose? ...... p. 4 of Their Environment . . . p. 50 Of the 129 active volcanoes to be found in Indonesia, Merapi, On the Trail Peep into a 2,691 metres in elevation, is of Glowing Lava Flows . . . p. 8 Different World ...... p. 55 the most restless. Over the past 450 years it has erupted every Life and Death On the Battlefield seven years on average. The in Ancient Egypt ...... p. 14 of Chiapas ...... p. 59 local population is relying on scientists to improve their Travel Educates – The Refuge chances of survival after an Clichés Persist ...... p. 20 under the Bark ...... p. 62 eruption. Page 8 A Treasury in Sibiria . . . . p. 66 Ornamental Gothic Vaults from Computer . . . p. 24 The Loneliness Life and Death of Island Life ...... p. 73 in Ancient Egypt In the Cockpit of the Fly ...... p. 28 In the Service Modern Egyptologists can of the Crown ...... p. 76 read the mortal remains of Afghanistan: mummified corpses of ancient The Culture of How a Town Can be Egyptians buried three and a the Kafirs ...... p. 32 Created in a Test Tube . . . p. 80 half millenia ago like medical case histories, enabling far- A Climatic Archive The Deutsche reaching conclusions to be with Hide and Hair . . . . . p. 37 Forschungsgemeinschaft p. 84 drawn regarding their con- temporary society and its “health system”. Page 14 Innovations for the Microscopic World Microsystem technology can open up the way The Fly to new products in medicine, analysis and as a Model electronics. The aim is to combine microcom- ponents to form novel types of microsystem. Thanks to its large, facetted Researchers are investigating the fundamen- eyes, the fly enjoys almost com- tal concepts for this. pletely all-round vision. This (Cover photo: IPT-Aachen) makes it possible for it to per- form its breath-taking flight manoeuvres. Using a panorama Impressum cinema, “FliMax”, scientists in- “german research SPECIAL 2004” is a special edition of the DFG’s newsmagazine vestigated how the sequential “german research”, which appears three times per year. “german research” is pub- images received in the fly’s lished by the Deutsche Forschungsgemeinschaft (DFG, German Research Founda- headlong flight are processed in tion); Editorial staff: Dieter Hüsken (editor-in-chief, design), Dr. Rembert Unterstell, Ursula Borcherdt-Allmendinger, Angela Kügler-Seifert (coordinator); English con- its brain. This method enables sultant: Nicholas Naughton BDÜ; Publisher: Wiley-VCH Verlag GmbH & Co. KGaA, biologists to gain important in- Weinheim, P. O. Box 10 11 61, 69451 Weinheim (Germany); Annual subscription sights into the neuronal proces- rates 2004: € 44.00 (Europe), US $ 48.00 (all other countries) including postage and handling charges. Prices are exclusive of VAT and subject to change. ses and mechanisms of image Printed by: Bonner Universitäts-Buchdruckerei; Address of editorial staff: processing. Page 28 Deutsche Forschungsgemeinschaft, Press and Public Relations Division, Kennedyallee 40, 53175 Bonn (Germany); E-mail: [email protected]; Internet: www.dfg.de; printed on chlorine-free bleached paper with 50 % recycling fibres. ISSN 0172-1526

german research SPECIAL 2004 Commentary

n today’s world, science is in- collaboration offers particularly young investigators from all over creasingly dependent on the col- favourable conditions for the inter- the world the opportunity to work Ilaboration of researchers, on the national training and mobility of re- in one of the participating Euro- joining of minds and resources searchers. pean countries for a five-year peri- across disciplinary, national and The highly dynamic develop- od as leaders of independent junior cultural boundaries. Since its incep- ments in Europe bring about new research groups. tion, the Deutsche Forschungsge- challenges and opportunities for meinschaft (DFG, German Research research and research funding. Foundation) has been committed to The DFG is firmly committed to n order to intensify international fostering and facilitating the inter- contributing to the realisation of a cooperation and networking, the national cooperation of researchers. European Research Area and to IDFG has established representa- A large and growing number of re- collaborating with European part- tions in selected regions of the search projects in Germany is con- ner organisations on initiatives de- world which are of particular signi- ducted in collaboration with part- signed to enhance the funding of ficance for present and future col- ners from other countries. Many of cross-border activities, support the laboration. The Sino-German Cen- these projects – for instance in the mobility of researchers, and create ter for Science Promotion, which is fields of earth and environmental joint funding schemes. A recent ex- operated jointly by the DFG and the sciences – are integrated into inter- ample for these efforts is the estab- National Natural Science Founda- national programmes coordinated lishment of the European Young tion of China, was opened in Beijing at European and global levels. In- Investigator Award (EURYI) pro- in 2000. The DFG has recently es- ternational cooperation is thus a gramme which is funded jointly tablished liaison offices in Washing- necessary and increasingly impor- by 18 national research organisa- ton, D.C., and in Moscow. tant component of research funding tions from 14 European countries. The United States continues to be and is, in fact, one of the DFG’s This programme offers outstanding a particularly attractive country for strategic priorities. Cooperation with international partners is encouraged in all of the DFG’s funding programmes, begin- ning with the support of young re- searchers. Of the nearly one thou- sand fellowships awarded every Prof. Ernst-Ludwig Winnacker year by the DFG to young postdoc- toral scientists more than two-thirds are used to fund research stays International cooperation is becoming abroad. The United States of Amer- ica hosts the majority of these fel- an increasingly important part of science lows. The personal experience gained and contacts made as a re- and research. Therefore, the DFG is committed sult of these visits form a basis for to fostering collaboration and exchange between future cooperation. Another exam- ple illustrating the international di- German researchers and partners across the globe. mensions of the DFG’s programme Enabling scientists to work together across portfolio are the Research Training Groups. In these university training disciplinary and national boundaries helps tackle programmes doctoral students pur- sue their degree within the frame- the world’s major scientific questions and is thus... work of a coordinated research and study programme run by a team of university teachers. So far, 28 Inter- national Research Training Groups – a variant of the traditional pro- gramme – have been established ...an Investm between German universities and universities in other countries. The research and study programmes are developed and supervised jointly and provide the participat- in ing students with the opportunity for research stays at their respective partner universities. The frame- 2 work of such “centre-to-centre”

german research SPECIAL 2004 German researchers. One of the main tasks of the DFG Washington Office therefore is to support the nu- merous DFG fellows in the US, both with regard to their return to Ger- many and to opportunities for transatlantic cooperation. In addi- tion, the office is dedicated to ex- panding cooperation with our part- ner organisations in the US, and providing information for American scientists and research institutions about opportunities for collabora- tion with partners in Germany. Sev- eral joint activities have been initi- ated in recent years. Among them are the Arabidopsis Functional Ge- nomics Network initiative, which was implemented in close coopera- tion between the DFG and the Na- tional Science Foundation. Other examples include joint funding activities in the areas of digital libraries and materials science, pro- gramme networking in education research, as well as the establish- ment of a Transregional Collabora- tive Research Centre on process chains for the replication of optical elements, a cooperative effort of re- searchers from the universities of Bremen and Aachen and Oklahoma State University at Stillwater.

n April 2004, the first DFG Re- search Conference will be held in IWashington, D.C., in the field of geosciences. It will be co-sponsored by several partner organisations in the United States and is designed to bring together young researchers from both sides of the Atlantic and serve as a forum for developing joint research activities. Enabling international coopera- tion in research is an investment in the future, and the DFG will contin- ue to foster collaboration and ex- change between the German re- search community and partners ent across the globe. the Future Ernst-Ludwig Winnacker President of the Deutsche Forschungsgemeinschaft 3

german research SPECIAL 2004 A Rose

4 Life Sciences is a Rose is a Rose?

What everyone has always wanted to know about the sexuality of roses: study of their reproduction is primarily of benefit to plant breeders

here is scarcely any plant that inside the body of the plant. He had has so inspired the imagination also noticed the different form of the Tand cultural history of man- sepals on many roses, a feature kind as the rose. As the symbol of which is still used today to distin- love and innocence it has acquired guish the group of the Dog Roses the role of “queen of the flowers”. from all the other roses. However, For the plant taxonomist, howev- the scientific study of roses, rhodolo- er, it presents a totally different pic- gy, dates from the beginning of the ture. Of the nearly 200 species of 16th century. It was at this period rose in the world, the group of the that, in the wake of the botanical Re- Dog Roses, the section Caninae, naissance, the first scientific herbals comprising some 30 species, are re- made their appearance. These garded by botanical taxonomists as books distinguish in essence be- critical plants. Although the majori- tween only two groups: the “tame”, ty of the problems involved are at- meaning the double, cultivated tributable to the specific biological, blooming roses, and the “wild” and primarily genetic, characteris- ones, the single, wild roses; both tics of Dog Roses, there nevertheless groups in their individual white and remains a significant portion of red colour variations. Up to the end problems in this group which arise of the 16th century, the “inventory of from their history. species” in these herbals continued The theologist and naturalist to expand, partly through the intro- Albertus Magnus (ca. 1200 to 1280) duction of new roses from other was already able to distinguish areas. One of the last herbals of this between the thorns of a rose, which epoch was compiled by John Gerad grow on the bark, and the thorns of in 1597. His “Herball“ already con- other plants, which spring from tained 16 different roses, and marks 5

german research SPECIAL 2004 the beginning of the parting of the Around 1930, some 2,000 names of somes; in the case of the Dog Roses, ways between scientific and horti- different taxonomic ranks for roses there are normally five sets of chro- culturally orientated rhodology. were in existence. In 1931, the Swiss mosomes. However, the formation The following centuries saw near botanist Robert Keller co-ordinated of the sex cells, the gametes, does stagnation in the progress of rhodol- and evaluated this abundance of not generate cells with an identical ogy. However, as the 19th century published names, using morpholo- number of chromosomes, as the egg dawned, interest in roses exploded gical criteria to extract those species cell retains four sets of chromo- and led to an incredible abundance for Central Eu- somes, while the of literature, which today encom- rope, approxi- fertile pollen passes around 6,000 titles. The mately 30 in Mistaken understanding grains only con- growing knowledge of new species number, which of the reproductive pro- tain one chromo- and forms in the family demanded a are still accepted some set. This more comprehensive principle of today. Finally, in cesses of roses led to the mode of unequal classification. The start was marked 1940, the most discovery of a flood distribution is in 1818 by a publication by the popular compre- called “hetero- botanist Pyramus Auguste de Can- hensive system of new “species” gamy”. On fertil- dolle. Using morphological charac- was developed isation, the origi- teristics as a basis, he divided the as a synthesis of nal five-fold family into a total of eleven sections. the numerous precursor systems. In (pentaploid) state is restored, with The 19th and early 20th centuries saw this, nearly 200 species are listed the result that progeny from hybrids the Golden Age of rhodology. world-wide, and the genus is sub- bear a greater similarity to the divided on the basis of specific mor- mother plant, as she provides 4/5 of phological characteristics into four the genotype (namely, four out of Controversy long reigned over the mode of reproduction in Dog Roses. Today, we sub-genera and ten sections. five sets of chromosomes). th know that they normally have a sexual Early in the 20 century, the The discovery of this so-called relationship in which the barriers to hybri- Swedish botanist Gunnar Täckholm “Canina meiosis” raised two imme- disation between the various species are discovered that the group of the Dog diate questions: what had caused only weakly marked. Roses are largely polli- Roses – the dominant section of the the appearance of such a form of re- nated by insects, although the open flower roses in Central Europe – is charac- production and this internal genetic is also amenable to wind pollination. Right: terised by a unique mode of sex cell structure of the Dog Roses, and Molecular research clearly identified the “Soft-Downy rose” as the mother of a formation. All Dog Roses are poly- were organisms with such a remark- natural hybrid. The other parent originated ploid, which means that they con- able genetic system in any way ca- from the Asiatic Japanese rose. tain more than two sets of chromo- pable of sexual reproduction, or did this happen simply through apomix- is, i.e. seed formation without fertili- sation? Despite the fact that scien- tists had been able to describe the sexual reproduction of the roses as long ago as in the years 1908 to 1915, Täckholm believed in apomic- tic reproduction within the group. Logically, then, each individual rose bush and its progeny, having its own fate in evolution, and not par- ticipating in any genetic exchange with other individuals in the group, ought to be regarded as a “species” in itself. This led to the view that each morphological change, no matter how small, characterised a new species and had thus earned a new name, which added consider- ably to the flood of names men- tioned above. Even today, we are not completely able to explain the biology of dog-rose reproduction, even though as preparation for this research project nearly 500 hybridi- sation experiments were conducted amongst wild populations, and the 6 results published in 1997. As far as is known today, Dog Roses reproduce almost exclusively sexually, with scarcely any barriers to hybridisation between the indi- vidual species. Self-pollination is also successful, and also seed for- mation without fertilisation, in other words, the apomictic reproduction mentioned above. With a view to answering the questions regarding the causes of the appearance and origins

of this type of meiosis repro- duction and genetic consti- tution, a genetic analysis, so-called sequencing, was conducted on a section in the genome entity of the plants. For the first time, working at the as resistance to frost molecular level, we succeeded in and disease, into special detecting hybridisation both in arti- breeding programmes. Apart ficial and natural hybrid roses. A from their relevance for hybrid is an individual produced as the Dog Roses. This confirms the basic research, and espe- a cross between two genetically thesis postulated by Robert Keller cially for taxonomic botany, the different parents. This process is back in 1904, that Rosa jundzillii is a results of this study are of great in- known as hybridisation. hybrid between Rosa gallica and a terest to plant breeders. They can Our experiments revealed that all representative of the Dog Roses. in the long term lead to new the roses of the Caninae section This project furnished the first- breeds of enormous economic sig- which we examined were so-called ever identification of the permanent nificance, and thus reforge the permanent hybrids. Thus the Rosa hybridogenous constitution of the link between the two “horticultural” canina, the Dog Rose, contains four Dog Roses, and facilitated the initial and “scientific” lines in rhodology, different sets of chromosomes. At characterisation of the sets of chro- which were instituted by the “fa- the same time we were able to mosomes. This will, in principle, thers of botany” in the 16th century demonstrate that set A is not con- make it possible to explain the com- when they created the division into fined to the Dog Rose, but is also pre- plete phylogenesis of the group, en- tame and wild roses. sent in the Red (French) Rose, Rosa abling statements to be made on the gallica, which is a member of anoth- occurrence of, and justification for, Dr. Volker Wissemann er section, that of the Gallicanae. described “species”. Furthermore, Prof. Frank H. Hellwig Rosa gallica contains, in addition, a the selective characterisation of indi- Universität Jena B set, which we were finally able to vidual genome elements will permit Prof. Fred-Günter Schroeder identify again in Rosa jundzillii the integration of the Dog Roses and Prof. Gerhard Wagenitz (Rough-leafed Rose), a member of their valuable characteristics, such Universität Göttingen 7

german research SPECIAL 2004 For the local population Merapi is the “fiery mountain”. To improve their chances of survivalafter an eruption, they are trusting in a reliable early warning system Natural Sciences On the Trail of Glowing Lava Flows

Merapi, 2,961 metres high, rises out of the clouds like the battlements of some enchanted fairy-tale castle. It is the most restless of the 129 active volcanoes in Indonesia. In the past 450 years it has erupted every seven years on average. n 22 November 1994 a large part of the viscous blocks of Olava which had accumulated on the summit of the volcano Mer- api started to slip. Two million cubic metres of rock cascaded into the valley. The flow of detritus was ac- companied by explosions and clouds of ashes with temperatures ranging up to 700° C. A village at the foot of the volcano was de- stroyed, 66 people died, many hun- dreds suffered third-degree burns. In the days before, the seismometer stations of the Volcanological Sur- vey in Indonesia had registered slight, but not abnormal, activity in the volcano. Scientists and the local populace were equally surprised by the eruption and by the fact that the glowing avalanches of lava flowed to the south, and not, as in previous years, to the south-west. Merapi (lit. “fiery mountain”), 2,961 metres high, lies in central Java and is the most restless of In- donesia’s 129 active volcanoes. In the past 450 years it has erupted every seven years on average. The fact that it is located in the zone where the Eurasian and Indo-Aus- tralian plates collide means that Merapi is classed as an explosive volcano. This type is found every- where where the rigid plates form- ing the outer skin of the earth are forced on top of each other. On so- called “subduction” into the hot mantle, the dipping plate and its wedge of mantle become partially molten. The melts then begin to rise. On their way up their chemical com- position alters until the magmas reach the earth’s surface in an erup- tion. Should the gush of viscous lava and the unimpeded escape of gases be prevented, then the pressure in- side the volcano will rise until, final- ly, parts of the edifice of the volcano are blown off in an explosion. Three of the world’s five greatest explo- sive eruptions of the last two hun- dred years have taken place in south-east Asia: the disastrous eruptions of Tambora (1815), Krakatau (1883), and Pinatubo (1991). Apart from any local de- struction, volcanic eruptions of this magnitude affect the global climate, giving rise in former times to disas- 10 trous famines.

german research SPECIAL 2004 Merapi was also largely de- on average once a year. Due to the stroyed at some time in the past by a dense settlement at the foot of the major explosion which took a south- volcano and the farming of its westerly direction. The greatest flanks, even minor volcanic events eruption in recorded history oc- can present a threat. curred in 1872. This was a highly Systematic monitoring of Merapi explosive eruption accompanied by began back in the thirties of the 20th the formation of a high eruption col- century. The Dutch colonial govern- ment of that time built five observa- tion stations on the flanks of the vol- Measuring the temperature at Merapi´s cano. These were equipped with a summit. The composition and temperature seismograph, meteorological sen- of the rising gases furnish information sors and, in more recent times, sen- on the state of activity of the volcano. sors for determining the sulphur Below left: A seismometer in process of dioxide content of the volcanic gas installation. Every article of equipment has to be laboriously transported up the cloud. The crucial element of this slopes to the metering stations by monitoring system, however, were porters. observers maintaining round-the-

umn. Subsequent to this, the pre- clock observation of the volcano’s vailing eruptive mechanism under- activities and reporting each went a change. Today, Merapi very change – as they are still doing gradually forms a dome, a tumefac- today. Since the early eighties, the tion of loosley stacked, partially observation network has been ex- consolidated, boulders of lava, tended in co-operation with re- which then suddenly begins to slip. search groups from Germany, Incandescent lava starts to flow at France, the USA and Japan. speeds of over 100 km/h into the Since mid-1994, the Geo- valley. 32 of the 67 documented his- ForschungsZentrum Potsdam (GFZ) torical eruptions of Merapi have has been building a ground obser- been accompanied by pyroclastic vatory, which has enjoyed DFG sup- flows – a frequency unique amongst port since 1997. A total of 18 univer- the world’s volcanoes. At the pre- sities and geoscientific institutes in sent time, this phenomenon occurs Indonesia and Germany are partici- 11

german research SPECIAL 2004 12 On 17th January a mighty cloud rose high into the air as Merapi erupted. Despite its threatening aspect it did not cause any damage. At the present phase of activity of the volcano such explosive eruptions are the exception. Right: Scientists have erected a tented camp on the slopes of the volcano Merapi.

pating in the MERAPI (Mechanism Evaluation, Risk Assessment, Pre- diction Improvement) project, which aims to improve our under- standing of volcanological process- es, and our ability to evaluate threats and predict volcanic erup- tions in the short and medium terms. A dense network of metering sta- tions is continually recording the parameters relevant to volcanic ac- tivities. The data are transmitted by radio to the central office in Jog- jakarta. The vital parameters of a volcano’s activity are volcanic earthquakes, deformations of the volcano’s edifice, and changes in the gases it expels. Improved under- standing of the processes inside the volcano will enable future eruptions summit. This world “first” was eruptions. Hence, the experiments to be predicted more exactly and re- achieved through a gas chromato- are now to be increasingly integrat- liably than hitherto, but only if we graph especially adapted to rough ed into the local early warning sys- have precise knowledge of the conditions. tem. Early warning has so far been sources of the metered signals, and One elementary part of the pro- based essentially on the time lag be- if distortions, and especially those ject are geological studies of the tween the beginning of an eruption due to the weather, can be eliminat- magma development and the erup- and its arrival in the inhabited ed from the data. tive history of areas. The peo- Merapi. At some ple have up to ne of the best known seismic point in the past, The people are eight minutes to phenomena associated with Merapi suffered less interested in the reach their shel- Ovolcanoes are prolonged reg- vast damage ters or to move to ular vibrations, also known as from a disastrous mechanism of Merapi safe areas. Each “tremors”. Controversy still reigns eruption. Until than in predicting extension of this over their origin; the most likely recently, and re- time, maybe for cause are oscillations of the magma lying on histori- eruptions erecting barriers column in the passages and vents of cal sources, this or for early evac- the volcano, similar to the noises in eruption had uation, can save the pipes of heating systems. Anoth- been dated to 1006, and had been lives. As the flanks of the volcano, er type are tremors with very com- associated with the demise of the however, are not only a lethal plex seismograms, which are briefly once flourishing Hindu culture in threat, but also, and primarily, the identifiable as very flat earthquakes central Java. Dating by the carbon life-blood of the peasants, such in- directly under Merapi’s summit. isotope C14, however, indicates that structions will only be complied They must almost certainly be it took place much earlier. Accord- with if the predictions are held to be linked to the growth of the lava ing to this, the greatest known erup- soundly based. dome, and are possibly generated tion occurred 6,000 years ago or by tearing of the brittle outer skin of more. The results obtained so far are Prof. Jochen Zschau the dome. Last year, for the first a step towards improved under- Dr. Malte Westerhaus time, scientists succeeded in moni- standing of Merapi. The local popu- Birger-Gottfried Lühr toring the composition and temper- lace, however, are less interested in GeoForschungsZentrum ature of the fumarolic gases at the its mechanism, than in predicting Potsdam 13

german research SPECIAL 2004 Life Sciences

Life and Death in Ancient Egypt Modern Egyptologists can read the mortal remains of mummified corpses of Egyptians buried three and a half millennia ago like medical case histories, enabling far-reaching conclusions to be drawn regarding their society and its “health system”

14 The tomb of Pharaoh Ramses IV in the Valley of the Kings. Despite plundering and partial destruction of the great necropolises, researchers can still uncover well preserved finds, such as the mummified torso shown here. A broken clavicle, which had later healed, was evidently the result of degenerative attrition of the epiphysis (left, alongside, a normal clavicle).

15 16 urrent knowledge of the life led by ancient populations Cstems largely from archaeo- logical studies, and especially from the analysis of scripts, graphic rep- resentations and the remains of buildings and other constructions. These activities furnish indirect in- formation on the living conditions and customs native to ancient cul- tures which – depending on the spirit of the age and interpretation – can give rise to considerable conjec- ture. The precise extent to which they do in fact reflect the conditions of life must remain an open ques- tion. A much more direct insight can be obtained from examining human remains, as these reveal the physi- cal disorders and other suffering with which these witnesses to the past were confronted. In the majori- ty of cases, these remains consist of bones and teeth, which are compar- The “Necropolis of the Scribes and atively immune to deterioration Scholars” is cut into a rocky ridge in over prolonged periods of time. Thebes West in Upper Egypt. This mummy of a man aged around 35 exhibits osseous Researchers into ancient peoples changes of the lower lumbar vertebral whose dead have become mummi- column with partial destruction of the fied through natural causes (hot- anterior face. The computer tomographic arid climate) or by artificial methods examination reveals the bone destruction (embalming) have an especially caused by an inflammation. Above: The easy task. In these cases, many of disintegration of the skull of this 35- to the remains will contain internal or- 40-year-old woman indicates a malignant tumour. The body of a man aged 20 to 25 gans and soft-part tissue which can (small illustration, left) also exhibited in individual cases furnish far- bone probably destroyed by a reaching information, for example, metastasising tumour. through analysis of still detectable biomolecules. Thus we can thank the religious beliefs of the ancient Egyptians that we now have well the capital of the Egyptian empire. preserved human The location of the burial grounds remains dating examined revealed that they were back to around predominantly occupied by mem- 5,000 years ago. bers of the upper social strata, who Since 1966, an were presumably well provided for. interdisciplinary Hence it has been widely assumed team from Mu- that the incidence of cancer would nich University have been relatively low, although has been examin- very few concrete studies have ing the human re- been conducted on this topic to mains in the great date. The interdisciplinary ap- necropolis of proach is vital, as interpretation of Thebes West, in the data can often only be made in Upper Egypt, in the context of the Egyptological ob- order to discover servations at the site of the find, the the composition and way of life of dating of the finds, and associated its inhabitants during that period, data on the social environment of and the prevalence of specific dis- the individuals interred there. In in- eases. During the “New Kingdom” dividual cases this analysis can go (from ca. 1500 B.C.), Thebes was so far as to identify historical per- 17

german research SPECIAL 2004 sonages and important aspects of left their marks. The remains often their lives. consist of mere fragments of bone The biomedical studies embrace tissue. As a result, most medical detailed, on-the-spot, recording of finds relate solely to diseases which every conspicuous find; this is sup- manifest themselves in the bones plemented by endoscopic examina- and joints. tion, especially of The remains of internal skull over 400 individ- cavities, and by The mean age at death uals have so far x-rays and com- of the population under been examined puter tomo- in three major graphs of select- study showed a maximum burial grounds in ed artefacts. Fur- at between 20 and 30 Thebes West, of thermore, molec- which children ular biological years of age and adolescents, examinations fur- with 90 individ- nish supplemen- uals, made up tary information regarding specific around 22 per cent of the total. The diseases. Despite the fact that the mortality rate for children was desert climate contributes greatly to found to be very low when mea- the preservation of the dead, time, sured against that in modern Egypt and interventions by grave plunder- at the turn of the present century, ers and predatory animals have also which lay at around 60 per cent! One must, however, remember that there could have been special chil- dren’s cemeteries and children’s 100 years ago, examining mummies was burials within the settlements. The a “social event” and lacked any great mean age at death of the population scientific value. The externally intact under study showed a maximum at head of this mummified man (small between 20 and 30 years of age, illustration, above, right,) raises no with a peak at around 40; in other suspicions of a severe trauma due to a blow to the head. Only the computer words, a comparatively low life ex- tomograph revealed a gaping wound pectancy for the inhabitants of a above the parietal bone – a trauma he capital city sporting a populace did not survive for long. Below: Lack of whose needs were adequately pro- bone substance (osteopaenia) is often vided for. It is presumed that the dis- found in Theban mummies (above, a tribution of the age of death for the normal, below, an affected, bone). highest social stratum in ancient One cause could have been chronic vitamin D deficiency. Egypt, the Pharaohs, was also simi- lar, as has been suggested by earlier examinations of the mummies of kings now housed in the Cairo Mu- seum. Studies suggest that this could be attributable to a broad range of infectious diseases. The number of finds involving physical disorders of the most diverse kinds was exceptionally high. Thus many old bone fractures have been found where the victim had at least sur- vived the injury. Furthermore, the effects of caries have been identi- fied, whose diffusion had been pro- moted by marked abrasion of the teeth – a feature which was presum- ably attributable to sand in the food. Surprisingly often finds reveal os- seus changes indicative of chronic anaemia, dyshaematopoiesis (disor- ders affecting the formation of the 18 blood), and vitamin C and D defi- ciency – numerous indications that the general state of health was poor. Attrition of the joints (arthrosis) and degenerative changes of the spinal column are evidence of chronic stressing and straining of the joints from considerable physical loads. The discovery of malignant tu- mours, especially bone tumours, furnishes evidence not only of the fact that malignant tumours oc- curred in the contemporary popu- lace, but it also reveals that the fre- quency of such carcinomas was only a little less than it is today amongst people of the same age and sex spectrum.

ur studies also revealed indi- vidual cases of social care, Onursing and medical treat- ment of the sick. For example, the skull of an elderly man exhibited the results of a severe fracture of the middle part of his face. This man he had survived this injury for a long time afterwards. The fact that this individual could survive this mas- sive trauma for any length of time at all is indicative of special nursing care, for example, through the medium of a special diet. A further example of surgery is the skull of a mummy with a defect of the left parietal bone. The form and align- ment of the trauma are typical of a heavy blow. The fact that the skin and bandages are intact indicates that the bone fragments resulting from the injury had been removed “therapeutically”. In other words, this had been a surgical operation. In the course of this study of pathological changes, special tech- niques of molecular biology were employed to diagnose diseases which would have otherwise re- mained undiscovered. Thus we were able to detect the genotypes of certain bacteria which cause typical syndromes, and to employ molecu- lar evidence to detect the oldest known cases of tuberculosis. Tuber- culosis was evidently much more prevalent in ancient Egypt than has hitherto been supposed, and could be (co-)responsible for the low life expectancy of the ancient Egyp- tians. Prof. Andreas Nerlich Universität München 19 german research SPECIAL 2004 Arts and Humanities Travel Educates – Clichés Persist Do educational tours really broaden the mind? A study has revealed that they serve to entrench old clichés and prejudices

ourism in developing countries (Rabat, Meknès, Fez and Mar- embraces one form which is rakesh) and the South (Anti-Atlas, Tlauded for its extreme social Road of the Casbahs, and the oases compatibility, gentle impact on the of Drâa and Tafilalet). Further re- environment and even its impor- gions of the country, on the other tance for intercultural communica- hand, which would be either sceni- tion – educational travel. cally or culturally extremely re- It is a fact that educational travel warding, including the Rif, the is planned by reputable travel agen- Mediterranean coast, Beni Snassen, cies; it is very expensive and tours or places of economic importance are conducted by German (or, at such as Casablanca, Gharb, Phos- least, German-speaking) guides phate Plateau, Oujda, and Nador, who have specialised in the country are not on offer. The dominating concerned; the participants are themes are history and the presen- mostly middle class (teachers, self- tation of the special characteristics employed, pensioners); most of of natural regions of the country. them engage in intense preparation for their journeys, primarily by read- ing the guide-books. Morocco was selected as the country for an empirical study of the function of educational travel. This country in North Africa is consid- ered to be an attractive, many- faceted tourist destination. It forms part of the Islamic-oriental cultural sphere, and so instruction in various aspects of this different cultural background in the sense of achiev- ing closer contact, pleading for sym- pathetic understanding of an alien people, and even making an ap- proach to comprehending their cul- ture, becomes, in the ideal case, “enlightenment”. A survey of just under 500 educational tourists from Germany’s largest travel agency in this field was conducted in this sense prior to and on their return The fact that the visits made from their tours. on educational tours to The routes followed by the travel Morocco are almost exclusively agencies are similar and have re- confined to old cities and rural areas (our large photo shows mained almost unchanged for the casbah in Fez) decades. In Morocco, they are con- creates the impression 20 centrated on the four royal cities of a living museum.

german research SPECIAL 2004 21 Current social, economic and politi- cal aspects are neither offered in the travel catalogues, nor do they play any important role during the tour. Educational tours provide a very se- lective picture of the country con- cerned, and do not furnish any real- istic reflection of the current society. Guides tend to concentrate on tradi- tional, even archaic, but at the same time visually perceptible, elements with picturesque, exotic and aes- thetic features. People embarking on an educa- tional tour to Morocco harbour cer- tain expectations: they go because they expect a qualified guide, a high level of information and strict organisation. Especially in Moroc- co, they expect to see bizarre land- scapes (79 per cent), visit historic sites (72 per cent), acquaint them- selves with art and the trades (63 per cent) and feel the flair of the Ori- ent (60 per cent). Nevertheless, a third of them also hope to meet the people; half of them wish to experi- ence the desert; and a quarter of them wish to learn about Morocco as a developing country.

n the course of their preparations for the tour – and over 90 per cent Ido prepare themselves – 90 per cent of participants rely on guide- books; compared with these, all the other media and sources of informa- tion (TV programmes, conversa- tions with people who know Moroc- co, and regional literature) pale into insignificance. Thus these guide- books largely determine the extent of their prior knowledge of the country and the picture they form of it in their minds. The guide-books, the travel catalogues and the infor- mation imparted by their guide are The special knowledge students is less significant than they had sup- three stars which form a framework have acquired will be clearly en- posed. of perception and reference for the hanced as a result of their travels. Certain preconceived associa- tourist. The clichés also become modified in tions and ideas closely bound up Nevertheless, before the journey the course of the journey, but only to with Morocco will be reinforced: starts, their image of Morocco is a minor degree. Prejudices persist. “landscape”, “traditional rural soci- based not so much on any specific After their tour, the travellers no ety”, “poverty”, “oases”, “desert”, knowledge as on prejudices domi- longer consider Morocco a suitable “traditional and modern agricul- nated by such stereotypes as Islam, place for a seaside holiday, they find ture”, “traditional forms of housing” desert, exoticism and ideas about it more industrialised than they had and “elements of everyday life”. alien landscapes and people. Under thought, and also a democratic, sur- The fact that visits are largely con- these circumstances impartial ac- prisingly clean, country, with very fined to old towns and rural areas quaintanceship, discovery or gain- importunate inhabitants, where creates the impression of a living ing of experience is only possible to women have more rights than they museum. Associations with respect 22 a limited degree during the tour. had expected, and fundamentalism to “Orient”, “Islam” and “colonial

german research SPECIAL 2004 elements, the classical associations with the Orient tend to fade. A num- ber of pictures become confirmed in the minds of the tourists: “desert”, “developing country” and “bizarre landscapes”. Hence, in the course of an educa- tional tour clichés and prejudices al- ready held will be strengthened. Of course, these are augmented by fresh knowledge, but this is of only secondary significance compared with the emotional contents. As a result of the journey it is primarily those aspects which will be per- ceived and integrated into the exis- tent image of Morocco which do not demand any cultural rethinking, or even the making of any concessions to the alien culture. Consequently, the overall image is scarcely changed. The participants evidently only seek a dosed and controlled encounter with what is alien to them – an expectation which will be met in full by the travel agencies offer- ing these journeys.

hould anyone be expecting to find any high claim to emanci- Spation in connection with these educational journeys (as inferred by the travel agencies), then they will be disappointed. Are the travellers aware of how one-sided their intro- duction to the land and its people has been? Guidebooks, catalogues and guides each back up the infor- mation provided the others, thus in- vitably creating the impression that it is correct. Just how superficial the information supplied by guide- books on Morocco is has already been revealed in detail. Although travellers are not plied with a nega- tive picture of Morocco, it is still Bizarre landscapes, historic sites (our nevertheless a very one-sided and illustration shows the casbah in Aït Ben frequently incorrect one. Haddou), art, trade and the flair of the It would be no problem at all for Orient – these are what the (educational) traveller to Morocco expects. travel agencies to change or supple- ment their programmes. But de- mand and satisfaction are so high that there is little incentive for them to alter their strategy. heritage”, on the other hand, be- And, despite all the criticism, ed- come weaker. These changes can ucational travel can compare very also be related to the places visited. favourably with other forms of In the areas of southern Morocco in- tourism. habited by Berbers, none of the or- thodox forms of Islam are to be Prof. Herbert Popp found, and with the absence of Arab Universität Bayreuth 23

german research SPECIAL 2004 Engineering Sciences

he mediaeval workshops were scenes of constant inno- T vation, and the technological processes employed in them can certainly be included amongst the top technologies of that period. With the introduction of the late Gothic ornamental vaults a state of the art was reached which is appli- cable virtually unchanged even today for the performance of comparable tasks. Thus the fig- ured ribbed vaulting found in late Gothic German architec- ture is undoubtedly one of the master products of the stone- mason’s art. Was this sophisti- cated technology based on some comparable theory? The meaning of the term “theo- ry” has changed with the passage of time, and can acquire different meanings even within the space of a single historical epoch. Mea- sured against the understanding of theory which arose with the Italian Renaissance, the German architects of the late Gothic had no theory. But they did possess the criteria for judging whether an architectural form had been created and shaped “in accordance with the rules”. On the other hand, the production of el- evations according to the rules of vault from the plan view, perspective did not form part of the a viewpoint of little conse- teaching syllabus of late Gothic ar- quence for its aesthetic impact. The chitects. architectural drawings in the con- Thus it was essentially models temporary sample collections ex- which were employed to visualise hibit such a high degree of abstrac- the design of a vault. The centring tion that the result of the shaping models which had to be made for processes they were supposed to the master’s examination in the represent could only be elucidated stone-mason’s guilds in southern by actually drawing the required Germany – the so-called “centring views or by preparing a model of the model” supported the ribbing dur- ribbing system. The obscurity of the ing the construction of the building designs can be compared to that of a – furnished only a vague idea of the shorthand text or a musical notation.

The rich and variegated ornamentation of late Gothic vaulting is based on rules now under investigation by scientists using computer simulations; in this way they are succeeding in reading the minds of the contemporary architects

24 The virtual ribbing system of a late Gothic ornamental console. The vault architecture of the Middle Ages ranks amongst the masterpieces of the mason’s art.

ribbed arches and their stones of connection are then determined – something reminiscent of a geo- metrical algorithm. The plan of the vault and the arc derivation in the complicated ribbed vaults of the late Gothic are of no help here in realising a con- cept of what has to be built, but they do determine the form of the ribbing system. Seen from the point of view of a theo- ry, they have the character of a dictum accepted without ques- tion: “This is how it should be!” This is not to say that this set of rules would not have had any practical relevance. When working with preprepared material, as was characteristic of architecture in the late Gothic, the representation of a ribbing system was not based on the projections familiar to us today, such as front and side elevations and cross-sections, but comprised assembly plans in which all the rib Today, more advanced branches, including those on the methods are available based stones of connection, were shown on CAD (Computer Aided Design), unshortened. These assembly plans whose clarity will also permit a sci- were based on the application of entific commentary to be made on certain rules for deriving an arc from the vault designs which we have in- the plan. Just how closely the rib- herited. bing systems reflected these rules In this case the abstraction stems once they had been built has to be not from the making of a cross-sec- checked in each case. The indis- tion of a vault, but extends to the putable fact remains, however, that production of a so-called “arc de- these rules were the foundations rivation”, whereby the ribbing sys- upon which the fantastic forms tem is derived from the plan, and found in late Gothic architecture the shape and spatial position of the were based. What was to appear Ornamental Gothic Vaults from Computer

25 26 The virtual ribbing system of a late Gothic choir (left), a vault plan (below, left) and an ornamental arch (below, right). Right: Computer representation of the choir of a church. rich and complicated could be cre- ated very economically because the concepts behind the standardised individual elements and the shap- ing of the total entity were closely related. Hence we are now able to make computer models of vaults from a plan. Being created accord- ing to the rules of the contemporary stone mason’s art they may justly claim to be historically authentic. We are hoping that this will now en- able us to produce an experimental history of architecture. Prior to mod- elling a vault for which only the plan exists this plan must first be convert- ed into a “true-to-rule” arc deriva- tion. Scarcely any arc derivations are available for existing vaults, but they are available in the plans of later buildings. No-one is going to take all the trouble to boost up an arc derivation in order to model the vault. But it is a different matter when the problem lies in reading the thoughts of the designing archi- tect in order to read his mind re- garding a case in point, and to con- firm this by the experiment. This was achieved, for example, with the ribbing system on the underside of the pulpit steps in St. Stephen’s cathedral in Vienna. The surviving sketch plan was held to be a page from the exercise book of a “not ungifted beginner”, but of no great consequence for the performance of the actual work. In contradiction to this, however, an experiment con- firmed that the original design ex- hibited only minor differences in ap- pearance from the apprentice’s sketch. This plan contains in essence all the information required by a trained stone mason for the practical implementation of this work. The simulation of the ribbing system was achieved using the data we had succeeded in extracting from the drawing.

Prof. Willi Jäger Universität Heidelberg Dr. Werner Müller, Ludwigshafen PD Dr. Norbert Quien, St. Ingbert 27 Life Sciences

n many fields of performance small brains, such as that of the Ifly, can completely outclass large ones, to say nothing of technical sys- tems. One aspect is the rapidity of visual image processing. Thanks to In the Cockpit a broad spectrum of research effort we are now beginning to under- stand the neuronal mechanisms un- derlying this process. Anyone who has observed two flies chasing each other will be con- versant with the breath-taking aeri- al acrobatics these tiny pilots can produce. Whilst the human eye is scarcely capable of even following their flightpaths, the pursuer fly is quite capable of catching its speed- ing prize. To do this it relies to a great extent on its large, faceted eyes, which give it almost all-round vision. The continuous images these eyes deliver to its brain are evaluat- ed in fractions of a second and trans- formed into navigating signals. In order to learn what the fly sees during these breath-taking ma- noeuvres let us imagine we are sit- ting in the fly’s cockpit. Immediately after take-off our environment starts to move past both our eyes from front to rear. Suddenly, the fly makes a sharp turn to the left, whereupon the environment in our field of vision moves temporarily to the right. Then, without any warn- ing, we find ourselves approaching an obstacle. This appears to keep on growing in size, and its contours shift from the middle of our field of vision to the edges. By another sud- den turn to the right, accompanied by broad image shifts to the left, the fly succeeds in avoiding the obsta- cle. Now the target, another fly, comes into view. It, too, is moving, but at a speed different from that of its environment. The resulting rela- tive movement makes the prize visi- ble against its background. The chase can begin. A succession of images such as this is not confined to flies’ eyes, but also occurs with our own eyes, for instance, when driving a car. How- ever, the changes in the in-flight image-flow of flies is many times faster than that experienced by human beings. This is true even of Formula-1 racing drivers or the pi- 28 lots of jet aircraft. Thus flies can make up to ten sudden turns per second, during which they reach angular velocities of up to 5,000 de- grees per second – velocities which no human body could even begin to of the Fly withstand. The fly has proved to be an out- Small brains can completely outclass large ones in their standing model system for tracing the activities in the brain which performance. Thus the fly has proved to be an outstanding serve to process image-flows pro- model system for image processing in the brain ceeding from the eyes. On the one hand, the visual system of the fly is optimised for the performance of this task and, on the other, experi- mental analyses can be conducted here employing a broad spectrum of methods. Every method of investi- gating neuronal circuits can be ap- plied to a largely intact creature, thus making it possible to study the processes occurring in the brain during the actual reception of its natural sensory inputs.

e are now at least able to study basic aspects of the Wneuronal circuits which evaluate the moving images on the retina of a fly. These moving images are not perceived directly by the eye. The fly’s eye, rathermore, sees just a continuously changing array of brightness. From this, the brain has to go through a series of steps to evaluate information on the image movements. In this manner, the flood of information contained in the retinal images is reduced to its es- sentials. The light-perceptive cells on the retina of a fly only register the brightness of its environment. The next higher group of nerve cells, the local movement detectors, compare the brightness data of adjacent light-sensitive cells and react only to a spatial or temporal change in brightness. Movement is signalised when two adjacent light-sensitive cells report the same brightness value in immediate succession, for example, bright-bright. During this process, each motion detector reacts

Thanks to its spherical, faceted eyes, the fly has almost complete all-round vision. This enables it to pursue other flies in flight and at high speed. 29 with maximum strength to move- reliable, in other words, they react images is much greater than that of ment in a given direction. The infor- very differently to the repeated pre- a human being. Hence the film in mation from numerous local motion sentation of a stimulus. Secondly, our “FliMaX” is played at a speed of detectors is summated by integrat- visual stimuli in real behavioural 370 images per second. At this ing neurons. These are able to situations are not, as in an experi- speed the image sequences fuse in recognise characteristic relation- ment, predetermined by an external the fly’s eye to a natural impression ship situations, such as occur, for in- source, but are determined by the as would be seen by the eyes during stance, when a flying body changes manner in which the creature a rapid flight manoeuvre. direction. moves. Current studies in the “FliMaX” We gained our knowledge about In order to study the neuronal suggest that the mechanisms for vi- this from studies based on relatively processing of natural visual stimuli sual image evaluation in flies are simple stimuli, such as black bars we developed a sort of panorama only able to present the brain with moved in front of the fly’s eyes, cinema for flies (“FliMaX”), which the necessary information on the whereby the neural networks for vi- now, for the first time, permits the environment so rapidly and effi- sual image processing were subject- image-flow seen by flies in free ciently because they require rela- ed to electrophysiological analysis. For this analysis, fine measuring probes are introduced into individ- ual nerve cells to register their elec- trical activity. However, these ex- periments cannot tell us how infor- mation relating to the environment

The nerve cell of a fly has been filled with a fluorescent dye. The stained cell is most sensitive to small moving objects. Below: An image-creating process elucidates neuronal information processing. Left, the ramified exit region of a nerve cell can be seen. If something should move in the fly’s field of vision, calcium will flow into the nerve cell. In the image-sequence this is revealed by the increasing intensification of the yellow tone.

in its normal context, for instance, flight to be relayed to a fly under tively few computational elements. when simply flying around, is physical restraint, and simultane- Although these simple mechanisms processed. ously to register the activity of its do not function under every possi- The scientist wishing to study nerve cells. With human beings, se- ble condition, they are nevertheless how these natural visual impres- quential images of a cinema film especially effective when the fly is sions are processed must bear two begin to fuse into a natural impres- within its normal behavioural con- aspects in mind. First, neurons, at sion already at 25 images per sec- text. The processing of the visual least compared to technical compu- ond. However, the temporal ability impressions is thus optimally adapt- 30 tational elements, are extremely un- of the fly’s visual system to resolve ed to the specific conditions of the

german research SPECIAL 2004 The “FliMaX” panorama cinema was developed specifically for studying the brain performance of flies. The fly is located at its centre and looks onto the screen. Fine measuring probes are introduced into its brain from behind.

ing in normal behavioural situa- tions. At the moment, we are contin- uing this development to transform our “virtual fly” into an au- tonomously acting agent capable of navigating in complex environ- ments with degrees of efficiency and virtuosity similar to those of a real fly. Even if the development of this “virtual fly” is being pursued pri- marily for reasons of scientific inter- est, the mechanism of biological in- formation processing could provide valuable leads for the development of technical systems. This has, in fact, already happened in diverse study groups in Europe and the USA, where scientists are using models developed for parts of the motion vision system of flies to de- velop computer chips for use in robot control. Despite this, there is still no technical system at the mo- ment which can meet the demands of flight control so quickly as a fly. Mechanisms for autonomous nav- igation, the avoidance of obstacles and the pursuit of moving targets are of crucial significance in the techni- cal sphere, especially when they are relatively simple and efficient. This is the case with the fly, for it produces its performance with a brain weighing no more than 1 mil- ligram(!). This is most assuredly only possible because the neuronal circuits have had a very much longer test-phase than is possible with any technical system. Or should 200 million years of evolu- tion not have sufficed in the inter- play of mutation and selection to lead to optimally economical and fly’s way of life. Whether these con- what we had already learnt about adequately sophisticated solutions siderations are correct or not will neuronal processing of images, and for equipping the cockpit of the fly? have to be tested using detailed the fact that nerve cells will not al- modelling. For this purpose our re- ways react identically to the same search group has developed a com- stimulus. With the very first version Prof. Martin Egelhaaf puter programme which simulates of a “virtual fly” we were able to ex- Dr. Roland Kern, the neuronal processing of the reti- plain essential aspects of visual Dr. Rafael Kurtz, nal images of flies in free flight. In image processing, including those PD Dr. Anne-Kathrin Warzecha doing this, we took into account found under the conditions obtain- Universität Bielefeld 31

german research SPECIAL 2004

Arts and Humanities Afghanistan: The Culture of the Kafirs

Amongst their Muslim neighbours they had the reputation of being savage idolaters who thirsted after the lives of adherents of Islam – the “Kafirs of the Hindu Kush”

ntil a little resided with the more than a Kati Kafirs in east- Uhundred ern Afghanistan years ago, isolat- and compiled a ed in their narrow, detailed report on wooded, moun- them. This book, tain valleys south being the first- of the Hindu Kush ever and only eye- in north-eastern witness report of Afghanistan, the the Kafirs, en- so-called Kafirs joyed great suc- had succeeded in cess. Thereafter, remaining true to the rulers in their ancient be- Afghanistan liefs and “primi- stopped all further tive” traditions. research activities The mostly steep in Nuristan. Not and narrow val- until 1935 did a leys where they German Hindu dwelt lay remote Kush expedition from the impor- sponsored by the tant routes linking Central Asia and Left: As though they had grown into the Deutsche Forschungsgemeinschaft India. Known to their Islamic neigh- mountain slope, the houses of the village succeed in visiting this region bours as “heathens” – in Arabic, of Nisheigram nestle terrace-like into their again. After World War Two specific surroundings. Above: Two elderly “kafir” – they had the reputation of Nuristanis from Wama in the Pech Valley, field research projects were under- being savage idolaters who thirsted descendants of prestigious Kafirs, supplied taken once again. Most prominent after the lives of Moslems. In the important information for our research among them are the DFG-support- winter of 1895/96, the forces of the project. ed undertakings of the Indologist Emir of Afghanistan finally put an Georg Buddruss and the author. end to their ancient culture. They The cultural characteristics of the were forcibly converted to Islam, Kafirs, from their languages and re- and given the new name “Nurista- ligious beliefs to their individual nis”, the inhabitants of the Land of in Paris. At least a great part of the forms of architecture and settle- Nuristan (“Land of Enlighten- figures in Kabul has reportedly sur- ment, were narrowly regional. In ment”). In this way, a cruel, but vived the chaos of the recent war general, polytheism, strict concepts many-faceted, “primitive” culture, years and the iconoclastic frenzy of of purity and impurity, and a highly richly endowed with deities and an- the Taliban. developed system of feasts-of-merit, cestor figures, was extinguished. It was in the fateful year of 1896 were often found in association with Thirty-one such figures were that the famous work, “The Kafirs of a heroic warrior tradition embracing brought to the court in Kabul in 1896 the Hindu-Kush”, by the British aspects of head-hunting. or shortly thereafter as “trophies”. doctor Sir George Scott Robertson, In line with the five different lan- Many of them landed in the Muse- appeared. From September 1890 to guages spoken, of which four are um of Kabul, four in the Musée October 1891, acting under orders classed as ancient Indo-Iranian id- Guimet and the Musée de l'Homme from the British Raj in India, he had ioms, the Kafir culture numbered 33

german research SPECIAL 2004 five distinctive regional brands. A house in the village of Gurcheilam in the These are the cultures of Waigali- Ashkun region. Left: The anthropoid crown and Ashkun-speakers in the south of a triumphal post “immortalises” the glory of a “big man”. Above, right: The of the region, and those of the Kati- village of Dewa in the Parun Valley. speakers in the north-west and Pilgrims from every region of Kafiristan north-east. Between these, the were drawn to this valley. Right: A minor culture of the Parun Kafirs respected elderly couple in Nisheigram are had spread its roots. One further seated on a plank just as their forebears minor Kafir culture is that of the once sat on their Kafir “benches of Kalasha, who speak a north-west honour”. Indian language. Native to Chitral in north-western Pakistan, this peo- ple escaped enforced Islamisation book. Outstanding amongst these and have been able to preserve regional Kafir cultures is that of the their Kafir culture until today. Parun as this was influenced by reli- Robertson’s detailed description gion to an unusually great degree. only covered the eastern Kati cul- There had once been a time when ture in the Bashgal Valley, near the their massive central temple dedi- border between Afghanistan and cated to the god Mara, located in the Pakistan. The western Kati culture narrow Parun Valley in northern remained unexplored to the last. Kafiristan (Nuristan), attracted pil- Robertson paid only a brief visit to grims from all over Kafiristan. In ad- the Parun Kafirs. In addition to his dition there were numerous smaller observations, important aspects of village and clan temples and assem- their culture have been document- bly halls, whose supporting posts ed in recent decades. Until the pub- bore carvings of deities. The origi- lication of the DFG-supported study nal decoration of some of these by the author in 1999 (see below) buildings survived, surprisingly, the cultures of the Waigal and into the seventies of the 20th centu- 34 Ashkun Kafirs were almost a closed ry, as the author was able to discov-

german research SPECIAL 2004 er. A great many free-standing carvings of deities served as cult fig- ures. These deities are always seat- ed on goats or stools – only the supreme deity, Mara, was shown on horseback. These figures often share gigantic, shield-like, heads, which lend them an extremely bizarre appearance. The Waigal and Ashkun Kafirs, in contrast, were less preoccupied with religious rites and cults which generally involved, in all of Kafiris- tan, the offerings of goats, sheep and cattle. Their prime interest lay in social status, and they outbid each other with great feasts and warlike deeds. In the case of the Waigals, social betterment was sub- ject to important conditions, where- as in the Ashkun region this was not taken so seriously. Successful “big men” announced their own services in the form of tree-high triumphal posts. These were crowned by stereotype human figures. Pegs were hammered into their sides for disclosing the number of people killed. They also had triumphal gates, benches and tomb housings 35 german research SPECIAL 2004 The open hearth is the focus of family life in a Nuristani, formerly Kafir, house. Carved motifs on the posts proclaimed the elevated status of the owner of the house.

sought to impress by their size and the richness of their carvings rather than by any motifs specific to the owner’s rank. Ancestor figures held particular significance for proclaim- ing affluence, family traditions and a firmly established social status. The peripheries of the cemeteries were once “populated” by vast as- semblies of life-sized ancestor fig- ures carved in standing and sitting positions. These included male equestrian figures, occasionally rid- ing on two horses. In the Waigal and Ashkun cultures, on the other hand, ancestor figures were unknown (as was also the case in the Parun cul- ture). Social status was in their case

built, and had the façades and the possessions were chairs of honour Left: A cedar wood post bearing carved interiors of their houses richly with twin backs, wrought-iron status symbols. Cedar was the preferred carved. In particular, the four sup- table- and torch-stands, and silver wood for local architectural and sculptural porting posts round the hearth and wine goblets. art. Centre: These “lovers” once crowned the post of a bench of honour in the the rear wall of the house served to In the case of the Kati culture in Ashkun area. Right: Carving of the display motifs illustrating the princi- the eastern part of the region, power supreme god, Mara, in equestrian pose pal's rank achieved by meritorious and worldly estate were manifested on a post in a clan temple in Dewa in the deeds. Other prestige-promoting in a different manner. Here houses Parun Valley.

36 Engineering Sciences so easy to lose that no ancestor cult like that of the Kati Kafirs had been able to develop. How Engineering One feature unique to the Ashkun culture were the carvings of intertwined “lovers”, over 60 cen- timetres in size, which crowned the learnt to walk smaller posts. Presumably, these were elements from benches of hon- our, whose purpose was to enable When biologists and engineers examine how humans the worthy wife, too, to occupy a place at the side of her “‘big man’ walk, astonishing developments become possible: husband”. for example, four-legged walking machines These lovers vivify the once om- nipresent sexual symbolism of the Kafirs. They originated from iological systems, and espe- predator and the victim, and also, as philosophies which held the world cially animals and human be- is the case with birds and fishes, and to be an animated system subdivid- Bings, walk, swim and fly; tech- even insects, to covering vast dis- ed into antitheses of “male” versus nical transport machines roll, sail tances. The speeds of technical sys- “female”, and “pure” versus “im- and fly. At least, this is the state of tems are several orders of magni- pure”. The Kafirs ascribed every so- affairs today. One typical compo- tude higher. Hence they also de- cial or material success to the inter- nent of biological locomotion is the mand forms of energy not available play of these partial worlds, or to the observance of the laws of purity. Even today, cattle raising is a uniquely male occupation, and only the men may accompany the ani- mals, primarily goats, to the moun- tain pastures, into the world of the indigenous markhor, which by reputation is a particularly pure and sexually potent animal. Women, in contrast, remain responsible for farming. They were regularly ex- posed to the stigma of impureness, and had to withdraw into their re- mote menstruation and maternity houses. The manual workers, moreover, leg, which, in a manner similar to Walking processes have always exerted a were also considered to be funda- that of the wing, evolved in the fascination of their own. One of the first mentally “impure”. These “bari” course of time from the fins of ma- representations of walking people was published back at the beginning of the lived in a form of bondage and were rine animals. An equally typical last century. It stems from the work of the kept largely isolated from village component of technical locomotion photographer Eadweard Muybridge life. Only the Parun Kafirs engaged is the wheel, in a certain sense the (1830–1904). in any craftsmanship themselves. first human artefact which did not Thus the magnificent cultural arte- exist in nature. Legs, wings and fins facts of the Kafirs were all, with the provide a simple solution to logisti- exception of the many deity figures cal problems, such as the trans- to biological systems. Nevertheless, and the other wood carvings creat- portation of loads. Their instrumen- the exploitation of biological re- ed by the Paruni, the products of tal implementation is adapted to sources is incomparably more effi- “impure” craftsmen. After the de- mastering a disordered environ- cient that in engineering. Which struction which accompanied Is- ment frequently subject to unpre- also applies to walking. So, despite lamisation and many decades of dictable change; technical locomo- the completely different problems sale to antique dealers and deliber- tion requires, at least on land, or- confronting biology and engineer- ate clearances only very few of ganised tracks and areas of ground, ing, it is worth taking a look at how these witnesses now survive in ships require harbours, and aero- biology solves these problems. In Nuristan. planes runways. terms of quality, efficiency and in- The speeds of biological locomo- telligence, technical walking is far Dr. Max Klimburg tion are very modest, and are often removed from biological walking. Universität Wien/Museum orientated towards the demands of The biological design of propul- für Völkerkunde München hunters and the hunted, of the sion systems, for instance, acting 37

german research SPECIAL 2004 through the medium of joints and with redundancy, so that informa- machines are the most commonly muscles, is more effective, usually tion on the momentary state of mo- built, followed by four-legged ones, also lighter, and certainly more tion is available to the control struc- as these provide good locomotive adaptable and economical in terms tures both inside and outside the stability. Two-legged machines are of energy than anything available in brain to a degree unmatchable by not so common, as walking on two engineering. Moreover, groups of engineers. The astonishing thing legs always involves dynamic ele- muscles often offer a certain redun- here is that novel and unknown ments, too, and is thus more difficult dancy of motor effort which can be physical principles are involved to put into practice. of advantage, for example, should only in rare cases, but the familiar For years now, the stick insect, some muscles tire. Biological control ones already available are applied which has been the subject of in- tense biological research, has been serving as the model for six-legged mo- tion. Germany leads the world in this respect. Some of the six-legged walking machines made in Ger- many, and in the USA and Japan, too, have used this leg design, and have achieved great practical success after a decen- tralised control structure analogous to that found in stick insects has been adopted. This has now be- come the commonest con- trol structure in the world for six-legged robots. One problem affecting the practical realisation of such technical legs lies in the ratio between the instal- lable performance of their joints and their weight. In biological terms, this per- formance:weight ratio de- clines by the power of 1.5 of the geometrical dimen- sions. The volume of a liv- ing organism, and thus its weight, grows as the cube of its size, but its muscle power only grows as the concepts react quickly and intelli- The stick insect has been serving engineers square of its dimensions, as it is ap- gently to changes in the environ- as a model for six-legged walking for a proximately proportional to the ment. This is technically almost im- long time now. This leg design has been cross-sectional area of the muscle. adopted for applications involving robots, possible to imitate at the present with electric motors substituting for the This produces a steadily declining time. Biological systems contain au- muscle drives. performance:weight ratio as ani- todidactic properties which greatly mals become larger, whereas small- enhance their adaptability and fa- er animals, such as ants, mostly ex- cilitate a certain degree of self-re- and implemented to much better hibit high ratios. So, if a six-legged pair. The first steps towards self-re- purpose. In the course of millions of machine is built according to the pairing systems have been taken in years of evolution, the leg, as the model provided by insects, it is im- the sphere of space travel, but we central instrument of walking, has possible to achieve their perfor- are still far removed from biological adapted itself to the most diverse mance:weight ratio by technical perfection. demands of this motion. Anyone means. The arrays of sensors available to wishing to build walking machines There are probably only 20 to 30 biological systems are breathtaking. should first take a look at what na- such six-legged machines in the Biological sensors monitor every de- ture has to offer in the way of design whole world, and about half as 38 tail of the course of a movement, and concepts. In engineering, six-legged many four-legged ones. If we take

german research SPECIAL 2004 biological four-legged animals, the naturally enough, on the human of complicated biological structures. technical problem on the evidence model, whose walking characteris- Engineers give a different answer: becomes quite clear: from mice to tics have already been under inves- they see themselves as “implemen- elephants, and from piping hares to tigation for many decades. Hence tation scientists”. The engineer horses, four-legged animals walk, the kinematic sequences are per- hopes that biology will furnish ideas trot and canter, whereby they use fectly familiar, but, although much and inspiration for his formative motor areas, in some cases domi- is also known of the supporting sen- tasks. nantly, which can only be stabilised sor mechanisms, much has yet to be A further aim, which has already dynamically and no longer exhibit learnt. Consequently, in the priority been partially realised today, is to use any properties of static stability. As programme “Autonomous Walk- walking machines in areas inaccessi- a consequence, not only are the pat- ing”, doctors and biologists are also ble to human beings, for example terns of motion more complicated, studying the motor sequences and where chemical or nuclear con- because they include jumps, stabili- learning processes associated with tamination is present, or for fire-fight- sation in the air, and shock avoid- walking. They are also now con- ing, for working under water and in ance during the brief contacts with structing a two-legged machine pipes, and for waste-water drainage. the ground, but the demands made which, in contrast to former devel- Walking machines may also be used on the control structures with their opments, will be able to walk dy- for performing routine tasks in of- lavish adaptive and intelligent namically. In this respect it is a de- fices, hospitals or households. The properties, such as those controlling parture from the developments technological know-how gained the eye movements, become incom- achieved by the Japanese, the through building such machines parably greater than is the case with world leaders in the field of two- could be directly transferred to artifi- six-legged animals. Two four- legged walking machines. One ma- cial limbs, as Japanese projects have legged machines are being devel- chine which is already at a very ad- impressively demonstrated. oped and built within the frame- vanced stage is WABIAN, whose as- work of the DFG-sponsored priority tonishing performance is only ex- Prof. Friedrich Pfeiffer programme “Autonomous Walk- ceeded by that of Honda-man, Technische Universität München ing”. Four-legged machines offer a which is apparently even more skil- Prof. Holk Cruse series of advantages: they are quick, ful. Honda, however, are not releas- Universität mobile, better able to surmount ob- ing any technical data. Bielefeld stacles, and the fact Why is it that scientists are con- that they have only centrating so much on studying four legs and not six walking machines? From the bi- means that they de- ologist’s point of view, the mand less technical main reason is scientific effort. curiosity, and thus the Two-legged desire to improve walking machines our under- are orientated, standing Life Sciences

he impact of man on the future development of the climate Tand the dynamics of ecosys- tems can only be realistically evalu- ated if their geological history is known. The time-window of the Eocene – the period from 54 to 33 million years ago – is of exceptional interest in this connection for this was the last time that the world was to have a largely uniformly distrib- uted warm climate exhibiting cer- tain characteristics of the popularly awaited “greenhouse climate”. Moreover, it was at that period that the explosive development of the mammals and flowering plants began. Thus for the first and only time in the history of the earth the preconditions now obtain for a direct comparison of today’s – and possibly future – current processes with those in a “greenhouse cli- mate” still uninfluenced by man. The Middle Eocene Eckfeld Maar near Manderscheid in the Volcanic Eifel has proved to be an ideal sub- ject for research into such questions. Its sediments have preserved not only a plethora of plant and animal chemo-, micro- and macrofossils, but they also hold a broad spectrum of palaeoclimatic information. The Eckfeld Maar is a unique geological archive in which the natural fluctua- tions of the climate and their impacts on flora and fauna are documented over a period of tens of A Climatic thousands of years in the Middle Eocene. The Eckfeld Maar lies together with two further volcanic edifices of Archive with the Middle Eocene epoch on the southern periphery of the High Eifel volcanic field. Its four hundred or so volcanoes bear witness to the fact Hide and Hair that this region of the High Eifel was the scene of violent and continuous volcanic activity from the Middle Eocene to the Lower Miocene. Both the pollen spectrum and the mam- Over 35 million years ago, the global climate exhibited malian fauna indicate that the Eck- characteristics of the popularly awaited “greenhouse climate”. feld Maar erupted in the Middle Eocene, giving it an estimated age The sediments of the Eckfeld Maar in the Eifel are of 44 to 45 million years. Weathered yielding numerous witnesses to that period volcanic rocks from the Eckfeld Maar are nothing new and may be assumed to have been ejected during the eruption of the Maar. Hence one aim of the core drilling 40 programme in 1996 was to obtain

german research SPECIAL 2004 At the onset of oil shale formation the lake was chemically stratified: its body of water comprised an upper, oxygen-rich part, and a lower, low-oxygen part with a high content of dissolved minerals and a correspondingly high density. In the long term, this special feature pre- vented any regular mixing of both

When these beetles, fishes and “dawn horses” were still living near the little town of Manderscheid in the Eifel, the local maar, surrounded by lush tropical vegetation, looked like the Ranu Lading in Java.

unweathered volcanic rocks for down to 210 metres in depth, rapidly radiometric age determination. One filled with groundwater. The result- volcanic scoria was shown to be 44.3 ing lake was originally at least 110 ± 0.4 million years old – an age metres deep, possibly going down which coincides with the biostrati- to 150 metres. The gross masses of graphic estimates, and marks both volcanic detritus forming its bottom the emergence of the crater itself were initially covered by a sequence and also the age of the fossils. This of light coloured, finely stratified has thus presented Europe with its clays only a few metres thick. These first numerical dating of a continen- were then covered almost as a mat- tal biocenosis from the Eocene. ter of course by dark coloured oil Once the eruptions had run their shales, which probably formed over course, the crater of the Eckfeld a period of less than 250,000 years, Maar, up to 1,000 metres in size and and gradually filled the lake. 41

german research SPECIAL 2004 bodies of water, or any colonisation even the “contents of their stom- amphibians, reptiles, birds or mam- of the lake bottom by, for example, achs” have been preserved for mals also document the extraordi- burrowing organisms. This explains posterity. nary potential for preservation in the perfect preservation of both the In addition to algae, fungi, mosses these sediments of the Eckfeld finest sedimentary structures and and ferns, the flora embraces a mul- Maar. The commonest and richest the organisms which had sunk titude of seed-bearing plants. Some in species are, as might be expected, down to the lake bottom. The re- two hundred genera found in a sin- the insects, twelve orders of which duced degree of recycling of organ- gle profile section only some three have already been discovered. ic material in the depths of the lake metres thick bear witness to wood- Evidence of amphibians, in contrast, ensured the survival of even com- lands rich in species, whose bank is only presented by a single partial plex organic molecules. Although, communities were quite evidently skeleton of a frog. This is surprising, of course, the steepness and insta- characterised by lianas. Thousands but understandable considering bility of the early banks would of leaves, fruits and seeds have the steep banks of the lake and its certainly have inhibited any major been found. Almost eight hundred special hydrochemism. Amongst colonisation of the bank region by flowers and inflorescences from the numerous finds, already aquatic plants and terrestrial organ- different families have now been embracing over twenty different isms, it is obvious that the special recovered. Their significance lies, species of mammal, the first remains chemical conditions at the deeper firstly, in the fact that most of their of two primate species and five skeletons of the “dawn horse” genus Propalaeotherium are espe- cially worthy of mention. Also of importance are the first-ever finds of undeformed skulls of this genus. In the Middle Eocene a uniformly warm climate prevailed world-wide far into the northern latitudes. This is also confirmed by bioindicators found in the Eckfeld fossil beds, such as palms and crocodiles. Eckfeld, however, is able to furnish much more detailed information on the climate of the Middle Eocene, for maar lakes, as recent studies have shown, are high-resolution climatic archives. This is because we are concerned here with so-called “varvites”, whose fine laminations occur due to annual and levels would also have strongly in- The Eckfeld Maar, on the southern edge of even seasonal periodicities, en- fluenced the colonisation conditions the Volcanic Eifel, presents scientists with a abling them to store sedimentary of the surface water when, for time-window on the Eocene (54–33 million and biological events with the maxi- instance, occasional collapses of the years ago), the last epoch in which a global mum conceivable temporal differ- “greenhouse climate” prevailed. banks or violent storms had led to entiation. Recently conducted spec- partial intermingling of the two tral analyses of finely laminated oil bodies of water. This aspect led to shale samples from Eckfeld have an episodic, and fairly significant, anthers still contain pollen, and can revealed high frequency solar peri- intoxication of the surface water, thus help to elucidate the systematic odicities. This, together with the fact which would explain the compara- position of forms of pollen hitherto that, due to the former latitude of tively narrow spectrum of biodiver- only found in isolated cases. And, Eckfeld (approx. 42°–44°N) we can sity amongst the lake-dwelling secondly, in the information they assume a well defined seasonality, organisms, and the observation that provide on the co-evolution of flow- permits the conclusion that the these were in part, at least, species ering plants and insects. The high accumulation of the Eckfeld oil impervious to fluctuating salinity. degree with which interactions be- shale followed an annual rhythm. The species and individuals of tween both groups can be deduced Hence here, too, we are concerned terrestrial organisms, on the other directly from the fossils is shown by with varvite, and the current hand, have been richly document- a “honey bee” which, even today, is spectral analytical evaluation of the ed, and are for the most part excel- still carrying pollen on its body and oil shale drillings from 1996 and lently preserved. Thus, for example, hind legs. 1999 might well reveal the exis- species of beetles, with their Finds of such diverse groups as tence of even longer-term extrater- original structural colouring, and freshwater sponges, mussels, snails, restrial periodicities (Milankovitch 42 mammals with “hide and hair”, and ostracods, arachnids, insects, fishes, cycles).

german research SPECIAL 2004 The magnetisability of the rock over the entire oil shale profile was also determined in steps of one mil- limetre with a spatial resolution of 4 millimetres. Based on an assumed mean annual oil-shale sedimenta- tion rate of 0.4 mm, this would corre- spond to a temporal resolution of ap- proximately ten years. The resulting curve yields the medium- to long- term climatic fluctuations. The first indications of climatic fluctuations soon came to light from analyses of the oxygen and carbon isotopes formed from the iron (ferrous) car- bonate in the Eckfeld Lake. Copious series of samples from the new cores are now available for further studies.

he current interdisciplinary evaluations of palaeo-climatic Tdata are producing a detailed reconstruction of these climatic fluc- tuations and an analysis of their pos- sible causes. The crosslinking of these palaeoclimatic data with the finds and findings solely retrievable from excavations is creating an op- portunity to analyse the effects of cli- matic fluctuations on the ecosystem of Eckfeld and the dynamics of these changes for the approx. 11,000 years so far covered by the excavations. The over 30,000 fossils already re- covered form an indispensable data base for this. Favourable circumstances have led to deposition of other sediments from this epoch in the western Eifel, This “dawn horse” mare and foal were bears a close similarity to Messel. in addition to those in the Eckfeld found in the Eckfeld Maar. The dark mass in Bearing in mind the fact that the Maar. These have enabled scientists the body cavity is a dense package of leaf latest finds show that Messel might to make rough reconstructions of fragments. also once have been a maar, then the Middle Eocene relief and the re- these shared features are easy to ex- gional drainage system, so that the plain, although Messel was formed finds made in the Eckfeld Maar can in the Lower Middle Eocene, mak- now be placed into a palaeographic indications of a temporary connec- ing it four to five million years older, framework. We now know that the tion between the Eckfeld Maar and and opens a window onto an earlier centre of the Tertiary High Eifel vol- the Manderscheid river. This system phase of the Eocene climatic opti- canic field, which lies some 20 kilo- debouched into the original course mum. Hence, studying the finds in metres north of Eckfeld, towered of the River Saar in the Arenrath both sources together offers a several hundred metres above the basin, a few kilometres to the south- unique opportunity for multidisci- surrounding landscape and con- west of Eckfeld, whose sediments – plinary research within the time- tained the source of the Mander- sand and gravel with occasional in- window of the Middle Eocene – the scheid river. This flowed west of clusions of plant-bearing clay lenses last epoch in which a global “green- Eckfeld as a boundary river of the – are still widely distributed over the house climate” prevailed. Buntsandstein escarpment. At that western Eifel. The plant fossils – no period, this escarpment, which rises animal remains have as yet been Dr. Herbert Lutz up to 200 metres, was probably less identified – permit reconstruction of Dr. Franz-Otto Neuffer than 4 kilometres away from the the vegetation along the riverside. Naturhistorisches Museum Mainz Eckfeld Maar. The current excava- In its sediments and fossils, and Landessammlung für tions have already produced the first their state of preservation, Eckfeld Naturkunde Rheinland-Pfalz 43

german research SPECIAL 2004 Natural Sciences

Expedition to the Volcanoes of the Arctic Seafloor

The AMORE Expedition headed for the so-called “Gakkel Ridge” where, on the floor of the Arctic Ocean, there is hot work afoot – for this ocean ridge is composed of active volcanoes

44 Three research vessels meet in the Arctic Ocean: The RSV “Polarstern” and “USCGC Healy” have yet to ply their way to the Pole through the icy water, the Swedish “Oden” (foreground) has already completed its mission.

45 hen Jules Verne made his Magnetic measurements made from imaginary journey of ex- helicopters indicate that these sub- Wploration to the centre of marine volcanoes were active over the earth through the vents in an very lengthy geological periods. Icelandic volcano over a hundred The geophysical measurements un- years ago, he assumed that all vol- dertaken along the Gakkel Ridge, canoes are interlinked in a subter- and especially studies of the adja- ranean system. But even his imagi- cent basins, revealed that not only nation failed to visualise the world- does the thickness of the sediments wide system of submarine volca- under the ocean floor, otherwise so noes that extends over a distance of level, vary greatly, but also that a over 60,000 kilometres and only part of this sedimentary cover has breaks the surface of the ocean at been transported into the ocean Iceland. This mid-oceanic ridge, basins from the neighbouring conti- which spans the entire world ocean, nental shelf edges by dramatic has evolved along the boundaries slides. between the tectonic plates of the Under the two-metre layer of ice Earth’s crust. Gakkel Ridge, in the and the 4,000-metre-deep Arctic central eastern Arctic Ocean is the Ocean lay the volcanoes from which northern most spur of the plate the samples were to be taken using boundary between Eurasia and TV-controlled grabs and dredges. North America, and at the same These basic tools returned with time the most slowly opening ridge loads of up to three tonnes of rock segment in the world, opening only from the ocean floor to the surface in a few millimetres each year. one lift. Initially, we had expected In October 2001, the research that this submarine ridge would vessel RSV “Polarstern” and the most probably have been the result ice-breaker USCGC “Healy” from of extrusion caused by tectonic the U.S. Coastguard returned to movements rather than by any vol- port bringing dramatic data from canic processes, and so we had ex- an expedition to pected to find a the Gakkel Ridge majority of peri- which lasted over Probes measure ice dotites and gab- four months. The and melt-water. bros in the sam- AMORE 2001 ples. Peridotites (Arctic Mid- The data recount the deep-seated Ocean Ridge Ex- climatic changes rocks from the pedition) marks earth’s upper a milestone in in the Arctic mantle, and gab- Arctic Ocean ex- bros form in the ploration in that lower oceanic scientists have for the first time crust, so that both types of rock can accurately charted, surveyed and only be brought to the surface of the sampled the western part of the ocean floor by tectonic movements. Gakkel Ridge. And these rocks were indeed found Geophysical surveys were con- in many locations. ducted to determine the thickness of The majority of the rock samples, the crust along the Gakkel Ridge however, were found to contain and its adjacent ocean basins. Initial basalts, the solidified products of evaluation of the data shows that volcanic eruptions from submarine the crust thickness along the volcanoes. The shapes of the sam- Gakkel Ridge, which varies be- ples reflected the violence of the tween six kilometres and a few hun- clash of red-hot lava with ice-cold dred metres, does not accord with sea water during these submarine existing model concepts. In contrast eruptions. The freshly expelled lava to previous assumptions, it now ap- solidifies to a thick, black, tubular pears that there are magmatic cen- glass periphery into which the lava tres spaced at regular intervals flows, rather like blowing up a bal- along the ridge, where clearly loon. In the course of this process, greater accumulations of basalt so-called basalt pillows are created 46 have formed than in the other parts. to form the upper 2,000 metres or so

german research SPECIAL 2004 A helicopter flying at an altitude of 20 metres measures the thickness of the ice cover beneath it using a helicopter electromagnetic probe (“HEM-Bird”). Left: Magnetic fields are also probed. Above: A basalt sample from the ocean floor. The “giant pillow” weighs several tonnes.

ple only a few hours after the rocks were recovered. The composition of the rocks measured on board coin- cided roughly with what had been expected. However, as these stud- ies point to the existence of a thin crust along the entire Gakkel Ridge, and thus stand in contrast to the vio- lent volcanic activity observed, more detailed studies must now be undertaken to elucidate the ratio of the oceanic crust. These basalts between the rate of spreading and contained a variety of types, which the thickness of the ridge crust. we had not expected to meet on the Examination of the “hot springs” Gakkel Ridge. In particular, the under the Arctic Ocean was also on high proportion of interspersed the expedition’s agenda – springs, crystals in the rock can only be ex- whose chemical composition is plained by the presence of large rather more reminiscent of a witch’s magma chambers, and stands in cauldron. Mid-oceanic ridges are clear contrast to the conventional the scenes of broadly spread and wisdom that the extremely slowly quantitatively very significant hy- spreading Gakkel Ridge simply drothermal exchange processes be- doesn’t produce enough magma to tween the rocks of the oceanic crust keep such chambers in operation. and the water columns. Where After the initial assessment of the these springs discharge, at their so- rock samples, thin sections were called “vents”, highly specialised prepared on board ship. Microscop- communities of invertebrates are ic measurement of the optical prop- often found which, to judge by their erties of these sections enabled us to external appearance, should not ac- make precise statements regarding tually dwell in the ocean depths. the composition and origin of a sam- They include, for example, large 47

german research SPECIAL 2004 Smaller-sized air guns towed through the ice behind the ship generate acoustic signals to obtain geophysical reflections. Above: Gigantic ice flows with blue pools of melt water. The weathered surface is typical of the summer. Right: A TV-controlled “grab” brings samples up to the surface from the ocean floor.

tube worms and mussels which have adapted to a very specific form of metabolism. Back in 1998, the “Polarstern” had collected vent fauna of this sort along the conti- nental shelf of the Laptev Sea off Siberia, from the immediate prolon- gation of the Gakkel Ridge. They testify to the possible presence even more of them further to the west, and are the best proof of the broad distribution of hydrothermal springs further along the Gakkel Ridge. Every exploration of the ocean able to ravel submerged under the favourable ice conditions, were able floor demands accurate charting. ice and make a continuous depth to survey the northern and southern Although such charts are a matter of profile, and thus to compile a chart. flanks of the Gakkel Ridge respec- course for seas in temperate lati- However, due to the relative inac- tively while satellite navigation fa- tudes, knowledge of ocean floor curacy of the navigation facilities in cilities allowed them to make highly morphology of the Arctic Ocean up the submarines, this proved to be accurate fixes of their positions. One to this point had been very broad somewhat problematic, as much of very valuable result of this expedi- brush, having been passed on to a the planning for the AMORE Expe- tion was the resulting detailed and very restricted circle of people by dition was based on this chart. How- extremely precise cartographic the U.S. Navy, which had from time ever, the “Polarstern” and the record made of the morphology of a to time made nuclear submarines “Healy”, working independently stretch of the Gakkel Ridge extend- 48 available. These submarines are and over long distances under ing over a distance of almost 900

german research SPECIAL 2004 diameter. Interspersed between diverse types of surface. Observing these were narrow channels already the feeding habits of minor inverte- bearing a covering of new ice. Com- brates which had adapted to the ex- parisons with 1991 revealed marked treme living conditions in brine changes in the observed thickness channels in the ice flows, and whose of the ice. Whereas the typical thick- body fluid did not freeze, proved ness in 1991 was 2.5 metres, this very exciting. year it lay between 1.9 and 2.1 me- tres. These measurements were for he northern Arctic Ocean is the most part made using an elec- permanently covered by pack tromagnetic probe carried on a Tice today, even though the ex- sledge that was dragged over the change processes with the adjacent frequently rough terrain presented seas and the seasonal melting by the ice. In this manner a total of processes ensure that this sea ice 52 ice flows were surveyed over a never lasts for more than a few years. distance of 100 kilometres. Howev- The task of the marine geologists er, new types of probe were also was to take sediment cores from the employed which enabled the thick- region off the great Siberian shelf. ness of the ice to be measured from As terrestrial sediment sequences a moving ship or a helicopter. In are often subject to major errors in particular, the new “HEM-Bird”, a dating we are hoping that these sub- geophysical probe drawn along marine cores will help to throw fur- under a helicopter on a 20-metre ther light on chronological process- cable, enabled the acquisition of es. Major ice shields on the adjacent data of surprisingly high quality. land areas can be identified in the These measurements of the ice Arctic Ocean sediments through coarse and fine rock residues carried by the icebergs. The sediment cores from the Gakkel Ridge at 70 degrees East, which had never previously been subject sampled, were indeed found to contain a number of layers of coarse sand and stones, typical sediments from the melting phases of great glaciers. From the variously coloured layers in the sedimentary cores we were able to estimate that these were around 200,000 years old. Laboratory studies are now ex- pected to provide more precise dat- ing and to reveal the extent of the glaciation in Northern Siberia in its individual phases, the role played by the transport of moisture from ephemeral stretches of open water in the build-up of the ice, and the points in time when the melt water of the warm phases of melting glaciers reached the ocean. km. One of the purposes of the ex- thickness also served as preparation pedition was to observe changes in for the European Space Agency’s Prof. Jörn Thiede the thickness and distribution of the (ESA) “Cryo-Sat” satellite mission, Dr. Christian Haas ice and to compare the results with due to map the Arctic and Antarctic Dr. Wilfried Jokat previous measurements made by ice cover beginning in 2004. Mea- Alfred-Wegener-Institut “Polarstern” in the central Arctic surement of the sea ice also includ- Bremerhaven Ocean in 1991 and 1998. In summer ed determination of the physical PD Dr. Richard Mühe 2001, no extensive areas of water and biological properties of the ice Universität Kiel were encountered at the North Pole. and melt pools. In addition to this, Dr. Robert Spielhagen Over 90 per cent of the surface was we drilled ice cores, evaluated satel- GEOMAR Kiel covered by large flows of multi-year lite and aerial photographs, and de- PD Dr. Jonathan Snow ice measuring several kilometres in termined the reflective capacity of MPI für Chemie, Mainz 49

german research SPECIAL 2004 Life Sciences

When Plants Tell of Their Environment

The flora of the southern Aegean area provides valuable pointers for agriculture and forestry to the climate and the constitution of soils

50 The plant world of the southern Aegean is as diverse as the landscape. The flora found on small uninhabited islands, such as the Gramvousa Islands off the north-western coast of Crete, often differs markedly from that found on Crete itself.

51 lants can act as indicators by crucial hints for range management. furnishing information on their It can also supply information for re- P environment. Such bioindica- gional tourist development. These tion, however, presupposes the abil- indicator values are also of signifi- ity to recognise the indicative quali- cance for the cultivation of Southern ties of the plants with respect to es- Aegean plants, many of which are sential soil and climate parameters. potentially or actually endangered, Appropriate numerical values have where precise knowledge of their now been provided for the first time demands on habitats is a vital ele- for a large floristic domain in south- ment that biodiversity research can ern Europe, with the Aegean area of contribute to species conservation. Greece being used as an example. Ecological preferences can also pro- A by-product of this study was the vide criteria for the systematist discovery of hitherto unknown plant when he delimits, classifies and species. The species composition, vitality and structure of the plant cover of a given area reflect the main features of an ecosystem’s habitat character- istics. Many plants grow on soils with special properties such as high moisture, very low nitrogen content, or high acidity, or they may only grow under a given temperature regime. As a result, they acquire in- dicator value and can be used for habitat classification, environmen- tal (passive) monitoring or for eco- logical interpretation of specific vegetation sectors. Indicator plants are pointers to the energy-matter budget of nature, and especially of its bioeffective system components and, naturally, also of anthro- pogenic and biotic influences. Forest botany and the study of for- est habitats has resulted in the accu- mulation of a wealth of knowledge on the habitat conditions under which plants strive in central Eu- rope. “Pflanzensoziologische Exkur- sionsflora”, the standard work writ- ten by the forest botanist Erich Oberdorfer, and already in its sev- enth edition, contains copious data of this kind. Heinz Ellenberg’s sys- tem of “indicator values” is a break- When the snow melts, crocuses (Crocus through towards a “numerical” sieberi) (left) bloom in the moist mountains treatment of phytoindication, and of Crete. Thorny chicory (above,right) is a thus to its quantification and further popular wild vegetable. The remains of terracing walls bear witness to the former operationalisation. Starting from much more intensive use of the landscape five-value scales for segetal weeds, and higher settlement density. Many a he developed nine-to-twelve-point plant’s distribution pattern can only be indicator value scales for the ferns explained against a historical background. and flowering plants of central Eu- rope. The potential practical applica- tions of this system are legion. It can names plant taxa. Ellenberg’s tem- aid farmers introducing novel crop perature scale covers values from plants, or assist forest planners se- one to nine. In each case, the lowest 52 lecting tree species, or it can furnish value reflects the minimum intensi-

german research SPECIAL 2004 ty of a habitat factor, and the top seum of the Free University in Berlin Extensive studies are needed in value the highest intensity, whilst have been engaged in a research order to assess the ecological be- the intermediate values indicate the project entitled “Indicator Values haviour of plants. The work centres transition between the extremes. for the Vascular Plant Flora of the on vegetation analyses, repeated in Plants with a temperature value of Southern Aegean Area (Greece)”. different seasons for complemen- one are indicators of cold, and only The South Aegean phytogeographi- tarity, combined with complex occur at high elevations in the cal province extends from the island habitat characterisation. Soil sam- mountains. Temperature value of Kythera in the west, via Crete and ples were analysed at the Landwirt- three is allocated to the indicators of Karpathos, to Rhodes in the east. It schaftliche Untersuchungs- und cool conditions, which are found hosts approximately 2,500 species Forschungsanstalt Augustenberg mainly in sub-alpine habitats. The and sub-species of higher plants (LUFA) and the results were com- indicators of moderate warmth (excluding Mosses, Lichens, Fungi, bined with the floristic and ecologi- (temperature value five) are plants and Algae). The aim of the project is cal data in a databank, which also of the lowlands and hills, with their to determine ecological indicator holds literature and herbarium greatest concentration in the sub- data. The identification of plants montane temperate belt. Tempera- that cannot be named with confi- ture value seven is allocated to indi- dence in the field is a time-consum- cators of heat, and nine to “extreme ing process that requires compari- heat”, centred on the Mediter- son with the voluminous reference ranean in this distribution. Logical- collections (herbaria) and consulta- ly, plant species with a broad eco- tion of the specialised library of the logical amplitude with respect to a Botanical Museum Berlin-Dahlem. given habitat factor, in other words, Correct determination of the plant which occur over a broad range taxa is essential for high quality of habitats, have no indicator func- results, being an indispensable tion. Such plants are described as basis for any studies of vegetation “indifferent” with regard to their ecology. preferences. Using mean or domi- Despite the fact that Crete, floris- nant indicator values, phytoindica- tically speaking, is one of the best tion will enable an area to be classi- known regions in the Mediter- fied by means of detailed ecological ranean area, it has still been good maps (climate maps, soil-condi- for surprises, too. Thus, for instance, tions) drawn to a variety of scales. It Trifolium phitosianum, a species of is hardly sufficient to base gener- clover, had to be described as a alised statements on locally made species new to science. This is a measurements alone, but the almost small annual herb whose distribu- omnipresent vegetation – com- tion appears to be confined to the bined, for greater security, with the eastern end of Crete, underscoring geomorphological features – en- the importance of Crete as a centre sures the effective production of of diversity of the genus Trifolium such maps. Today, just on fifty years (38 species and sub-species). Fur- after its introduction, Ellenberg’s in- ther new species are awaiting their dicator value system is in general description, many have been use for resolving questions of plant recorded for the first time in the pro- ecology and regional planning. It ject area. has been extended, in a slightly In the medium term, the opportu- modified form, beyond its original values with respect to temperature, nity now exists to develop a pan-Eu- range to be used in neighbouring moisture, nitrogen and light supply, ropean system of indicator values areas such as Scandinavia, Poland, plus soil acidity and salinity, aug- by working north from the Southern Hungary, Romania, the Benelux mented by further specific indicator Aegean area in southernmost Eu- countries and Great Britain. Until functions for all flowering plants and rope to close the gap between this recently, no corresponding studies ferns. To achieve this, Ellenberg’s and central Europe. were available for any regional flora indicator value system had to be of southern Europe. Only in 1994 modified by adapting the scale of Dr. Niels Böhling was an indicator value table pro- temperatures to the much warmer Kirchheim unter Teck duced to evaluate the indicator conditions prevailing in the south- Prof. Werner Greuter properties of the flora of the Greek ern Mediterranean. The aridity of Dr. Thomas Raus island of Naxos, with its diverse the Mediterranean habitats also ex- Freie Universität Berlin landscape. ceeds that for central Europe, which Botanischer Garten Since 1997, scientists at the entailed a different spectrum of und Botanisches Museum, Botanic Garden and Botanical Mu- moisture values. Berlin-Dahlem 53

german research SPECIAL 2004

Engineering Sciences A Peep into a Different World

Microsystems technology holds great potential for novel products in medicine, analysis and electronics – a collaborative research centre in Aachen is elaborating the necessary principles

o elaborate the principles for these microcomponents are only the production of microsys- perceptible using optical instru- T tems in hybrid (mixed) modes ments. Having once seen the diver- of construction – this is the aim of sity of minute individual compo- the basic research currently being nents comprising a microsystem the conducted by the collaborative re- problem is immediately obvious: search centre established in 1997 at how can these tiny components be the Rheinisch-Westfälische Tech- handled, joined together, and then nische Hochschule (RWTH) Aachen assembled to form a complete com- entitled “Assembly of Hybrid Mi- ponent? crosystems”. Five institutes of the In the simplest case, handling is RWTH Aachen and two Fraunhofer effected using a magnifying glass institutes from Aachen are collabo- and a pair of tweezers. Having said rating closely on the processes re- this, the two main tasks in this quired for handling and joining the process have already been de- microcomponents. The details of scribed: the moving and positioning of the tiny components, and the ob- servation and monitoring of this process. A variety of instruments are required for this, of which one of the most important are the pincers. In view of the small size of these mi- 300µm crosystems, the pincers must not be much larger than the components. Their points should therefore only be a few micrometres in thickness and width. This is the only way in which even difficult assembly posi- tions can be reached.

A look into the large-chamber scanning electron microscope at the Fraunhofer Institute for Production Engineering in Aachen. Here, tiny components – for example, gears – are combined into microsystems (small photo). 55 Physical properties often act dif- stress. If damage is to be avoided both the micro- and the millimetre ferently at the micro-level or may the selection of the pincers’ drive ranges. The demands placed upon lead to different effects from those system is of crucial importance. the assembly unit’s ability to adapt familiar in the “macroworld”. For Piezo elements, which change their to variations in size are therefore example, the behaviour of handling length proportionally to the applied much higher than has hitherto been devices is normally largely deter- stress, and thus enable infinitely the case. The gripping width and mined by their weight. Whereas the fine adjustments to be made, have the form of the points of the pincers, for example, have to be adjusted accordingly. It is safe to say that there will never be a pair of univer- sal pincers capable of gripping every component employed in mi- crosystems engineering. One attractive possibility for monitoring the assembly process is offered by the scanning electron mi- croscope (SEM). These instruments

200µm

The steel wires welded together in the SEM are only 175 micrometres thick (above). Small photo: Mechanical pincers help when handling tiny components. Right: A microwelded seam.

force exerted by their weight de- creases by the power of 3 of the di- mensions, the surface forces only decrease by the power of 2. As a consequence, the micro-objects which have been gripped may ad- here to the pincers when these are opened. In terms of micro-assembly, this means that special countermea- sures have to be found. One ap- proach is to join the already posi- tioned components to other compo- nents whilst they are still in the 50µm grasp of the pincers. The small size of microcompo- nents produces further challenges. proved to be particularly effective. achieve much greater magnifica- Thus the areas available for grip- Components in microsystems engi- tions (up to 300,000 times) than light ping by the pincers are also very neering differ in form from those microscopes, although the crucial small. Gripping with the pincers found in microelectronics. Their advantage for microassembly lies, can lead to extremely high pres- size-range, especially, embraces in fact, more in the greatly en- sures per unit area which clearly several orders of magnitude cover- hanced depth of field they offer. A 56 exceed the maximum permissible ing, for example, components in component is sharply depicted not

german research SPECIAL 2004 only in a certain plane, but is recog- with the help of the pincer device, Microscopic drops of adhesive nisable over the entire extent of the but in most cases, they also have to were placed on a glass surface in field. Hence the images have an al- be joined together. Very often, elec- a regular pattern of dots. They are only 1.5 billionths of a litre in volume. most three-dimensional plasticity. trical, optical and mechanical com- Due to the heavy investment in- ponents made of a diversity of ma- volved, this monitoring system terials have to be combined into an plays a negligible role in industrial overall system. This presents a production processes, but for re- great challenge. Amongst the search purposes SEM offers un- processes under study are the weld- can be employed for electron-beam beatable oppor- ing of plastics, welding with a small beam diame- tunities for ob- plastic assembly ter and high output density. In addi- serving process- Electrical, injection mould- tion to being used for microwelding, es during micro- ing, microsolder- the SEM also offers the advantage assembly opera- optical and mechanical ing, microelec- of affording an observation facility. tions. A further components tron-beam weld- Despite the fact that simultaneous approach to ac- are combined into ing, and laser- observation and welding are not quiring a cost-ef- beam welding possible, it nevertheless enables the fective means of an overall system and soldering. A positioning of the joined compo- observation lies further joining nents to be checked and the joints in integrating an technique em- to be displayed and measured once endoscope into the pincers. This braces the use of adhesives. Apart the welding process has been com- makes it possible to look directly purely mechanical fixing, glues pleted. between the arms of the pincers. often perform additional functions, The first prototype with this modifi- such as sealing against liquids or Prof. Ulrich Dilthey cation has already been made. Fur- gases. Microelectron-beam weld- Dr.-Ing. Annette Brandenburg thermore, the integration of a laser ing is a recently developed joining RWTH Aachen lens will enable the components, method. Within the framework of Prof. Manfred Weck once positioned, to be soldered on our research mandate we have Dipl.-Ing. Bernd Petersen the spot. The tiny components have modified a normal scanning elec- Fraunhofer-Institut not only to be moved and positioned tron microscope in such a way that it Produktionstechnologie, Aachen 57

german research SPECIAL 2004 The event reputed to have contributed most to escalating the conflict in Chiapas has also left its mark on the fine arts: This contemporary lithograph by José Martínez shows the murder of the priest from Chamula and his escort by the Tzotzil Indians, who believed their creed to be under threat.

58 Arts and Humanities

On the Battlefield of Chiapas

In Mexico, the history of a conflict between ethnic Indians and ethnic Mexicans has survived in the memories of successive generations, having been handed down solely by word of mouth

59 t began with the worship of effi- Our investigation was not only of their new “Santo”, effigies of gies of new gods, and ended in a concerned with discovering the In- gods similar to the holy statues Iviolent uprising and a host of dian viewpoints and comparing found in churches. Where the high- dead. This was the situation at the them with contemporary Ladino lands merged into the lowlands, in beginning of the 18th and around documentary sources. We also other words, in an ideal geographi- the middle of the 19th centuries, aimed to discover the precise course cal location, a flourishing Indian when the Indians in Chiapas rose of this religious revitalisation move- market grew up, as a result of which against repression by the Church ment and to test basic premises of trading in the highland town of San and state. When the interest of Cristóbal was brought almost to ethnologists becomes focussed a complete standstill. In the on such distant events the in- course of this development, evitable problem arises that mounted terror commandos sal- documents relating to these lied out of the town to destroy events are either incomplete or the market, and priests de- no longer existent. So how can stroyed the holy shrine, which evidence of the true motives was always subsequently re- underlying the conflicts in those built. When the priest from days be collected? The point of Chamula destroyed it for the view of the Indians can only be third time he was killed by the discovered from what has been enraged Indians. This was fol- handed down by word of lowed by three days of counter- mouth. What in Europe would terror. The Indians now en- have been a hopeless under- gaged in the indiscriminate taking – just think, for example, slaughter of innocent Ladinos. of trying to discover new as- More than a hundred victims pects of the Franco-Prussian were counted, mostly women war of 1870–71 from purely oral and children. records after a time-lapse of A few days later, near San over 100 years – was, under the Cristóbal, the Indians and the special conditions prevailing in Ladinos clashed once again – the highlands of the Chiapas, this time there were over 80 rewarded with surprising suc- dead on each side, but no clear cess. victor. A week after this, the Not even the political up- government troops, now rein- heavals of the Mexican Revolu- forced, inflicted a crushing de- tion (1910 to 1917) had any im- feat on the Indians. The rebels pact on the local mountain vil- fled, and although they tried to lages and their broadly scat- regroup in various places in the tered farmsteads. No political mountains, and to resume the events of any note have taken place Narrator from San Andrés, head of a school practice of their religious cult, the in this region since 1870. And since for Indian women weavers, in a self-made government forces, having pursued neither the few schools nor the blouse. Right: Narrator from the parish of them for over a year, nevertheless San Pablo Chalchihuitán. This specialist in media have exerted any manipulat- oral history retails reports on local history, finally triumphed in the autumn of ing effect, the events of those distant myths, prayers and hunting episodes. 1870. days have remained in vivid local Very different interpretations of memory. Between 1970 and 1998, the nature of these events have visiting diverse Indian communi- current narrative research. Has this been expressed. Some people ties, we succeeded in recording 22 picture of the past just been con- talked about an inter-ethnic conflict reports, narrated in “tzotzil”, the structed on the basis of the narra- fired by the centuries-old hate felt Maya-language spoken by the Indi- tor’s current situation? Are the nar- by the Indians against the Ladinos, ans, and a further two from Spanish- rators relating their tales truly in ac- others called the dispute simply a speaking Mexicans (Ladinos). Some cordance with their social and eth- barbarian attack on a superior cul- of the more elderly narrators had nic identities? This question, espe- ture. Some historians later interpret- still acquired their knowledge from cially, can be investigated through ed the conflict as a class struggle, a eye-witnesses, and the younger the medium of an inter-ethnic con- struggle for a paradisaic early form ones had relied mostly on their flict such as experienced by the of communism – however, no evi- grandfathers or grandmothers. Tzotzil Indians of Chamula. dence from original sources was Most of these reports were compiled It began at the end of 1867 in Tza- ever produced in support of this between 1970 and 1982, i.e. after a jalhemel, a remote hamlet in the postulation. lapse of 100 to 112 years since the parish of Chamula. The local popu- Contemporary documentary 60 events. lace held regular festivals in honour sources had already made it clear

german research SPECIAL 2004 that at the beginning of the revolt a out the devotees of the cult – a fact newspaper articles of those days. religious movement was involved. which effectively confutes the long- Worthy of note is the way in which From the numerous oral traditions, held vision of a widespread Indian today’s Ladinos assess the person of however, we now know that the re- revolt. Galindo. This Ladino had gone over ligious motivation regained the One motive has excited special to the devotees of the cult in the upper hand after the military de- interest in the Chamula revolt, and Chamula area three weeks prior to feats in June and July 1869, and was has even been explored in detail in the outbreak of hostilities. In con- clearly dominant in the final phase. fictional literature: the macabre cru- temporary reports he is described as At the start, effigies of gods being the leader of the rebels, a were worshipped whose names blood-thirsty killer, who had had been derived from Catholic been branded as a traitor to his saints, then Indians had parad- race. After the massacres in the ed as these gods, and later on, hinterland he did indeed ap- only the new gods were men- pear at the head of the Indian tioned. In their last stronghold masses before San Cristóbal. in the remote mountain region However, he refrained from at- of San Pablo, the number of tacking, and instead requested these gods had doubled to negotiations to secure the re- eight. At their head was the god lease of the Indian leader Pedro Sanmateo, personified by the Díaz Cuscat, who was impris- founder of the new religion, the oned at that time. After lengthy Chamula Indian Pedro Díaz deliberations, Galindo himself Cuscat. entered the town under a per- sonal safe conduct granted by hereas the contempo- the authorities of San Cristóbal. rary literature is almost By doing this, Galindo prevent- Wexclusively concerned ed an attack by the Indians, but with battles and the numbers of a few days later the governor of killed and wounded, the narra- Chiapas rescinded this safe tives of the Indians furnish a conduct and Galindo was sum- vivid picture of the religious cult marily shot. No mention at all is itself. In no way did the self-ap- made of Galindo in Indian nar- pointed gods appear in full ratives, raising doubts as to pomp and splendour in an at- his role as a leader. In contrast tempt to bridge the gap to the to this, in Ladino records, he is ancient Indian forms. They the leading character. Quite were much more orientated to- unlike the negative picture of wards the festive costumes of him painted in contemporary rich Ladinos. As reports from sources, he is portrayed here as various districts relate, Sanmateo cifixion of a young Indian on Good a tragic figure, and as the victim of was obsessed by the idea of using Friday of the year 1868. The aim of squalid political intrigues. In this ritual dances to prevent the ap- this action was purported to have case, the Ladino version is obviously proach of the soldiers. But as they been the acquisition of a Christ “of a true reflection of the actual events. still appeared and pressed home their own”. However, the veracity of From the way all this has been their attacks, serious doubts arose as this has also now been placed in narrated, which is also typical of the to the legitimacy of these new gods. great doubt by the traditional narra- Indians, it may be deduced that the After their expulsion from the ter- tives. It is noticeable that not a sin- current political situation and the ritory of the Chamula, the fleeing gle narrative – either from the Indi- ethnic origins of the narrators have rebels found themselves on the ter- ans or the Ladinos – mentions the little influence on the content of ritories of diverse other Tzotzil com- crucifixion, whereas several do in- their narratives. Only in exceptional munities, and had to find some deed report on the murder of the cases was any form of tendentious- mode of cohabitation with the in- priest, which occurred within the ness detectable. digenous Indians. It is clear from same chronological and geographi- the narratives handed down by the cal framework. Inspection of the Prof. Ulrich Köhler affected communities that they documentary sources revealed that Universität Freiburg were unable to do this. The new ar- only one single author had reported rivals acted as lords in the territories on the crucifixion, and that was All these narratives and detailed analyses have been published in Ulrich Köhler, Der of their hosts and became a burden twenty years after the event, more- Chamula-Aufstand in Chiapas, Mexiko, aus on the local economies. As a result, over, there is not the slightest evi- der Sicht heutiger Indianer und Ladinos. the native populace appealed to the dence of a crucifixion to be found in Münster 1999. The book contains lengthy government to send troops to drive any of the numerous anti-Indian summaries in Tzotzil, Spanish and English. 61

german research SPECIAL 2004 Life Sciences

The Refuge under the Bark Nearly one quarter of Australia’s insect species live under the bark of eucalyptus trees. These fissured trees afford carabids in particular protection from the sun, fire and rapacious enemies. Carabids have adapted extremely well to life under the bark

62 ustralia has always stimulat- quently, most of its inhabitants were has fallen. Some of the beetles have ed the interest of biologists, adapted to cool climatic conditions. switched to the trees for shelter from Afor the flora and fauna of this In the course of the continental drift, the blazing sun. As a rule, these island differ considerably from however, it moved northwards, trees are eucalypti, the prevailing those otherwise familiar to us. For where it became increasingly arid. group of trees in the deciduous 40 million years, over almost the en- The overall climate became forests, savannahs and tree steppes tire geological era which began warmer, forcing the animal world to of Australia, where they colonise around 67 million years ago and adapt to these drier conditions. At every mildly humid habitat in large lasted some 60 million years, Aus- all events, the carabids adapted numbers, stamping their own tralia lay isolated. This continent is well. This is a group of insects num- unique mark on it. Even in arid like a raft which tore free and only bering just under 35,000 species areas, these adaptable plants are to touched land again after a very world-wide, whose members be found growing along wa- lengthy passage of time. Many of are mostly carnivorous, and tercourses. the creatures involved in this jour- good, fast, runners. In tem- Eucalypti are a very richly ney perished during the voyage, perate latitudes the majority endowed group of trees, others were able to make their way of these animals are encompassing not only gi- and multiply. Hence, although con- ground-dwellers, in the gantic, but also small, temporary Australian flora and tropics, in contrast, many shrub-like representa- fauna are lacking in major divisions, live on leaves or the tives. They exhibit a in many of the groups large num- trunks of trees. multitude of different bers of for the most part closely re- Interestingly enough, growth, leaf and bark lated species have developed. although known in forms. A considerable At the beginning of the Tertiary, Germany as “run- portion of the euca- Australia lay far to the south of the ning beetles”, just in lypti possesses a bark lower half of the southern hemi- Australia this name is which is regularly shed sphere, at the eastern edge of inappropriate as the in long strips from the today’s Antarctic continent. Conse- proportion of these trunk, leaving crevices species which actually in the wood into which runs around the surface a unique animal world of the earth there is has moved. Under the small compared with bark of a single tree other continents. Almost tens, or even hundreds, three quarters of the sur- of thousands of animals are face of Australia lies under to be found, extending in threat of water shortage, and the range from tiny springtails to repre- carabid’s chances of surviving this sentatives of nearly every group of growing aridity are small. Either insect, isopods, millipedes, spiders, they have withdrawn to the banks and even small vertebrates. These of rivers and lakes, where they can form food chains with numerous still find a certain amount of humidi- links. How has this rich fund of ty, or they dwell – better protected fauna developed under the euca- from heat and aridity – in the soil, lyptus bark? There has quite evi- from whence they make their way dently been an interplay between to the surface at night or after rain supply and demand for, despite the fact that Australia’s arid areas offer better conditions for survival than those in other continents, survival nevertheless presents problems. In particular, the eucalyptus forests appear to be more accommodating

Left-hand page: Eucalypti like this gnarled river eucalyptus can host over 100,000 insects. Beetles of the most diverse species dwell under the bark. There (left) long- legged, sap-sucking tree bugs are also moving in. Above: A carabid, Philophloeus eucalypti, displaying its characteristic colour pattern. 63

german research SPECIAL 2004 than they actually are, for which lowers the internal temperature. three main factors are probably re- Under these harsh conditions, nu- sponsible: the growth form of the merous animals have resorted to crowns, the shape and position of this unique refuge. Many only the leaves, and the high frequency emerge at night to hunt on the sur- of bush fires. face of the bark. Others leave the Most eucalypti have windswept, trees under the protection of dark- open crowns highly permeable to ness and move to the ground, and light. As, moreover, their leaves are many pass their whole lives under mostly elongated in shape and ver- the bark. It is postulated that almost tically suspended, reflecting the one quarter of all the known species light from their glossy, leathery sur- of insects in Australia use the bark faces, the soil under the eucalypti is of the eucalyptus tree either as a open to abundant radiation. So it is refuge or a habitat, as do the cara- not without good reason that people bids, too. Amongst the latter, the talk about the “shadeless forests” of proportion living under the bark is Australia. Even in the densest especially high – probably over woodland, soil animals have 700 “subcorticole” species exist. to contend with very high These are distributed amongst temperatures on the surprisingly few species-rich ground. The third factor genera. It would appear are the frequent bush that in the case of the fires. These regularly de- carabids only a few sur- stroy the dead leaves and vived the long passage undergrowth, thus en- through the Tertiary, but dangering any ground- that they then colonised dwellers unable to es- their new habitats with- cape in time. out delay, and have Animals on the since developed an ground and in the de- amazing abundance tritus strewn around of species. This is the floors of eucalyp- not surprising, bear- tus forests thus have a ing in mind the rich difficult time. They can diversity of fauna in- only counter the high habiting the crevices, temperatures and fre- which offer carnivo- quent bush fires in two rous insects a host of ways: either by digging possibilities. in, or by colonising the However, the immigra- innumerable crevices of- tion of these carabids into fered by the eucalypti. this habitat cannot have The bark of the eucalyptus tree taken place so very recently, as affords its inhabitants not only pro- some astounding forms of adapta- tection from their enemies, but also tion have occurred in the process. astonishingly good thermal insula- That the bodies of the majority of tion. Measurements have revealed these beetles are elongated and that the temperature gradient be- very flattened is not difficult to un- tween the outer and inner sides of derstand, nor that the soles of their larger pieces of bark can be 25 de- feet are equipped with thick brush- grees Celsius or more. Hence bush es to improve their hold on the fires, which normally pass through the forests at a fair speed, can scarcely affect the crevice dwellers. Only a more prolonged and inten- Right: The bark of many eucalypti is sive conflagration can drive the regularly shed in long strips. To protect temperature under the bark to a themselves from the sun and predatory dangerous height. Even where the enemies, carabids, a group of insects external temperature is extremely embracing an estimated 35,000 species, find refuge in a habitat beneath the bark. high, small water droplets under the The carabid Amblytelus curtus, here in its bark create a relatively high degree warning coloration, also forms part of this 64 of atmospheric humidity, which community.

german research SPECIAL 2004 Regular bush fires on the Australian continent and “shadeless forests” in the tropical tree savannah (left) make life difficult for beetles on the ground. Examination of the bark fauna (below left) using a simple umbrella to catch the beetles falling out when the bark is stripped off.

clear whether these bright colour schemes might not exist to feign an unpleasant taste or toxicity. One sub-family of the carabids has taken adaptation to the subcor- ticole way of life so far that its mem- bers can scarcely be recognised, even by carabid specialists. The group of the Pseudomorphinae, es- pecially, have developed extremely original forms in the course of their smooth surface of the trunk. But evolution: the head has become in- what is the significance of the con- creasingly recessed under the spicuously dark colour pattern on a pronotum (dorsal plate), and the yellow or bright red background? In wing-covers so broadened that they view of their way of life, these bee- cover the legs. The feelers and legs tles are classified as nocturnal, in can be folded into grooves, and the which case conspicuous warning legs have become so foreshortened colours are not actually necessary. and broadened that they really bear The entire complex of camou- no similarity at all any more to those flage, warning and mimicry has yet of normal carabids. With this power- to be studied. However, one theory ful physique, these beetles have – not yet confirmed by observation adapted themselves marvellously to or experiment – holds that these their subcorticole way of life. At the colour schemes serve as protection same time, it protects them from the against birds specialised in preying ravages of redoubtable ants and ter- on bark animals. The so-called tree mites. creepers, in particular, regularly use their beaks to lever off pieces of Martin Baehr bark and so gain access to the Zoologische Staatssammlung insects underneath. It is still not München 65

german research SPECIAL 2004 66 Natural Sciences A Treasury in Sibiria

35 million years ago a cosmic projectile struck the earth in North-western Siberia and left a crater over three times the size of Luxembourg – Popigai. UNESCO had good grounds for designating this crater as part of the world’s geological heritage rom the results of ground-based remote sensing and space mis- Fsions we know that the surfaces of nearly every solid planetary body exhibit a multitude of craters due to the impact of asteroids and comets. The impact of these projectiles at a velocity of many kilometres per sec- ond causes immediate release of massive amounts of energy. This creates a crater, causes the ejection of large amounts of rock, and in- duces unique, irreversible changes in rocks and minerals (shock-meta- morphism). An impressive example of such an impact was that of comet Above: The remnants of the main camp Shoemaker-Levi 9 on Jupiter in July contain still valuable old drill cores. 1994. Left: Micrograph of a rock containing a diamond grain about 0.15 mm Approximately 160 impact craters in size, which was generated from and just under 20 sediment horizons graphite at 350,000 times with ejecta material are known to atmospheric pressure. date on Earth. Most craters are lo- Right: Fresh tracks – wolves follow cated on continental shields. Vrede- the geologists as an invisible fort, in South Africa, with a diameter escort during the fieldwork. of about 250 kilometres and an age of 2,023 million years, is the largest and oldest known terrestrial impact million years old. This distribution structure. About 60 per cent of the in space and time reflects the dy- terrestrial craters, however, are con- namic nature of the Earth: erosion 68 siderably younger, less than 200 and plate-tectonic processes erase

german research SPECIAL 2004 the traces of these impacts, remov- The analysis of terrestrial craters aged only 35 million years, it is the ing mostly old and small craters. also has a “planetary” dimension. only complex impact structure on Other structures, such as the Chicx- While the morphology of impact Earth that shows scarcely any traces ulub crater on the Yucatan Peninsu- structures on other bodies in our of erosion, and is thus completely la in Mexico, which is approximate- solar system is known in detail from preserved. Complex impact struc- ly 180 km in size, are buried under spacecrafts and Earth-based obser- tures differ from the much smaller, thick sequences of younger sedi- vations, the sub-surface structure simple or bowl-shaped craters ments and can only be detected by and the spatial distribution of rock through the presence of ring-walls geophysical methods. Today, the formations – the third dimension – and annular troughs, and in certain search for geo- can only be un- cases, a central peak of uplifted logical evidence derstood if re- rocks. Popigai, approximately three of impact events The Popigai crater – sults of ground- times the size of Luxembourg, con- is primarily based research tains fantastic outcrops of typical linked to the at 35 million years old, on terrestrial impact rocks. Some of these – the question of fairly young – has craters are taken “impact melt rocks” – originated whether impacts scarcely been altered into account. within a few seconds from material and their short- Where such a that was heated to well above 2,000 and long-term by erosion structure is well degrees Celsius after release from effects have in- exposed it stands the high pressure of the shock- fluenced the for- as a three-di- wave. Other rocks are multi- mation and evolution of the atmos- mensional model that is accessible phere and biosphere. For example, on foot. Fieldwork, geophysical in- sediments deposited worldwide 65 vestigations, drilling into the base- million years ago bear traces of the ment and multi-disciplinary labora- Reaching the outcrops along Chicxulub impact; these findings tory studies of rock samples furnish the banks of the Rassokha River demonstrate the causal link be- data necessary for setting up a gen- was only possible by means of rubber boats. tween this impact event and the erally valid model for the formation The scientists collected over sudden mass extinction at the tran- of craters. Amongst the terrestrial 200 kilograms of rock samples sition from the Cretaceous to the impact structures, Popigai, in North- in Popigai – an immense reservoir Tertiary period (K-T boundary). western Siberia, is outstanding: for future investigations, too.

69 coloured breccias consisting of a va- Members of the expedition studying riety of crushed rock fragments from veins and pockets of black rock debris different sources in the crater. The in a large limestone block. Right: During ejection, this “gneiss bomb” size of these clasts ranges from was coated with impact melt in the small mineral grains to several tens vapour plume above the growing of metres – the mixing and crushing impact crater. of the material give an idea of the giant forces which are released dur- ing an impact process. The compo- realised that at least part of the dia- nents of these breccias are mixed to- monds known since the last century gether during ejection. In Popigai, to occur in specific meteorites had the impact rocks form steep cliffs evidently been generated in violent along the banks of the rivers, dis- collisions within our solar system. In playing a palette of colours from the early seventies, a team of Soviet browns and ochre-coloured pastel geologists then discovered the first shades to deep blue, depending on terrestrial impact diamonds, initially 2,000 million years old. These dia- the incident light. in a placer, and later in the Popigai monds are not suited for cutting, yet area, which was later identified as their hardness slightly exceeds that ut Popigai’s outstanding rank an impact crater. Russian scientists of normal diamonds – a property of amongst terrestrial craters re- subsequently succeeded in identify- great interest to industry (drilling, Bsults not only from these excel- ing impact diamonds in numerous grinding and polishing). Between lent outcrops and their pristine state craters in the former USSR, and also 1970 and 1986, intense geological of preservation, but also from the in the Nördlinger Ries in Germany. research was conducted in Popigai, presence of an extraordinary variety The diamonds, whose colours range involving mapping, drilling some of diamonds. That diamond forms in from transparent, to white, yellow, 500 exploration wells, and trans- impacts has been known since the grey and black, originated by trans- porting many tons of rock to re- sixties, when diamond was synthe- formation from graphite flakes and search facilities in the European sised from graphite for the first time grains. The graphite was a mineral part of the USSR. The extreme cli- using shock-wave experiments. component of the crystalline rocks matic and geographical conditions 70 Based on this discovery, it was soon in the crater target, which were over in North-western Siberia, where

german research SPECIAL 2004 Over 140 metres high, spectacularly dition got permission to visit Popi- steep cliffs string along the banks of the gai. A few helicopter hours away Rassokha River. Individual rock fragments from Khatanga, the nearest base can reach the size of a house. Above, left: Two eagle chicks in their nest high above manned continually all the year the Rassokha River. Left: The rock “bombs” round, the scientists constructed ejected from deep target levels during the their primitive camp on a gravel ter- impact, are now a component of the race on the banks of the Rassokha breccias, which also contain finer-grained River. Within days, floodwater material. turned the river into a raging torrent which, although posing a threat to the tents, nevertheless uncovered temperatures down to minus 50 de- the skull of a mammoth in a sand- grees Celsius occur, presented an bank. exceptional challenge. The investi- In view of its extreme location, the gations revealed that Popigai, with Popigai structure, which UNESCO a diamond content of 5 carats/ton of has declared to be part of the rock, represents a giant, yet eco- world's geological heritage, will re- nomically inexploitable diamond main a hidden treasure, despite its deposit. Nevertheless, it was a wealth of diamonds. – Our sample strategic resource for the Soviet material, however, forms a sheer in- Union as the crater contains many exhaustible stock for current and fu- more diamonds than all the world’s ture scientific studies. other diamond deposits put togeth- er. Hence all the results of these ge- Priv.-Doz. Dr. Alexander Deutsch ological investigations remained Universität Münster under lock and key. Popigai was Priv.- Doz. Dr. Falko Langenhorst only accessible to Soviet scientists, Universität Bayreuth and is still a prohibited area. It was Prof. Victor L. Masaitis only in 1997 that a small German– Karpinsky Geological Institute, Canadian–Russian scientific expe- St. Petersburg, Russia 71

german research SPECIAL 2004 Life Sciences

The Loneliness of Island Life

n his classical novel from the early habitats. Analogous to the advan- ease or seed predators. The loss of a 18th century, Daniel Defoe tages and disadvantages of the iso- beneficial interaction might occur, Idescribes the life of Robinson lation which Robinson Crusoe expe- on the other hand, when pollinators Crusoe, who was shipwrecked on rienced, the absence of partners for or seed distributors have disap- an uninhabited island, where he organisms on an island can have peared from the scene. subsequently spent the next 28 both beneficial and prejudicial con- It has long been known that small years. One day, cannibals appeared sequences. In the absence of natural and isolated habitats support few from the mainland, and it was at this antagonists no prejudicial interac- plant and animal species. As habi- juncture that he realised that inter- tions will occur. For example, a rare tats increase in size and become less human contacts are not necessarily species of butterfly which has lost a isolated their biodiversity expands a good thing, and that isolation can predator through the drastic reduc- because the immigration rate has also have its advantages. tion in its habitat will enjoy a lower become greater and the extinction This inherent conflict of island life mortality rate, and a greatly dimin- rate has fallen. Moreover, larger also becomes apparent on inspec- ished threat to its existence. In a habitats offer greater diversity and tion of the impoverished communi- similar manner, plants can profit can provide more niches than small- 72 ties of the flora and fauna in island from the absence of exposure to dis- er ones. In recent years, this concept

german research SPECIAL 2004 The continuing reduction and fragmentation of habitats is not only affecting biodiversity, but has also led to the loss of important ecosystem functions

has not only been applied to oceanic loss of species on islands and the field by studying the links between islands, but also to island habitats in drop in interactions. From the point the loss of natural antagonists and cultivated country. For through of view of nature protection there is the mortality rate of herbivorous in- human intervention, and especially a specific interest in documenting sects on the one hand, and those be- through the dramatic intensification the impacts on ecological functions, tween the loss of flower-pollinators of farming which has taken place in in other words on the interplay be- recent decades, many natural habi- tween the organisms themselves or tats, such as oligotrophic grassland between the organisms and their or stone-fruit meadows, have tend- inanimate environment. The ques- ed to disappear. In many places, tion arises as to whether there is any Even a plot of land of the size of this these habitats are now only present connection between loss of species stone fruit meadow functions amongst in the form of tiny, isolated residues, due to habitat fragmentation and tilled fields as an island habitat. so that their communities exhibit an the impairment of the functionality Left: Bumble Bees, Skippers, Long-horn Beetles and Shield Bugs visit the blooms isolation similar to that found on of ecosystems. In two DFG-support- of a thistle. Solitary bees and bumble “real” islands. There is now grow- ed projects we have been address- bees play an outstanding role in the ing evidence of a link between the ing this topical and little researched pollination and seed set of most plants. 73

german research SPECIAL 2004 and the reproductive success of plants on the other. The consequences of habitat fragmentation with respect to biodi- versity and interactions were analysed experimentally. Island habitats for clover insects were cre- ated by placing pots of red clover on the edges of cornfields. These is- lands, lying in cleared agricultural landscapes, were much more suc- cessfully colonised by herbivorous insects from the group of weevils (beetles), than by their natural antagonists, the parasitic wasps. However, not only was the number of parasitic wasp species on these islands smaller than that of the her- bivores, but infestation with these parasitoids was also reduced: on isolated islands 500 metres away from the nearest field with red clover, it was only one third of what had been expected. This reduced mortality to such a low level that it was no longer possible to assume any successful control of these her- bivores by their antagonists. This experiment revealed that the isola- tion of a habitat has a greater impact on the antagonists than on their hosts or prey. cases, not only was there a reduc- loss of fitness of the oil radish and The high extinction rate of the tion in biodiversity, but also a much mustard. Thus, even at a distance of parasitic wasps on the habitat reduced mortality rate amongst the 250 metres from the nearest olig- islands, however, was not solely at- herbivores. otrophic grassland, the number of tributable to their “higher” position seeds produced by the oil radish in the food chain. Other aspects armland has been exhibiting was halved, and those of the mus- characteristic of species under ever-decreasing numbers of tard at a distance of 1,000 metres. threat of extinction were also in- Fbees, and the pollination of wild Working with potted plants elimi- volved. The parasitic wasps exhibit- and cultivated plants can no longer nated alternative hypotheses ed a lower frequency and much be taken for granted. This supposi- regarding the causes of this island greater variation in population den- tion was checked using habitat is- effect (genetic erosion, lack of nutri- sity. Species of greater rarity or lands comprising potted oil radish ents, population size): every island more marked population fluctu- and wild mustard. Both plants are had genetically identical plants, the ation are regarded as being particu- annuals, which means that their re- same supplies of nutrients and the larly endangered. The results ob- production is dependent on seed identical number of plants. Similar- tained from these landscape islands production, and both are dependent ly to the insect communities on red were supplemented by a compari- on cross-fertilisation by insects. The clover, this experiment in flower son between large and small stone- habitat islands were so positioned in ecology showed that there can be a fruit meadows. A similar picture the cleared agricultural landscape connection between the loss of emerged. The red clover popula- around Göttingen that they were up species and the loss of an important tions on small stone-fruit islands to a thousand metres from the near- ecosystem function. Since over 80 exhibited almost as many species of est calcicolous oligotrophic grass- per cent of all cultivated plants, and herbivorous insects, but far less land (with its numerous species of over 90 per cent of all wild plants, parasitoid species. Here, too, the bees). As expected, the number of are dependent upon cross pollina- mortality rate induced by the para- visits paid by bees to the flowers tion, this increasing loss of wild bees sitoids was extremely reduced. The dropped significantly (but not those and other pollinators presents a results showed that isolation (of the by flies or other insects). The loss of great potential threat. “artificial” red clover islands) and bee species was linked to the reduc- Arable fields can also be regard- contraction (of the stone-fruit mead- tion in the seed potential, in other ed as islands. Each year they are 74 ows) led to similar effects. In both words, with the reproductive loss or cleared after the harvest and

german research SPECIAL 2004 colonised anew. Correspondingly, damage. Its predator is a specialised habitat. In a DFG-supported pro- great biodiversity and pronounced parasitic wasp. A comparative study ject we followed up the idea that interactions can only be expected if of field-margin strips revealed that these parasitic wasps, which can there is a close connection of annual infestation by parasitic wasps was attack the flower rape beetle so crops combined with long-term promoted by old, but not by young successfully, play a much greater habitats (fringe biotopes or fallow strips. The mortality rate due to par- role in diverse, complex landscapes land). This project at the Göttinger asitic wasps directly along the edge than in monotonous, simple ones Forschungs- und Studienzentrum of a field was in both cases high, but which have been cleared of almost für Landwirtschaft und Umwelt (Re- only in the case of the old strips, all perennial vegetation. Our data search and Study Centre for Agri- did these parasitic wasps move confirm the hypothesis that the culture and Environment in Göttin- out into the field and so produce mortality rate caused by parasitic gen) was designed to investigate similar mortality rates within the wasps is higher, and the damage to whether field margin strips and field itself. It was discovered that rape considerably lower, when the fallow placed alongside rape fields this dissemination of the large an- rape field lies in complex farmland. would serve to promote the natural tagonist communities into the pe- These examples show that the antagonists of the blossom rape ripheral biotopes trebled the mor- increasing diminution and isolation beetle. By eating the buds, the blos- tality rate. Yet old field margin of habitats is causing the extinction som rape beetle prevents pod form- strips are not the non plus ultra for of many species. It is an important ing and thus occasions considerable the promotion of useful insects. If, argument for nature protection that instead of old strips, old fallow bor- the loss of diversity is frequently ders the winter rape field, then the linked to the loss of important func- infestation with parasitoids is even tions of the ecosystem, such as pest higher. The results show that the control or plant pollination. An experimental island of red clover at significance of natural antagonists the edge of a cornfield. Below: Old strips increases with the age and size of Prof. Teja Tscharntke of arable land bordering a field of winter the adjacent natural habitats. Dr. Andreas Kruess rape (left) offer a habitat to the natural antagonists of the blossom rape beetle. Moreover, it became clear that the Dr. Ingolf Steffan-Dewenter Insects such as parasitic wasps reduce the mortality rate of this pest can be in- Dr. Carsten Thies numbers of pests. creased radically by altering its Universität Göttingen

75 A crown? A test crown! It is surrounded by thermocouples which measure the course of the temperature. The gauges touching the veneer are supported by a wire cage.

76 Natural Sciences

Each year ceramometallic dental restorations worth several hundred million euros are fabricated in Germany. However, during fabrication such restorations can be damaged by thermal stresses. Basic research is supporting the safe production of such porcelain- fused-to-metal systems In the Service of the Crown

eramometallic dental restora- peal, and outstanding resistance to tions (crowns, bridges, pros- wear. In recent years, in order to re- Ctheses) have been in routine duce costs, in addition to high gold- use in dental prosthetics now for content alloys, palladium-based about 35 years. But still, and espe- and non-precious alloys have also cially when dental technicians re- been employed. The CoCr-alloys, sort to a new alloy and/or ceramic, especially, provide markedly better cases always occur where spalla- rigidity than the classical precious tions or cracks appear in the ceram- alloys while offering comparable re- ic veneer, or where the metal-ce- sistance to oral corrosion. ramic bond between the veneer and When fabricating ceramometallic the metallic substrate is damaged restorations, an alloy frame (“sub- by shearing. This damage can take strate”), cast according to dental im- place either already during fabrica- pressions submitted by the dentist, tion of the restoration in the labora- is coated with ceramic material. tory, or when fitting it into the pa- Being a mixture of powder and liq- tient’s mouth, or after a short wear- uid, this is initially of a pasty consis- ing time. Since ceramometallic tency. The object is mounted onto a restorations worth several hundred special firing tray and heated to a million euros are produced each high temperature in a furnace. De- year in the Federal Republic alone, pending on the ceramic, the firing it is of national economic impor- temperature will vary between 850 tance to investigate the origin and and 900 °C. The restoration is subse- distribution of the thermal stresses quently cooled to room temperature responsible for this damage. according to a pre-programmed Ceramometallic dental restora- schedule, initially in the furnace, tions comprise an alloy frame onto and subsequently outside in the am- which a ceramic (“porcelain”) is sin- bient air. Due to the fact that the ce- tered. They thus combine the high ramic contracts during sintering, the rigidity of the alloy with the benefi- firing process normally has to be re- cial properties of ceramics: excel- peated several times. At the glass lent biocompatibility, unsurpassed (transition) temperature, which usu- and highly durable aesthetic ap- ally lies between 550 and 600 °C, 77

german research SPECIAL 2004 during cooling the ceramic changes to determine analytically or numeri- from the plastic-viscous into the cally the precise rate of heat loss to elastic-brittle state. Above the glass the ambient air. Consequently the temperature, the ceramic is suffi- surface temperature was measured ciently fluid to follow its own con- experimentally during the cooling traction without generating any process using thermocouples. With stress. Below the glass temperature, the given initial temperature distri- in contrast, thermal stresses develop bution in the complete crown, this in the ceramometallic system due to information permits unique compu- the differences in thermal expan- tation of both the temperature and sion behaviour between the ceram- the thermal stress distribution in- ic, now “hard”, and the alloy. Left to side the crown. themselves, the veneer and its sub- strate would no longer follow the same geometry, but now they are bonded together at the material in- terface. Consequently constraint stresses develop. In the case of “thermally incompatible” combina- tions critical thermal stresses can produce damage, either during fab-

In a first simulation, long-term cooling in the furnace was simulat- ed. At a homogeneous crown tem- perature of 600°C, and thus just slightly above the glass temperature of the ceramic (581.7°C), the lid of the furnace was opened and the crown extracted. Considerable tem- perature gradients (differences) im- mediately built up in the crown: the highest temperatures were all mea- sured on the substrate, the lowest at the surface of the veneer. This was During cooling, a test crown is exposed to because the ceramic is able to radi- high stresses. 26 seconds after opening the furnace the temperature gradients (left, ate its heat freely into the environ- showing full crown), and thus also the ment, whereas the surface elements transient thermal stresses, are at a in the hollow space of the frame are maximum (red: high values, blue: low subject to mutual radiation. More- values). They are first concentrated at the over, the surface of the veneer loses surface of the ceramic veneer (centre, more heat to the passing air by con- displaying only the ceramic veneer), but in the crown at room temperature at the vection than can a cavity such as the interface between frame and veneer interior of the substrate. (right, ceramic veneer only). The maximum temperature gra- dient between substrate and ceram- rication or, later, due to additional ic surface occurs approximately half load stresses arising in the course of Measurements of the time-tem- a minute after cooling has started. It cementing or mastication. perature relationships at particular can exceed 120 °C. Tensile thermal In a DFG-sponsored research pro- surface points were interpolated to stress, too, is at its maximum at this ject scientists investigated the gen- a steady temperature distribution time. Tensile stresses are detrimen- esis of thermal stresses in cer- over the surface of the crown. This tal to a brittle material like ceramic. amometallic crowns. Apart from the served as an input for a so-called Fi- In the critical case they can lead to differences in thermal expansion nite-Element (FE) model for calcu- cracks or spallations. On the other behaviour between the two materi- lating the stress distribution inside hand, the interior of the veneer is als, the locally distinct cooling rates the crown with respect to time and under compression, or at the most, in the crown are also of great impor- space. Linear thermoelastic materi- mild tensile stress. As cooling pro- tance. Due to the complexities of the al behaviour was assumed for both ceeds, the temperature in the crown 78 crown geometry it is not yet possible the alloy and the ceramic. equalises out, i.e. the temperature

german research SPECIAL 2004 gradients decrease, and the maxi- for by long-term (slow) cooling. The be reconstructed. Surprisingly, the mum tensile stresses migrate from residual stresses in the veneer are experiments showed that the maxi- the surface of the ceramic into the uniquely determined by the glass mum transient thermal stresses bond interface with the alloy. The temperature of the ceramic, the ex- were also critically dependent on stress distribution “frozen” into the pansion behaviour, and the stiffness the interstice between the crown crown after fabrication, is called its of the two partner materials. The and its firing tray. residual stress state. transient thermal stresses, in con- Hitherto, the simplified case had However, of interest – and hither- trast, can be manipulated by the been simulated whereby the veneer to, most likely, unknown – is the fact cooling process: for example, if the is sintered onto the alloy frame in a that the magnitude of the so-called furnace is opened only at the tem- single firing process. The scientists transient thermal stresses, i.e. those perature of 450 °C – and thus well at Karlsruhe University are current- occurring during the cooling phase, below the glass temperature of the ly studying the more realistic firing can clearly exceed that of the final ceramic – they will be reduced by process in several steps. This is en- residual stresses. around one third. abling them to take due account of This can produce In a dental labo- the change in the ceramic’s coeffi- cracking or Model crowns show that ratory, however, cient of thermal expansion in rela- spalling, even where speedy tion to the number of firing process- during the cool- the thermal expansion fabrication of ce- es. After all, these simulations are ing process. properties of the ramometallic designed to furnish both dental Tests on model partner materials must products is the technicians and dentists with rules crowns which sine qua non, the for the safe fabrication of cer- were geometri- be compatible temperature at amometallic restorations. cally identical the opening of but made of dif- the furnace, due Dr. Jürgen Lenz ferent substrate alloys, revealed to the correspondingly longer dura- Dr.-Ing. Matthias Thies that thermal stresses decrease with tion of use, cannot be reduced at Prof. Dr.-Ing. Karl Schweizerhof decreasing rigidity of the alloy. Al- will. Universität Karlsruhe (TH) loys of high gold-content will re- It is a well-known fact that the duce the indicated stresses by maximum stresses present in the around 35 per cent. Hence, when bond interface of the cooled crown using non-precious metals great are critically dependent on the local After firing, fine cracks have appeared in care must be taken to ensure that no radius of curvature. Hence the den- the veneer of a bridge. Studies showed that excessive deviation in the coefficient tal technician is well advised to fabrication purposes, not only must the of thermal expansion of the ceramic round off the surface of the sub- “thermal compatibility” of the materials which have been used and the firing and and its substrate exists. With the strate. The dentist can also make a cooling processes be taken into account, majority of ceramics this difference useful contribution to this by an ap- but also the curvature of the surface of from the alloy can be compensated propriate preparation of the tooth to the alloy frame.

79 Engineering Sciences How a Town Can be Created in a Test Tube

In the computer scientists breed houses, villages and whole urban districts to check the interactions between buildings and their environs – a vital aid to planners and architects he creation of architecture is a contain a hierarchical road network, The DFG-sponsored research process subject to numerous and other times they show a com- project “Media-experimental De- T influences. Plans drawn up by plete estate depicting the individual sign in Architecture and Urban De- architects and urban planners are houses down to the last detail. De- sign” is addressing the creative use extracts related to given scales grees of detail not embraced by the of computers in architecture, and is whereby, depending on the select- given scales are not included in the examining the processes of growth ed or prescribed degree of accuracy, architects overall plans. of urban structures. The aim is to abstractions of the desired and This is particularly evident with identify the apparently unplannable planned reality are drawn, thus cre- historical urban structures which processes of urban growth, and to ating blurs. For a given degree of have evolved over the centuries. express them in terms of algorithms detail, external influences such as The interrelationship between (recurring processes of computa- topography, existing buildings, these conglomerates are so complex tion). These laws of growth can be green areas and geographical orien- that it is difficult to discern any laws applied in a virtual-reality environ- tation may be included in the overall of growth. The growth of the urban ment, thus enabling this phenome- design in exactly the same way as population is similar in form and non to be simulated on the comput- architectural data, the desired den- shape to that found in animate and er. Using this technique it is possible sity of building, or spatial distribu- inanimate nature, so that aerial pho- to proceed beyond three-dimen- tions. Sometimes the designs simply tographs of these settlements bring sional visualisation and, by pro- to mind colonisation by plant popu- gramming the laws, standards and lations or cell formations. legal acts of a virtual world, to model the development of urban structures and to observe their be- haviour. In this way, it is possible to behaviour” is a natural phenome- types of architecture has already “breed” towns as in a test tube. One non copied from the behaviour of been studied by Prof. Frei Otto, the element of current research is, in flocks of birds and swarms of in- designer of the roof of the Olympic fact, to achieve the, so to speak, evo- sects. Once the prescribed condi- stadium in Munich, who based his lutionary and genetic “cross-breed- tions have been met, the generator architectural forms on examples ing” of urban development modules produces a building. Because these from nature. and their algorithms; in view of the generators are all interactive this The structures of villages create similarity between organic struc- comparatively simple programming an organic, unintelligible and com- tures and growth in urban develop- results in very plex effect and ment this idea would appear to be harmonious and are less subject an obvious step. natural paths of A communal “social” to formal laws A limited number of selected pa- movement which than towns or rameters, including the growth of would otherwise behaviour pattern was cities which have the buildings, geographical orienta- have been im- programmed developed along tion and the topography, are intro- possible to pre- into the virtual normal lines. A duced into the virtual environment calculate with townscape is known as the “village generator”. this clarity. The “house-builders” characterised by The virtual buildings are created by resulting forms axes, squares are organic in the and spatial den- architectural theoretical sense of the sity. Hence other laws had to be de- term, meaning that they have devel- fined for the simulation of urban oped from the inside to the outside. areas. Although simple, clearly de- Despite the fact that the pro- fined laws cover the necessary “ex- grammed modes of behaviour are posure” and “development” of the not directly derived from urban de- virtual houses, a complicated pro- velopmental experience, the results gramme of laws for behavioural pat- display close similarity to the exist- terns is required for controlling the ing structures found in mountain position and alignment of the neigh- villages. This forming of analogies bouring modules. This is effected for the development of complex discretely throughout the entire vir-

Above: Urban development modules can be crossed and „bred“ in a computer. Right: Generators sort the virtual buildings according to previously programmed laws, and at the same time they seek the most attractive sites for them.

generators which pass through the virtual world checking the attrac- tiveness of the location in line with prescribed environmental factors. A sort of communal “social” behav- iour is programmed amongst the virtual house-builders to enable them to change their direction de- pending on their proximity to their 82 neighbours. This so-called “swarm

german research SPECIAL 2004 calculated their effects. By means of programmed loops and recursive functions an approximation of an optimum result under the given conditions was created, whereby it was open to the designer to inter- vene at any time to control the course of computation. A pro- gramme is currently in course of de- velopment which will enable the

tual town, which means that each As in reality, the townscape is characterised individual house stands in formal in the simulator by axes, squares and spatial relationship to its neighbourhood. density, and is clearly distinguished from Each building informs its neigh- the structure of villages, which often create bourhood where subsequent build- a complex and random effect reminiscent of organic growth. Right: Each building ings can still be positioned. Struc- exerts control over any further building in tures or buildings can be imported its proximity by influencing the into the urban generator so that it is attractiveness of its surroundings (in blue). required to react to the current situ- ation. It is precisely during these ex- different urban planning modules to periments that astonishing similari- acquire their own form by learning. ties occur to actual urban planning price and residential density. For- Using “neuronal networks”, a form situations. mal characteristics were also ap- of programming based on the brain, Two of the most important and plied, such as size and mode of use. and “genetic algorithms”, the ele- complex tasks for architects and These data were then entered in the ments of the virtual world can be urban planners are that of building drawings in an order of priority re- trained to acquire intuitive behav- amidst standing structures and that flecting their weighting. The result- iour. These intelligent structural el- of addressing the problem of urban ing attractiveness was displayed as ements are to be furnished with se- concentration. For these it is essen- a three-dimensional structure in its lective perception of their surround- tial that the numerous parameters virtual surroundings. The result is ings, and their knowledge im- influencing the attractiveness of an abstract building. The designer proved in training units. each plot should be placed in their decided which conditions the new correct order of priority. Using a building had to meet, for example it Prof. Bernd Streich concrete example as a basis, a con- desired residential density or the Dipl.-Ing. Oliver Fritz trolled progressive increase in rough distribution of the individual Dipl.-Ing. Michael Lenhart urban density was created in a com- types of building in the area. He also Dr.-Ing. Ludger Hovestadt puter simulation. The drawings for a defined the limiting values for these Markus Braach block of buildings were generated different types of building (maxi- Kai Schübel on the computer and given certain mum height, optimum alignment or Karsten Droste characteristics in a virtual world. building depth). Universität Kaiserslautern These were quantitative parame- The computer now proposed Dr. Rivka Oxman ters, such as density of building, plot ways of increasing the density, and Technion Haifa 83

german research SPECIAL 2004 The Deutsche Forschungsgemeinschaft

The Deutsche Forschungsgemein- serve to transfer the findings of basic Other funding opportunities for quali- schaft (DFG, German Research Foun- research produced by Collaborative fied young researchers are offered by dation) is the central self-governing Research Centres into the realm of the Heisenberg Programme and the organisation responsible for promo- practical application by promoting Emmy Noether Programme. ting research in Germany. According cooperation between research institu- to its statutes, the DFG serves all bran- tes and users. Humanities Research Centres were ches of science and the humanities. created in the new federal states to The DFG supports and coordinates re- DFG Research Centres are an impor- improve the existing research infra- search projects in all scientific disci- tant strategic funding instrument. structure. These centres have been es- plines, in particular in the area of basic They concentrate scientific research tablished for a specific time period research through to applied research. competence in particularly innovative and serve to promote interdisciplinary Particular attention is paid to promo- fields and create temporary, interna- research. ting young researchers. Every Ger- tionally visible research priorities at research universities. The DFG also funds and initiates mea- man scientist and academic is eligible sures to promote scientific libraries, to apply for DFG funding. Proposals Research Training Groups are univer- equips computer centres with compu- are submitted to peer reviewers, who sity training programmes established ting hardware, provides instrumen- are elected by researchers in Germa- for a specific time period to support tation for research purposes and ny in their individual subject areas young researchers by actively invol- conducts peer reviews on proposals every four years. ving them in research work. This focu- submitted within the framework of ses on a coherent, topically defined, the Hochschulbauförderungsgesetz, a The DFG distinguishes between the research and study programme. Re- legal act which provides for major following programmes for research search Training Groups are designed equipment and the construction of in- funding: In the Individual Grants Pro- to promote the early independence of stitutions of higher education in Ger- gramme, any researcher can apply for doctoral students and intensify inter- many. On an international level, the financial assistance for an individual national exchange. They are open to DFG has assumed the role of Scientific research project. Priority Programmes international participants. In Interna- Representative to international orga- allow researchers from various re- tional Research Training Groups, a nisations, coordinates and funds the search institutions and laboratories to jointly structured doctoral programme German contribution towards large- cooperate within the framework of a is offered by German and foreign uni- scale international research pro- set topic or project for a defined period versities. grammes, and supports international of time, each working at his/her re- scientific relations. spective research institution. A Re- search Unit is a longer-term collabora- Illustrations Another important role of the DFG is tion between several researchers who to provide policy advice to parlia- generally work together on a research IPT-Aachen (cover, pp. 54/55, 55, 56 a. r.), ZEFA ments and public authorities on scien- topic at a single location. In Central – A. Inden (pp. 4/5, 5), Wissemann (p. 6), tific issues. A large number of expert Research Facilities there is a particu- Staats- und Universitätsbibliothek Göttingen commissions and committees provide (p. 7), Mauritius-Peebles (p. 8 a.), Lühr (pp. 8/9, lar concentration of personnel and the scientific background for the pass- equipment that is required to provide 10, 10/11, 11 b., 13), Zimmer (p. 11 r.), Subron- to (p. 12), Hüsken (pp. 14/15, back cover), Ner- ing of new legislation, primarily in the scientific and technical services. lich (pp. 14 b., 16, 17, 18, 19 a.), Leicester Gal- areas of environmental protection and health care. Collaborative Research Centres are lery, London (pp. 18/19), Popp (pp. 20 l., 23 b.), Mauritius-Age (pp. 20/21, 22/23), IWR Mül- long-term university research centres ler/Quien (pp. 24/25, 26, 27), ZEFA-Rauschen- The legal status of the DFG is that of a in which scientists and academics pur- bach (pp. 28/29), Universität Bielefeld (pp. 30, private association. Its member orga- sue ambitious joint interdisciplinary 31), Klimburg (pp. 32, 33, 34, 35, 36), Dover nisations include research universi- research undertakings. They are ge- Publications, N. Y., 1955 (p. 37), Pfeiffer/Cruse ties, the Academies of Sciences and nerally established for a period of 12 (pp. 38, 39), Kastenholz (pp. 40/41), Landes- Humanities, the Max Planck Society, years. In addition to the classic Colla- amt für Naturkunde Rheinland-Pfalz (pp. 41, the Fraunhofer Society, the Leibniz borative Research Centres, which are 42, 43), AMORE-Expedition (pp. 44/45, 46/47, Association, the Helmholtz Associa- concentrated at one location and open 47, 48, 49), Böhling (pp. 50, 51, 52, 53), ISF Aa- tion of National Research Centres, re- to all subject areas, the DFG also of- chen / Jäger (p. 56 a. l., b.), ISF Aachen / Möller search organisations of general im- (p. 57), Kramsky (pp. 58/59), Taccone (p. 60), fers several programme variations. Köhler (p. 61), Baehr (pp. 62, 63, 64, 65), portance, and a number of scientific Transregional Collaborative Research Deutsch, Langenhorst, Masaitis (pp. 66/67, 68, associations. In order to meet its re- Centres allow various locations to co- 69, 70, 71), Kruess (pp. 72/73, 74, 75), Tscharnt- sponsibilities, the DFG receives fun- operate on one topical focus. Cultural ke (p. 72), Haßler (pp. 76/77), Lenz (p. 78), ding from the German federal govern- Studies Research Centres are de- Archiv (p. 79), Universität Kaiserslautern/ ment and the federal states, as well as signed to support the transition in the Technion Haifa (pp. 80/81, 82, 83) an annual contribution from the Do- humanities to an integrated cultural Layout of pictures: l. = left, r. = right, nors’ Association for the Promotion of studies paradigm. Transfer Units a. = above, b. = below Sciences and Humanities in Germany. 84

german research SPECIAL 2004 round 25,000 research projects from all scientific disciplines are A currently funded each year by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation). More than 700 employees work at its head office in Bonn in the service of research funding.

Liaison offices in Washington, Moscow and Beijing serve to intensify international sci- entific cooperation. The DFG also has a branch office in Berlin, the main task of which is to maintain links to Parliament and the German Federal Government as well as to foreign embassies.

www.dfg.de