AÇOREANA, 2011, 7: 39-71

CHARLES DARWIN AND THE OF THE ATLANTIC OCEAN, THE MACARONESIAN ISLANDS, AND THE AÇORES

Brian Morton

Department of , The Museum, Cromwell Road, London SW7 5BD, U.K. e-mail: [email protected]

Darwin wrote in his notes for the Voyage of the Beagle when he stopped off at Terceira on 20 September 1836 on his way back to England: ‘I enjoyed my day’s ride, though I did not find much worth seeing’.

ABSTRACT The fi rst stop on 16 January 1832 on the voyage of H.M.S. Beagle was the island of Santiago in the Cape Verde Archipelago. While there, Darwin, only 22 years old and with a Cambridge degree in theology, examined an upli ed layer of fossiliferous sandy breccia sandwiched between lava fl ows. These fi rst observations eventually played an historic role in his and our understanding of ocean genesis and the colonization and subsequent evolution of island fl oras and faunas. The English botanist Joseph Hooker had noted fl oristic similarities between the Falkland Islands and Iceland, neither having hardly any indigenous , and South America and Europe, respectively. To explain this, the English malacologist Edward Forbes proposed in 1846 that a great land mass had existed in the Miocene encompassing northern Europe and Spain, and extending out from the Mediterranean far westwards into the Atlantic Ocean virtually to the coast of North America. On his return to England, Darwin became skeptical of Forbes’s lost land and sent of the Western Atlantic fabaceans gigas and Mucuna urens from Açorean beaches to the Royal Botanic Gardens at Kew where they were planted, germinated and produced healthy, mature, vines. Subsequently, Darwin set up his own experiments in the glasshouse at Down House where he immersed the seeds of 87 species of common in seawater for a month. He then tried to germinate them and found that over half (64) had survived. By his own calculations, ocean currents could thus have taken such seeds well over half way across the Atlantic Ocean. He undertook similar work on dried muds collected from the feet of migrating birds and concluded that no Forbesian landmass was necessary to explain Hooker’s biogeographic similarities.

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The observations of Darwin on Santiago eventually led on Cocos- Keeling in the Pacifi c to his concept of oceanic islands having either risen or sunk, or of levels falling and rising, respectively, or both. Darwin thus set in place an alternative, and more plausible, theory to that of Forbes, which suggested that newly-emergent islands could be colonized naturally by plants and animals from other locations and that, through natural selection, such isolated individuals could evolve into distinct species. Thus, although Darwin stayed but a few days in the Açores, the islands subsequently played a critical role in his understanding of the evolution of islands and life upon them. Terrestrially, the Açorean fl ora and fauna have been much modifi ed by the hand of man. This is also true of the few low-lying wetlands, but the islands remain, because of their Atlantic isolation, one of the best places to test Darwin’s hypotheses about island colonization and to eff ect Macaronesian marine conservation.

RESUMO A primeira paragem em 16 de Janeiro de 1832 na viagem do H.M.S Beagle foi a ilha de Santiago no Arquipélago de Cabo Verde. Enquanto ali, Darwin, com apenas 22 anos de idade e graduado em teologia por Cambridge, examinou uma camada erguida de breccia arenosa fossilífera entalada entre derrames de lava. Estas primeiras observações eventualmente tiveram um papel histórico no seu e nosso entendimento da génese do oceano e da colonização e subsequente evolução das fl oras e faunas das ilhas. O botânico Inglês Joseph Hooker notou semelhanças fl orísticas entre as Ilhas Falkland e a Islândia, nenhuma possuindo praticamente espécies indígenas, e a América do Sul e a Europa, respectivamente. Para explicar isso, o malacólogo Inglês Edward Forbes propôs em 1846 que uma grande massa de terra existiria no Mioceno abrangendo a Europa do Norte e a Espanha, e estendendo-se para fora do Mediterrâneo muito para oeste Oceano Atlântico adentro virtualmente até à América do Norte. No seu regresso à Inglaterra, Darwin tornou-se céptico quanto à terra perdida de Forbes e enviou sementes de fabáceas do Atlântico Oeste Entada gigas e Mucuna urens das praias Açorianas para os Royal Botanical Gardens em Kew onde foram plantadas, germinaram e produziram trepadeiras

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saudáveis, maturas. Subsequentemente, Darwin preparou as suas próprias experiências na estufa em Down House onde imergiu em água do mar durante um mês as sementes de 87 espécies de plantas comuns. Experimentou então germiná-las e descobriu que mais de metade (64) haviam sobrevivido. Por seus próprios cálculos, as correntes oceânicas poderiam pois ter trazido tais sementes bem mais do que metade do caminho através do Oceano Atlântico. Ele fez trabalho semelhante com lamas secas recolhidas das patas de aves migradoras e concluiu que não seria necessária a massa de terra Forbesiana para explicar as similaridades biogeográfi cas de Hooker. As observações de Darwin em Santiago levaram eventualmente, em Cocos-Keeling no Pacífi co, ao seu conceito de ilhas oceânicas haverem subido ou afundado, ou de mares descendo e subindo, respectivamente, ou a ambas as situações. Darwin então colocou uma teoria alternativa à de Forbes, e mais plausível, que sugeria que ilhas recém-emersas poderiam ser colonizadas naturalmente por plantas e animais de outras localidades e que, através da selecção natural, esses indivíduos isolados puderam evoluir em espécies distintas. Assim, embora Darwin tenha permanecido nos Açores apenas alguns dias, as ilhas subsequentemente desempenharam um papel crítico na sua compreensão da evolução das ilhas e da vida nelas existente. Em terra, a fl ora e a fauna Açorianas têm sido muito alteradas pela mão do homem. Tal é verdade acerca das poucas zonas húmidas baixas mas, devido ao seu isolamento no Atlântico, as ilhas permanecem um dos melhores lugares para testar as hipóteses de Darwin acerca da colonização das ilhas e para levar a cabo a conservação marinha da Macaronésia.

INTRODUCTION Darwin arrived at the University of to read medicine. harles Darwin was born on This lasted for but two years and C12 February 1809. One of the in 1828 (aged 19), Darwin enrolled greatest infl uences in his early at the University of Cambridge to life was his paternal grandfather read divinity. Unsuccessfully, as Erasmus Darwin (1731-1802) who it transpired. Here, however he recognized and described ‘biolo- came under the infl uence of two gical evolution’. In 1825 (aged 16), great men – the geologist Adam

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Sedgwick (1785-1873), who had not an outstanding student, in- become Woodwardian Professor deed his father ‘despaired of of at Cambridge in 1818, him’ but, today, there is a statue and the botanist John Stevens of as a young Henslow (1796-1861), who had man in the gardens of Christ’s been appointed Professor of College, Cambridge (Figure 1). at Cambridge contempo- On the steering wheel of H.M.S. raneously with Darwin in 1825. Beagle, however, were carved Darwin left Cambridge in 1931, the words of Nelson’s exhor- not a clergyman, but with a B.A. tation to his men at Trafalgar: in Theology, Euclid and Classics. ‘England expects every man to do He is now, however, with train- ing by Sedgwick and Henslow an enthusiastic, albeit, amateur geologist and botanist. On 24 August 1831, Henslow informed Darwin that there is a space for him on H.M.S. Beagle as natural- ist companion to Captain Robert FitzRoy (1805-1865). Darwin accepted the invitation and on 27 December 1831 (aged 22), he and the Beagle departed on her second voyage, principally to conduct a hydrographic survey of the coast of South America. The expedition was not to return to England until 2 October 1836, almost five years after it had set sail. In Cambridge, Darwin had become much influenced by the writings of (1797-1875), author of Principles FIGURE 1. The statue of Charles Darwin as a young man in the gardens of Christ’s of Geology and took Volume I College, Cambridge. ‘I believe that I was with him on the voyage and considered by all… [to be] an ordinary boy received Volume II on route.It well below the common standard of intellect’. has to be said that Darwin was Charles Darwin, 1876.

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his duty’. Such a daily reminder in 1462, they became impor- of his duty must have kept him tant as a stopping off point for working throughout the long the trans-Atlantic slave trade. periods of boredom, tedium, sea- Subsequently, the importance of sickness and homesickness that the islands declined. Darwin ar- he endured for the 58 months of rived at the capital, Porto Praya the voyage. (Praia), on the island of St Jago The Beagle’s last stop on its (Santiago) on the 16 January five year voyage was the Açores. 1832 (the Beagle’s first stop) Although Charles Darwin was and described his surroundings singularly unimpressed by the as wearing a ‘desolate aspect’ islands on his visits to Terceira (Darwin, 1845). and São Miguel in 1836, the At the time of Darwin’s vi- archipelago, along with other sit to Santiago, the Christian macaronesian ones would church still believed in the cos- eventually play an important mogony of James Ussher (1581- role in his understanding of 1656), Archbishop of Armagh, biogeography and the evolution Primate of All Ireland, and Vice- of island isolated floras and Chancellor of Trinity College, faunas. The first stop of the Dublin, who had identified crea- Beagle in 1832 was to be the tion as starting on Sunday 23 Canaries. The island’s Spanish October 4004 B.C. Such a view authorities, however, had heard had the important support of that cholera was rampant in Sir John Lightfoot (1602-1675), England and so forbade any Vice Chancellor of Cambridge landing. Instead, therefore, the University, who even added an first stop of H.M.S. Beagle was exact time - 9 a.m. - to the pre- the Portuguese colony of the scribed date. Having established Cape Verde Islands. the first day of creation, Ussher calculated the dates of other bi- THE CAPE VERDE ISLANDS blical events, concluding, for example, that Adam and Eve The Cape Verde Islands are were driven from Paradise on located 450 kilometres off the Monday 10 November 4004 B.C. coast of West Africa (Senegal) Charles Lyell, however, did and were discovered in 1456. not believe any of this. Rather, he Colonized by the Portuguese believed the Earth to be billions

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of years old. In addition to the When Darwin arrived on the debate regarding the Earth’s age, Cape Verde Islands – as deso- however, the scientific world late today through over-, was similarly divided as to as they were then, his mind was whether the geological record debating the conflicting views was (i), best interpreted as a in relation to creation, and the series of catastrophic events, the arguments about catastrophe most recent being equated with versus gradualism. Captain the deluge of Noah’s flood with FitzRoy, who was a devout crea- the ark touching down on Mount tionist, not just believing in the Ararat, according to Ussher, literal truth of Genesis but con- on Wednesday 5 May 2348 B.C. demning Lyell as a heretic too, (thereby achieving convergence between geology and scripture) or (ii), as Lyell believed, slowly acting processes of formation, erosion, deposition and defor- mation. The Temple of Serapis, at Pozzuoli, Naples, actually provided evidence of the latter, even then. Here, date mussels, Lithophaga lithophaga (dattero di mare) have made holes in the 2nd century columns, at a height of ~5.7 metres showing that they were originally uncovered, then covered and now, again, unco- vered by the sea – attesting, be- cause the columns were undis- turbed, slow, gradual, changes in sea level over historical time. The temple and its date mussel FIGURE 2. The Temple of Serapis, at artifacts were so important to Pozzuoli, Naples, where date mussels, Lithophaga lithophaga (da ero di mare) Charles Lyell that an illustration have made holes in the 2nd century of it (Figure 2) was used as a fron- columns, at a height (today) of ~5.7 tispiece to his book ‘Principles of metres. The frontispiece to Charles Lyell’s Geology’ (Lyell, 1830-1833). Principles of Geology (1830-1833).

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would be of little help to him in chamid (upper) shell valves, this debate. crab ‘fingers’ and maerl frag- But the harbour at Praia ments, attesting to its origin. on Santiago held a secret that That is, an uplifted shallow, tro- Darwin discovered. Here, on pical, seabed composed of large Quail Island (now Ilhéu de Santa sand grains, with a surface Maria) he noted the presence of cover of calcareous maerl nodu- a horizontal white band run- les (Darwin’s ‘coral’), attesting ning through the rocks, about 30 to gentle surface wavelets, and a feet (~10 metres) above sea-level mixture of organic fragments of, (Figure 3). It was composed of mostly, mollusc shells derived a sandy breccia, made of com- from rocky and sandy inshore pressed shells and ‘corals’ (actu- and soft offshore habitats. The ally maerl) and continued as far obviously suggest that as the eye could see. Figure 4A the whole area had once been shows some of the fossils collec- under water but, for Darwin, the ted by this author from Darwin’s question was: why not now? stratum on Quail Island in 2009. The geology of the Cape Verde The breccia matrix contains pa- Archipelago has been described tellid and fissurellid limpets, by Mitchell-Thomé (1972) and other gastropod fragments, ve- Figure 5 is the only detailed nerid, donacid, glycymerid and map of the geology of the

FIGURE 3. On Quail Island (now Ilhéu de Santa Maria) at Santiago in the Cape Verde Islands, Darwin noted the presence of a horizontal white band (arrow) running through the rocks about 30 feet (~10 metres) above sea-level. (Photo: B. Morton).

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FIGURE 4. A, Some of the fossils collected by this author from the limestone of Quail Island in 2009. The breccia matrix contains patellid and fi ssurellid limpets, other gastropod fragments, venerid, donacid, glycymerid and chamid (upper) shell valves, crab ‘fi ngers’ and maerl fragments. B, The coral Siderastrea radians a ached to a piece of Darwin’s fossiliferous limestone collected from the beach at San Tome on Santiago. (Photo’s: B. Morton).

twelve islands and shows that it dips locally below sea level they represent a within-plate in an asymmetrical fashion. In archipelago located some 500 Figure 6, A represents the sea; B, kilometres west of Senegal. The ancient volcanic rocks; C, upper archipelago probably dates back basaltic lava and arrowed is a some 180 Ma and the islands are thin layer of white limestone made up mostly of Tertiary and between them. younger volcanics. The oldest Four years later on into the rocks on Maio are Mesozoic voyage, H.M.S. Beagle stopped limestone but most are Cenozoic at the Cocos-Keeling islands (<65 Ma) and the most recent, as for but one day on 2 April 1836. on the northwestern-most tip of This stop was, however, also Santiago at Tarrafal are raised significant because his book ‘The beach deposits. For Darwin, the Structure and Distribution of Coral Quail Island limestone stratum Reefs’ (Darwin, 1842), illustrated was highly significant and he how various kinds of coral made a woodcut illustration of islands may be formed by either it (Figure 6: after Darwin, 1844, subsidence of the land or rises in p. 9) in which he showed how sea level (or both) and eventually

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in the Cape Verde’s. For here, he believed the maerl was ‘coral’ and, in fact, corals do occur in the shallow subtidal of the Cape Verde’s, for example Siderastrea radians here attached to a piece of limestone (Figure 4B), so that this must have been the first time he contemplated how such coral islands evolve. Also on Santiago, however, Darwin discovered an African baobab tree (Adansonia). His is no longer alive (Pearson & Nicholas, 2007), but there is FIGURE 5. The only geological map of the still a pair of trees to be found of the Cape Verde Islands showing that on the island in the valley the 12 islands represent a within-plate extending north from the archipelago located some 500 kilometres original capital, Cidade Velha, west of Senegal. (Courtesy of Dr Lyall Anderson, University of Cambridge). on the south coast of Santiago. The male tree illustrated (Figure 7, note the man standing beside lost to the depths still holds true it), and the female, are bigger today, attesting not only to his than Darwin’s and must have remarkable insight, but also to been mature when he visited the significance of Quail Island the island. Darwin also knew

FIGURE 6. The woodcut Darwin made of the limestone stratum on Quail Island, Cape Verde, in which he shows how it dips locally below sea level in an asymmetrical fashion. A represents the sea, B, ancient volcanic rocks; C upper basaltic lava with a thin layer of white limestone (arrowed), between them. (A er Darwin, 1844, p. 9.)

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importantly, because here his first thoughts on oceanic island formation were born and he began to question the accepted, literal, truth of creation.

FORBES’S LOST LAND

At the time of Darwin’s visit FIGURE 7. An African baobab tree to Cape Verde, the English natu- (Adansonia) today, on Santiago, Cape Verde Islands. (Note the man standing ralist, malacologist, geologist, beside it.) (Photo: B. Morton). palaeontologist and Professor of Natural Philosophy at Edinbugh University, Edward Forbes that the largest baobab trees (1815-1854), and therefore an could attain a great age of 6,000 eminent person, had proposed years. Could this therefore, be (Forbes, 1846) that a great land evidence for a lost landmass that had existed in the Miocene (7- had once connected Africa with 26 Ma) encompassing northern these Atlantic islands? If so, his Europe and Spain, and extending baobab must have sprouted in out from the Mediterranean, the first week of creation, but past the Açores (and thus way only if one believed in Bishop beyond the Canaries and Cape Ussher’s account of Biblical Verde), as far out into the chronology. But how, therefore, Atlantic as the Sargasso Sea. could this tree be older than the That is, virtually to the coast Quail Island fossils? The truth of North America (Figure 8). is, however, much more prosaic: Such a land largely filled the the trees were probably taken Atlantic Ocean. Hence, as far as to the Cape Verde Islands, as Forbes’s theory was concerned, seeds, by either slaves or their Darwin’s baobab would simply traders just a few hundred years be a remnant of a time when the previously. But, at the time, Cape Verde’s had been joined Darwin was not to know that. to Africa by this, now sunken, Nevertheless, Darwin’s sojourn inter-connecting landmass.The on Santiago was significant in English botanist Joseph Dalton a number of ways but, most Hooker (1817-1911), at 22 (the

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FIGURE 8. Forbes concept of a land that largely fi lled the Atlantic Ocean, thereby accounting for Hooker’s similarities in the plant and animal fossils of Europe and North America. (From Forbes, 1846).

same age as Darwin when he -known example at the time joined H.M.S. Beagle), enlisted was the beach (Lathyrus ja- on Captain James Clark Ross’s ponicus), illustrated in Figure Expedition to Antarctica (1839- 9, which was then thought to 1843). Subsequently, Hooker have a North American and rare noted the floristic similarities British occurrence and thus pro- between the Falkland Islands vide evidence of a formerly con- and Iceland, neither of which tiguous Atlantic distribution. had hardly anything indige- Edward Forbes’s lost landmass nous, and South America and also explained this, thereby fur- Europe, respectively. One well- ther accounting for similarities

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on H.M.S. Challenger that, on its famous, pioneering, voyage between 1872-1876, found life at 9,000 metres. Challenger, like the Beagle, put into Porto Praia on St Iago (Santiago), Cape Verde Islands, and Henry Nottidge Moseley (1844-1891), one of the naturalists on board, was keen to see the rocks described by FIGURE 9. The beach pea, Lathyrus Darwin - so significant had they japonicus. (B. Morton). become. Forbes died at an early age of in the plant and animal fossils of 39, his theories, though interes- Europe and North America. It is ting, all subsequently shown to now known that the beach pea, be wrong. But the Challenger whose seeds can survive many Expedition did more – its 50 months in seawater, has a cir- volumes of research findings, cum-polar distribution. Later, largely edited by John Murray Darwin, after looking at (1841-1914), who had been dispersal more scientifically, Wyville-Thompson’s assistant would offer an alternative hypo- on the voyage and who took thesis to that of Forbes. over the editing and publishing Forbes had also dredged of the expedition’s results (com- in the Aegean from 1841-42 pleted in 1896), effectively, laid aboard H.M.S. Beacon giving the foundations for the mo- rise to his second, Azoic (or dern science of . Lifeless), theory, that no life Murray, for example, was the existed below a depth of ~500 first person to note the existen- metres. This view, too, would ce of the Mid-Atlantic Ridge and later be challenged by Charles ocean trenches and, indeed, coi- Wyville Thompson (1830- ned the word ‘oceanography’. 1882) who succeeded Forbes as And, for continuing and refining Professor of Natural Philosophy this newest of sciences, we have at Edinburgh University. to thank the researches of three Thompson aimed to disprove other 20th century physical ocea- the Azoic Theory and did so nographers.

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ALFRED WEGENER, EDWARD BULLARD AND FREDERICK VINE

Forbes’ view of a sunken land bridge across the Atlantic persisted into the 20th century and it was not until 1911 that the German meteorologist Alfred Wegener (1880-1930), noticing that the fossils of identical plants and animals could be found on opposite sides of the Atlantic, suggested that the continents were ‘drifting’ apart. Orthodox science, that is, those believing Forbes, at the time explained this by postulating that land bridges, now sunk, had once connected far-flung conti- FIGURE 10. The maps in the 1966 nents. Wegener also, however, edition of A. Wegener’s book illustrating continental dri for three epochs. noted the close fit between the coastlines of South America and Africa and wondered whether the continents might not have (1907-1980), who became profes- been joined at one time. He ar- sor of Geodesy and Geophysics gued the continents could drift at Cambridge University, later about, laying down the ground- produced a computer fit of the work for the 1950’s palaeomag- continents that Wegener had netism research that reconstruc- called ‘Pangaea’, showing just ted the world’s historical geolo- how the continents do actually gy in terms of a unified theory fit very closely into a jigsaw-like of continental drift. Figure 10 picture. shows the maps in the 1966 edi- In 1963, the Cambridge geo- tion of Wegener’s book illustra- physicist Frederick Vine (born ting continental drift for three 1939) proved the concept of sea- epochs. Edward Crisp Bullard -floor spreading by studying

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the reversals in the polarity of they were planted, germinated the Earth’s magnetic field. Vine and produced healthy mature showed that the parallel bands vines. Clearly, these and, indeed of palaeomagnetic anomalies other seeds of several species of on either side of oceanic moun- sea beans are capable of survi- tain ridges resulted from the ving Gulf Stream transport from combined effects of reversals in the tropical Western Atlantic to the polarity of Earth’s magnetic the Açores, including Mucuna fields and the generation of new urens as well as M. sloanei and floor along the axes of the rid- M. fawcetti. The seeds of these ges. Today, through the science three species of coastal legumi- of geomagnetism, we can inter- nous vines share the characteris- pret the evolution of the earth’s tic of a darkly pigmented hilum continents and oceans over time, encircling five-sixths of the mar- explaining why similar fossils gin of each. The embryo within occur on different continents. the seed is protected by a thick, Through the pioneering work of resistant, exocarp capable of Wegener, Bullard and Vine, we prolonged exposure to seawater now know an enormous amount (Gunn et al., 1976). about the Earth’s seabed, inclu- In fact, the Açores receives a ding its age(s) and about the pla- variety of seeds and vegetative tes that form the continents and dissemules, many of which ori- are separated from each other ginate from the tropical Western by the mid-oceanic ridges. The Atlantic (Table 1). The sea heart, Açores Archipelago sits on the Entada gigas, is the most com- Mid-Atlantic Ridge. mon disseminule on Açorean be- aches, delivered by Gulf Stream DARWIN’S EXPERIMENTS currents from Caribbean shores. Entada gigas is a large, climbing, Upon his return to England, tropical, coastal, vine producing Darwin became skeptical of large chocolate-brown seeds up Forbes’s lost land and after re- to six centimetres in diameter ceiving several seeds of the and some two centimetres thick. Western Atlantic Entada gigas The seeds are buoyant and can and Mucuna urens from Açorean remain afloat at sea for at least beaches, sent them to the Royal two years (Gunn et al., 1976). Botanic Gardens at Kew where Veríssimo (1989) suggested that

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TABLE 1. Plant disseminules recorded from Açorean beaches (a er Gunn et al., 1976). Disseminule Common name Family Source, habit and habitat Astrocaryum sp. Starnut palm Palmaceae Caribbean; wet lowland forest tree

Calocarpum mammosum Egg fruit Sapotaceae Tropical America; tree

Crescentia cujete Calabash tree Bignoniaceae New World tropics; tree

Dioclea refl exa Sea purse Leguminoseae Asia; vine

Entada gigas Sea heart Leguminoseae Caribbean; climbing vine

Manicaria saccifera Sea coconut Palmaceae American tropics; coastal tree

Merremia discoidosperma Many’s bean Convolvulaceae Central America; woody, wet forest

Mucuna sloanei True sea bean Leguminoseae Caribbean vine

Sacoglo is amazonica Cojon de burro Humiriaceae South America; lowland forest tree

Sapindus sapinaria Black pearl/Soapberry Sapindaceae American tropics; tree

Christopher Columbus (1451- germinated after an immersion 1506), upon finding E. gigas period of 28 days and a few seeds along the shores of either survived immersions of 137 Porto Santo or Madeira during days. Nine legumes were tried his residence on the islands be- and, with one exception, all tween ~1479-1482, used the ob- died, including the common servation to support his argu- pea (Pisum sativum) although, as ment for, an as yet undiscove- noted above, it is known that the red (then in ignorance of Viking sea pea occurs in North America achievements and the evidence and along the southeast coast thereof on Newfoundland), west- of England, for example on the ward land – the Americas – or, Dungeness shingle banks, on the rather, as he thought, Asia. southeast coast of England, and As a consequence of the has a circum-polar distribution. results of the Kew experiments, Darwin also noted that Darwin set up his own in the many of the seeds, without Old Laboratory and Greenhouse either the capsule or fruit, sank in the grounds of Down House within a few days and could where he immersed the seeds of not, therefore, have survived a 87 species of common plants in long sea voyage. Later, he tried seawater for a month. He then larger fruits and capsules and tried to germinate them and, to eventually to dry and then try the his surprise, 64 subsequently stems and branches of 94 plants

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with ripe fruits. The majority to evolve into distinct species. sank quickly, including fresh Thus, Darwin’s interpretation cuttings whereas dried ones of the stratum on Quail Island floated for longer. For example, initially stimulated him to think ripe hazelnuts sank immediately about how oceanic islands are whereas dried ones floated formed, but his experiments on for 90 days and subsequently seed dispersal also demonstrated germinated, as did the ripe to him how such new entities seeds of Helosciadium (water might be colonized. This latter parsnip) and an asparagus-plant observation ultimately led to his (Asparagus officinalis) with ripe great theory about the evolution berries (85 days). Of the 94 dried of life itself. plants, 18 floated for >18 days. Darwin consulted ‘Johnston’s THE AÇORES Physical Atlas’ wherein it was stated that the average rate of The Açores archipelago is several Atlantic currents is 33 located on the Mid-Atlantic miles·day-1, with some running Ridge on its only triple junction. at 60 miles·day-1, and concluded The discovery of the Açores, that 14 out of 100 (14%) plants according to 14th century might be floated across 924 miles Genoese maps, the Portulanos, of sea and if blown to a favourable seems to have taken place spot, would germinate. By his between 1317 and 1339 (Bento, own calculations, therefore, 1994) but the Portuguese ocean currents could thus have navigator Diogo de Silves is taken such seeds well over half credited with the discovery of way across the Atlantic, that is, the islands in 1427. Portuguese easily, to the Açores. settlers first colonized the islands Darwin’s experiments thus permanently beginning with set in place an alternative, more Santa Maria in 1432, São Miguel plausible, theory to that of in 1439 and the other seven Forbes and which suggested that subsequently. Darwin and the newly emergent islands could be Beagle stopped off in the Açores colonized by plants and animals (the last stop) for six days on the from other locations and that way back to England and visited through natural selection such Terceira on 20 September 1836 isolated individuals could come and São Miguel subsequently,

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although he probably did not the nine Açorean islands to have disembark the ship at the latter. a sedimentary cover and has a His comment about Terceira rich record dating from (Darwin, 1845) was: the Late Miocene-Early Pliocene to the Pleistocene (Madeira et ‘I enjoyed my day’sride, though I al., 2007). As on Santiago in the did not find much worth seeing’. Cape Verde Islands, there is on Santa Maria an uplifted Early We have to remember, Pliocene fossiliferous stratum however, that Darwin was and Janssen et al. (2008, figure terribly homesick, indeed had 3) illustrate an accumulation been for many months. He of Cavolinia marginata in a even dismissed Australia as crustacean burrow from the uninteresting! There, he did not Lower Pliocene of Cré, on this even see a kangaroo! As we now island. Ages of fossil molluscs know, however, the Açorean recovered from Santa Maria islands are extremely interesting, range from 10.03 to 2.24 Ma especially geologically. Santa (Kirby et al., 2007). Maria is the oldest island of the Similarly, to the rear of the Açores and arose from the sea long expanse of sandy beach in the Late Miocene ~7 million on the southern shore of Porto years ago. It is the only one of Santo, one of the Madeiran islands, there is a raised beach of offshore sand (Figure 11) not unlike that seen on the coast at Tarrafal on Santiago (Cape Verde Islands). Hence, throughout Macaronesia, there is ample evidence of uplifted marine sediments attesting not only to active vulcanism over relatively recent time but to the insight of Darwin in recognizing this very FIGURE 11. A raised beach towards the early on during his voyage with rear of the long sandy beach on the south the Beagle. coast of Porto Santo, Madeira. (Photo: B. We also know that sometime Morton). between 3.1-3.6 million years

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FIGURE 12. The map of the Gulf Stream created by Benjamin Franklin on 2 May 1775. He thought of it as a river.

ago, after the Middle Pliocene by Benjamin Franklin (1706- upli of the Central American 1790), who was postmaster Seaway, the connection between general of the American colony the Pacifi c and Atlantic Oceans at the time, during a voyage from was closed at the approximate England to the soon to become position of modern Panama United States in 1775 (Figure 12). (Vermeij & Rosenberg, 1993), iso- He recorded that the current was lating coral reefs in the Caribbean some 3.5 °C warmer than the and creating the modern pa ern surrounding sea and by taking of circulation of both oceans, but regular temperature readings importantly for the Atlantic – the could trace its course. It is this Gulf Stream –, first mapped current which allows the Azores

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to be colonized sporadically by colonization times and routes species with long-lived larvae but also marine biogeography. from the Caribbean, such as Today, the Açorean islands the taenioglossan tonnoidean are influenced by the North gastropod Charonia variegata Atlantic Current at the surface (Lamarck, 1816) recorded only and by water arriving from once from Faial at 15 metres the Mediterranean at mid- depth (Gofas & Beu (2002). Also water depths. The variety of in the early Pliocene, the Bering currents influencing the islands Strait between Alaska and Siberia at different depths thus has the opened and cool-temperate and potential therefore to create polar marine species were able in the Açores a meeting place to move between the North of marine plants and animals Pacific and the Arctic-Atlantic from diff erent locations (Morton basins (Vermeij, 1991). et al., 1997). It should therefore Such relatively recent histori- be possible to monitor past cal events have been responsible and present colonization (and for not just the Atlantic circula- spreading) events to not just test tion pattern we see today, but Darwin’s theory of island and also for the species of marine biological evolution but to expand plants and animals found on it into a programme that tests the shores and shallow subtidal current ideas about the human- waters of the Macaronesian, in- assisted introduction of exotic cluding Açorean, islands as they species (Morton & Bri on, 2000b). arose successively either prior or subsequent to these major events The above-described variety (Morton & Britton, 2000a). We, of ocean currents is predomi- therefore, know much about the nantly responsible for the histo- circulation of the Atlantic Ocean rical import onto the Açorean is- and how it has evolved and in lands’ shores of its characteristic broad terms how and when the marine flora and fauna (Morton marine biota of the Açorean is- & Britton, 2000a). Just as Darwin lands arrived. That the islands showed with plant seeds, emerged either before or after Dinesen (pers. comm.) has sug- these events, however, make gested that the planktonic lar- them a chronometer for the tes- vae of many marine invertebra- ting of theories related to island tes may spend up to four weeks

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in the upper water mass where been colonized since the early current speeds of ~1.8 km h-1 are part of the 15th century, the ori- common. Such larvae, again as gins and routes of such intro- with Darwin’s seeds, could thus ductions have been lost in time. be transported ~1,200 kilome- Morton & Britton (2000b) have tres from their spawning site and reviewed this subject. hence easily reach Açorean waters. Subsequently, such larvae may AÇOREAN BIOTIC travel for up to three weeks in ENDEMICITY near-bottom waters before set- tling is required for post-meta- The terrestrial environment morphic survival. During this of the Açores has been much time, at a common speed for near modified by man since the initial bottom advection of 0.18 kilome- colonization of the islands in the tres hour-1 (50 mm second-1), early part of the 15th century. the larvae could be transported Thus, of the ~3,000 species of horizontally for a further 90 ki- vascular plants found on the lometres, during which time Açores, only 72 [68 according settlement-inducing cues could to Borges & Gabriel, 2009] are be encountered. Hence, it is endemic (the Açorean enigma; not surprising and despite their Carine & Schaefer, 2009) and, isolation, that the marine envi- even so, some 52 of these ronment of the Açorean islands are considered threatened. comprises communities, which Borges & Gabriel (2009) have contain species that are largely catalogued the terrestrial taxa encountered elsewhere, notably of the Açores and identified in the Mediterranean (Morton a total of 4,515 species. Of & Britton, 2000a) and that are these, 420 are considered to be transported to them in surface endemic: that is, 267 , ocean currents. 68 spermatophytes, 12 lichens, Thus, both algae and animals 9 bryophytes, 49 gastropods, 3 may have arrived at the Açores nematodes and 13 chordates. with ocean currents, or through Some endemic terrestrial bio- rafting on mats of floating vege- diversity may have been lost tation or wood and via human because it is estimated that, interventions although, in the overall, but 2% of natural forest latter case, as the islands have remains on the islands.

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This has had readily identi- the degree of isolation, that is, fiable consequences for some the distance from a mainland species and in the past, the sta- and its biota. In the case of the tus of the endemic Açorean bull- Açores, some 1,200 kilometres finch – the priolo – (Pyrrhula mu- from mainland Europe, combi- rina) was considered threatened ned with the relative youth of although it is possibly making the islands, the low level of en- a recovery in some locations. demicity is hardly surprising. Interestingly, this species is to- Further, even though they are day restricted to the eastern end, volcanic, oceanic islands are ty- Nordeste, of the island of São pically unproductive. This is be- Miguel. In Darwin’s time, howe- cause such young, steep, islands ver, it would have had a much cannot hold water nor retain nu- wider distribution on this island trients and this helps us under- and thus if he had landed on São stand why the carrying capacity Miguel, he may well have seen it, of islands is low. That is, they easily recognized it as subtly cannot sustain the energy-ex- different from the European pensive lives of large animals, bullfi nch (Pyrrhula pyrrhula) and, either herbivorous or carnivo- thereby, not only considered the rous. Similarly, there are few en- Açores to be more interesting demic species of marine plants than he did, but obtaining a clear and animals on such young is- example of island endemicity. We lands (Morton & Britton, 2000a, have to remember, moreover, that b). Some algae, a couple of Darwin did not discover the signi- fi shes, a chiton, an ophiuroid, fi cance of the Galapagos fi nches’ a few sponges, barnacles and, endemicity until a er his return possibly, some of the 20 rissoid to England – the priolo, however, gastropods recorded from the had he seen it, might well have Açores, including Alvania medio- revealed it to him whilst on the littoralis (Ávila et al., 2008), are voyage. considered to be endemic. As Of the 107 species of Açorean more research is undertaken, terrestrial , some 50% (49) however, so either conspecifics are endemic (Borges & Gabriel, or very closely related species 2009). Island endemicity is re- are found nearby, such as in the lated to age, size, elevation, Mediterranean, the Canaries or, climate, niche availability and even, on seamounts elsewhere.

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Frias Martins (1995) recognized northern shore of the island of the Açorean rocky shore elobiid São Jorge. The sea grass Ruppia Ovatella vulcani as endemic, maritima is known only from Fajã but as this is a pulmonate, like dos Cubres (Morton et al., 1995) its endemic terrestrial leptaxine whilst within the sediments of relatives, this may well be true. Fajã de Santo Cristo, also on São The intertidal limpet Patella can- Jorge, occurs the only known, dei gomesii is considered to be probably introduced, popula- an Açorean endemic subspecies tion of Venerupis decussata in the (Cúrdia et al., 2005). Macaronesian islands (Morton & With such a wide variety of Tristão da Cunha, 1993). Both of degrees of exposure to wave ac- these lagoons have been descri- tion in the Açorean littoral, there bed in general terms by Morton is a propensity for great mor- & Tristão da Cunha (1993) and phological variation as has been Morton et al. (1995, 1998), and demonstrated for the only com- there is a marsh at Lajes on the mon intertidal littorine, Littorina island of Pico and which has striata (Backeljau et al., 1995). been described, also in general Without care, such ecopheno- terms, by Morton et al. (1996). typic variation may lead to the All these isolated miniature la- unwarranted description of en- goonal wetlands are threatened demicity. and are in urgent need of greater study. For example, it MARINE CONSERVATION IN has been shown by Jordaens et THE AÇORES al. (2000) that there has been a loss of genetic variation in the The only places where ter- strongly isolated population of restrially derived nutrients are Tapes (=Venerupis) decussata in retained on steep, typically re- the Fajã de Santo Cristo such that cently formed, volcanic, off- it is highly vulnerable to extirpa- shore islands are lagoons and tion. this makes such habitats extre- In some locations on the mely important. By their very Açores we can demonstrate that nature, the young Açorean is- marine colonization has been not lands arise near vertically from just fast, but dramatic, occurring the seabed and two lagoons oc- within just a few years. On the cur on the steep (precipitous) island of Terceira, there was a

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FIGURE 13. A, The quarry at Cabo da Praia on Terceira in 1995 and B, in 2006. (Photo’s courtesy of J.A. Paulus Bruno).

marsh at Paul, Praia da Vitória now, 26 species identified. It is (Morton et al., 1997). This, today considered to be the most however, has now been drained. significant coastal wader site in There was, however, a coastal the archipelago. The question is, quarry at Cabo da Praia, also however, since, the quarry was on Terceira, and which when only constructed in ~1983, how studied for the book ‘Coastal did such a collection of species of the Açores’ (Morton et come to colonize it? al., 1998) was found to contain tidally inundated pools (Figure 13A). It was also shown to be home to numerous species of coastal plants, two species of Assiminea (Gastropoda), the amphipod Orchestia mediterranea and, a near-unique (for the Açores) collection of migrating coastal birds including some American vagrants, for instance, FIGURE 14. The fl oor of the quarry at Cabo the Hudsonian godwit (Limosa da Praia on Terceira in March 2010 a er a haemastica). Since first described cleanup by the Environmental Division of by Morton et al. (1997), growing Bensaúde, one of the companies that has numbers of bird species have a concession for the fuel storage facilities at Pedreira do Cabo da Praia, adjacent been recorded from the quarry to the wetland. (Photo: Marco Lopes, at Cabo da Praia (Table 2) with, Bensaúde).

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TABLE 2. Birds recorded from the quarry at Cabo da Praia, Terceira. July 1997 October 1997 July/August February 2006 March 2006 Species (Morton et al., (Morton et al., 2007 (S. Rodebrand) (B. Carlsson) 1998) 1998) (B. Carlsson) Charadrius hiaticula (Ringed plover) 3 1 Charadrius dubius (Li le-ringed plover) Pairs 20-30 (96-126, x = Charadrius alexandrinus (Kentish plover) 30 (Resident) 30 39 30 >112 in May and June) Charadrius semipalmatus (Semipalmated 1- plover) 1 (First 6 (Winter Pluvialis squatarola (Grey plover) summer) plumage) Calidris canutus (Red knot) 7 3 3 Calidris alba (Sanderling) 1 >100 41 60 Calidris minuta (Li le stint) 3 3 Calidris minutilla (Least sandpiper) 1 - Calidris fuscicollis (White-rumped 1- sandpiper) Calidris ferruginea (Curlew sandpiper) 2 2 5 (Winter Calidris alpina (Dunlin) 4 plumage) Tringa ochropus (Green sandpiper) 1 3 (breeding Limosa limosa (Black-tailed godwit) 11 plumage) Limosa lapponica (Bar-tailed godwit) 8 1 Limosa haemastica (Hudsonian godwit) 1 Numenius phaeopus (Whimbrel) 2 1 6 4 12 (Adults + Arenaria interpres (Turnstone) 20 29 50 (29-68, x = 54) fi rst summer) Philomachus pugnax (Ruff )1 Sterna hirundo (Common tern) Present 40 Sterna dougallii (Roseate tern Present 2 Larus cachinnans (Yellow-legged gull) Present 3 (Winter Larus ridibundus (Black-headed gull) plumage) Ardea cinerea (Grey heron) 3 4 Egre a garze a (Li le egret) 1 2 Anas platyrhynchos (Mallard) 2 females

Charles Darwin also pondered earth adhering to it. … the earth such a question and in the The had been kept for three years, but Origins of Species by means of when broken, watered and placed Natural Selection, he considered under a bell glass, no less than that birds might be responsible 82 plants sprung from it…’ and for such rapid colonizations. He ‘can we doubt that the many birds reported that: which are annually blown by gales ‘..the leg of a red-legged partridge across great spaces of ocean and (Caccabis rufa) had a ball of hard which annually migrate….must

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occasionally transport a few seeds upon whose shoulders Darwin embedded in dirt adhering to their stood. John Stevens Henslow feet or beaks’ (Darwin, 1878). was Darwin’s early botanical Regrettably, along with the mentor. The botanist Joseph destruction of the marsh at Dalton Hooker inspired Darwin Paul, the entrance to the unique, to study biogeography and how man-created, quarry habitat at plants are transported across Cabo da Praia, has been largely the oceans. Darwin’s greatest developed (Figure 13B). But mentor, the geologist Charles what a wonderful project it Lyell, inspired him to think first would have constituted to test about geology (on Cape Verde) Darwin’s theories of how coastal and then to marry his thoughts plants and maybe animals could on this subject with his others have colonized Açorean shores on biology to come up with the – both by transport across the great unifying theory of the evo- sea with ocean currents and by lution of life on Earth, but also birds. the evolution of the Earth itself. A postscript to this develop- And, eventually, to discover how ment, however, is that one of the island floras and faunas are ob- companies which has a conces- tained and, themselves, evolve sion for the fuel storage facilities in wonderful isolation. Robert at Pedreira do Cabo da Praia on FitzRoy, Captain of H.M.S. Terceira, adjacent to the quarry, has, in March 2010, undertaken a cleanup of the floor of Cabo da Praia (Figure 14), perhaps signaling a change in environ- mental awareness in relation to this highly important Açorean wetland.

Many great men both taught and influenced Charles Darwin, as a young, 22 year-old, adven- FIGURE 15. The eruption of Sabrina turer on H.M.S. Beagle. These Island on 19 June 1811, as drawn by included a number of distin- Lieutenant John William Miles of H.M.S. guished 19th century scholars Sabrina. (A er Tillard, 1812).

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Beagle, became the foil against third son so that, in many ways, whom, as his companion natu- the cultural and, especially, the ralist, Darwin debated the ideas maritime histories of Portugal that were slowly fomenting in and England are inextricably his mind. FitzRoy eventually linked, even today. I had the became a Vice-Admiral, famous privilege of meeting Colonel in his own right for creating the Agostinho in 1965 in Angra do modern science of weather fore- Heroísmo. casting. As a devoted Christian, Although the Açorean islands however, he would eventually were of little interest to Darwin divorce himself from Darwin’s when he visited them in 1836, heresy and, as he saw it, unjus- his views changed subsequently. tly awarded fame, and commit- Firstly, his attention was drawn ted suicide by cutting his own to the islet of Sabrina that arose throat on 30 April 1865. from the sea during June and Interestingly, an eminent July 1811 (Tillard, 1812) just Açorean, Colonel José Agostinho opposite Ponta da Ferraria (1888-1978), became chief on São Miguel (Figure 15). scientist with the Portuguese Coincidentally, H.M.S. Sabrina National Weather Service and, was in the vicinity and onto the for providing the British with shores of the newly formed islet meteorological and sea-state stepped Captain James Tillard to data during the Second World claim it for Great Britain. This War, was made an Honorary caused a diplomatic rift until the Commander in the Order of the islet disappeared back into the British Empire by King George sea from which it had arisen in VI. This act and its recognition August 1811. Nevertheless, for is in remarkable recognition of Darwin, this was incontrovertible the Anglo-Portuguese Alliance proof that volcanic islands of 1373. This came about when do arise and may sink over John I (1358-1433), the tenth King the course of their lifetimes, of Portugal and the Algarve, albeit with great differences in now famously, married, in 1387, rates. A similar event occurred Philippa of Lancaster, daughter in the 20th century when the of John of Gaunt (1340-1399) Capelinhos volcano erupted of England. Prince Henry the on the west coast of Faial in Navigator (1394-1460) was their 1957. This eruption was studied

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by the Açorean vulcanologist However, more interestingly, Frederico de Menezes Avelino in response to a request from Machado (1918-2000) and which Furtado for research advice, in when I visited it in 1965 was still a reply letter dated 3 July 1881, volcanically active. Machado Darwin suggested to him that: was assisted in this research by (1), If possible, the most distant Victor Hugo Lecoq de Lacerda outlying islands and their plants Forjaz (born 1940), who became and animals should be com- Professor of Vulcanology at pared with those of the other is- the University of the Açores lands; (2), all the plants and ani- and is today Director of the mals from the highest mountain Observatório Vulcanológico e summits on all the islands ought to Geotérmico dos Açores. be collected; (3), searches made Secondly, and more impor- for glacial deposits and for the tantly, however, Darwin en- presence of fossil remains, in tered into correspondence with such stones and (4), any light- Francisco d’Arruda Furtado -houses should be inspected for (1854-1887), a native Açorean, any land-birds that might have much interested in natural his- flown into the glass and killed. tory, a devotee of Darwin, and In such cases, their feet and beaks a believer in evolution through should be examined not only for natural selection. Darwin was earth, but the whole contents of perplexed as to how the lizard their alimentary canals dried out (Lacerta dugesi), earthworms and and placed on damp pure sand snails had arrived in the Açores. under a small bell-glass to see He asked Furtado specifically if any seeds are present which to determine if the lizard’s eggs would germinate. If so, grow could survive in seawater. The any plants and name them. truth is probably much more Thirdly, as described above, prosaic, however: all could have Darwin knew that seeds from the arrived, except for the endemic New World occurred regularly leptaxine snails (van Riel et al., on Açorean beaches and he used 2005) via human interventions. this fact as the raison d’etre for his Indeed, Chaves (1949), provides experiments on the survival of an introduction date of 1860 for seeds and other plant pieces in the Macaronesian lizard although seawater. Thus, when asking his this seems highly improbable. friend Joseph Hooker for seeds

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to be collected from Hitcham in ding of the forces that created Suffolk, England, he specifically the archipelago and how they requested that they include became colonized show us what those from plants also known to is important with regard to mari- grow in the Açores. ne conservation in the Açores. Hence, although Darwin’s vi- The predominant rocky shores, sit to the Açores was not initially washed by oceanic currents are inspiring, the islands subsequen- probably going to provide us tly became so for him. Similarly, with only a few, if any, examples he laid down the initial basis for of endemic species. There may our understanding of how the similarly be few endemic spe- Açorean flora and fauna was cies making up the communities obtained. Finally, however, and of other intertidal habitats. In although the word conservation one or two places in the Açores, was not in Darwin’s vocabulary however, there are intertidal, (in the natural history sense), his lagoonal, wetlands. In particu- researches upon and understan- lar, Fajã dos Cubres and Fajã de

FIGURE 16. An illustration showing the origins of mankind from Paradise – Lemuria – located in the Western Indian Ocean. The frontispiece to Ernst Haeckel’s History of Creation (1876).

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Santo Cristo, both on São Jorge, nued to argue that human evo- the marsh at Lajes on the island lution consisted of exactly 22 of Pico and, especially, the quar- phases, the 21st (back in time), ry at Cabo da Praia on Terceira, being the ‘missing link’ and re- have much to reveal about how presenting a halfway step betwe- such isolated communities have en apes and humans. But, that become established – a question our origins were still in Paradise that Darwin was deeply concer- (Figure 16). Clearly, even this ned with, but who never saw enlightened contemporary of these little habitats in the Açores. Darwin, still felt the need to ack- In particular, the modern quarry nowledge the Christian orthodox at Cabo da Praia, on Terceira, view of Genesis. But the illustra- because it is isolated from sea, tion represents more, because its except via the surrounding ba- image of human evolution still saltic rock wall filter could tell resonates today in the minds of us much about the origins of the some, generations later, and high- Açorean biota and, more interes- lights the continuing struggle tingly, how its representatives between science and faith for the have obtained purchase on the soul of humanity and haunts the islands. progress of humankind towards In his understanding of the a more tolerant world. evolution of life, Darwin also In the context of island discovered important facts con- evolution, however, and espe- cerned with the evolution of cially in the comparatively new the Earth, thereby achieving the geological context of the Açores, marrying of biology and geo- the researches of Charles Darwin logy, that is, the unifi cation of remain unchallenged and are the history of life on Earth and, critical to our understanding fi nally, the rejection of the bi- of island biogeography. And it blical account of creation. It is his seminal discoveries that is interesting though, that have, in turn, led to a better despite meeting, believing in understanding of the need for evolution through natural se- conservation not only on land, lection and supporting Darwin, but also on the riparian edge Ernst Haeckel (1834-1919), the of the sea, especially on island great German anatomist, em- archipelagos where new found bryologist and illustrator, conti- life clings precariously.

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ACKNOWLEDGEMENTS ta from the Azores (, Prosobranchia). Açoreana, Supple- I am grateful to my friend ment [4]: 159-171. Professor A.M. de Frias Martins BENTO, C.M., 1994. History of the for inviting me to participate in Azores, 165 pp. Translated from the conference ‘Darwin’s mistake the Portuguese by Pilar Vaz do and what we are doing to correct it’ Rego Pereira. Ponta Delgada, São in 2009 and for critically reading Miguel, Açores. the first draft of the manuscript BORGES, P., & R. GABRIEL, 2009. of this paper. I am also indebted Predicting extinctions on oceanic is- to Dr. E.M Harper and Dr. lands: arthropods and bryophytes / Lyall Anderson, Department Estimar extinções em ilhas oceânicas: of Earth Sciences, University artrópodes e briófi tos, 80 pp. Grupo of Cambridge, for providing de Biodiversidade dos Açores, Figures 1 and 5, respectively, Angra do Heroísmo. and for much practical help in CARINE, M.A., & H. SCHAEFER, my search for information about 2009. The Azores diversity enig- the Cape Verde Islands and ma: why there are so few Azorean Charles Darwin. endemic fl owering plants and why are they so widespread? Journal of LITERATURE CITED Biogeography, 2009: 1-13. CHAVES, F.A., 1949. Introdução de ÁVILA, S.P., P.J. MELO, A. LIMA, algumas espécies zoológicas na A. AMARAL, A.M. de FRIAS ilha de S. Miguel depois da sua MARTINS & A. RODRIGUES, descoberta. Açoreana, 4: 325-342. 2008. The reproductive cycle CÚRDIA, J., A.S. RODRIGUES, of the rissoid Alvania mediolit- A.M.F. MARTINS & M.J. COSTA, toralis Gofas, 1989 (Mollusca, 2005. The reproductive cycle of Gastropoda) at São Miguel Island Patella candei gomesii Drouët, 1858 (Azores, Portugal). (Mollusca: Patellogastropoda), Reproduction and Development, 52: an Azorean endemic subspe- 31-40. cies. Invertebrate Reproduction and BACKELJAU, T., K. BREUGELMENS, Development, 48: 137-145. C. BRITO, L. de BRUYN, H. de DARWIN, C., 1842. The Structure and WOLF & J.-M. TIMMERMANS, Distribution of Coral Reefs. Being the 1995. Macrogeographic genetic First part of the Voyage of the Beagle homogeneity in Li orina stria- under the Command of Capt. FitzRoy,

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