[Back to internetlibrary.html] Wolf-Ekkehard Lönnig 8 May 2007 (last update 16 October 2010), updates 27 Oct. 2007 with Appendix on Cameron & du Toit 2007: "Winning by a Neck…" pp .62-78; 5 Oct. 2008 some language corrections and a brief comment on Brown et al. 2007: "Extensive population genetic structure in the giraffe" on p. 79. The Evolution of the Long-Necked Giraffe (Giraffa camelopardalis L.) What do we really know? (Part 2) As for Part 1, see http://www.weloennig.de/Giraffe.pdf Some Questions, Facts and Quotations to Supplement Part 1 Repetitio est mater studiorum –Repetition is the best teacher (literally: the mother of studies) Summary Introduction: the story which is commonly taught in high schools about the evolution of the long- necked giraffe by natural selection (feeding-competition-hypothesis) fails to explain, among other things, the size differences between males and females. Giraffe cows are up to 1.5 meters shorter than the giraffe bulls, not to mention the offspring. The wide migration range of the giraffe and the low heights of the most common plants in their diet likewise argue against the dominant selection hypothesis. Now to the main points: 1) The fossil „links“, which according to the theory should appear successively and replace each other, usually exist simultaneously for long periods of time. 2) Evolutionary derivations based on similarities rely on circular reasoning (to refer once more to Kuhn's statement) 3) The giraffe has eight cervical vertebrae. Although the 8th vertebra displays almost all the characteristics of a neck vertebra, as an exception to the rule the first rib pair is attached there. 4) The origin of the long-necked giraffe by a macromutation is, due to the many synorganized structures, extremely improbable. 5) Sexual selection also lacks a mutational basis and, what is more, is frequently in conflict with natural selection („head clubbing“ is probably „a consequence of a long neck and not a cause“; see also Michell et al. 2009). 6) In contrast to the thus-far proposed naturalistic hypotheses, the intelligent design theory is basically testable. 7) The long-necked giraffes possibly all belong to the same basic type inasmuch as 8) a gradual evolution from the short-necked to the long-necked giraffe is ruled out by the duplication of a neck vertebra and the loss of a thoracic vertebra. 9) Chance mutations are principally not sufficient to explain the origin of the long-necked giraffe. 10) The intelligent design theory offers an adequate and satisfying solution to the problems and points to numerous „old“ and new research projects. 11) Mitchell and Skinner present a good analysis of the selectionist problem; however, their phylogenetic hypotheses presuppose the correctness of the synthetic evolutionary theory, and their claims of „intermediate forms“ are unproven. Contents Introduction: Is the Darwinian theory as taught in high schools in harmony with Page 1) the sexual dimorphism, 2) the body size of the young, 3) migration range, as well as 4) the heights of the plants in the giraffe’s diet?…………………………………2 1) Many species and genera of Giraffidae appear in the fossil record practically simultaneously, and the presumed ancestors co-existed millions of years together with their „more evolved“descendents……………….……………………………………..6 2) By evolutionary presuppositions a line of descent can almost always be postulated from a large variety of forms….…………………………………………….11 3) Number of neck vertebrae: why it is so hard to count to eight in the giraffe’s neck……….13 4) The question of causes (I): Macromutations – possibilities and limitations………………..18 2 5) The question of causes (II): Further hypotheses on the origin of the long-necked giraffe….20 6) The question of causes (III): Is intelligent design testable and falsifiable?......……………..22 7) Species concepts and basic types……………………………………………………………23 8) Supplementary question: In view of the duplication of a neck vertebra, is a continuous series of intermediate forms possible at all?.................……………………...…23 9) The question of chance (résumé)……………………………………………………………25 10) „Old“ and completely new research projects as deduced from the ID theory……...…….…25 11) Mitchell and Skinner…………………………………………………………………..….…28 12) Concluding remarks…………………………………………………………………………48 13) Acknowledgements and Notes………………………………………………………………49 14) Appendix (A note on the paper by Elissa Z. Cameron and Johan T. du Toit (2007): "Winning by a Neck: Tall Giraffes Avoid Competing with Shorter Browsers.")……….… .62 15) References …………………………………………………………………………………..77 Introduction to Part 2 Is the Darwinian Theory as taught in high schools in harmony with (1) the sexual dimorphism, (2) the body size of the young or (3) migration range as well as (4) the heights of the plants in the giraffe’s diet? When one does a Google search on „Giraffe“ and „Evolution“, the first result listed (thus the most frequently visited site)* briefly presents the theories of Lamark and Darwin on giraffe evolution. The authors are Marzena Franek, Anne-Kathrin Johannsmeier, Mara Jung, Susana Santos and Anne-Kristin Schwarz from the Gymnasium Meschede (2001). Lamarck’s theory is said to be refuted by the fact that „acquired characteristics are not inherited.“ Darwin’s theory is presented as the correct one: „In one generation of giraffes there is, by chance, an animal whose neck is longer than those of the other animals. This one survives, since it has a clear advantage in reaching higher leaves. This animal has sufficient nutrition to survive and multiply. In following generations several giraffes with longer necks arise, who have inherited the trait. Over many generations, longer necked giraffes continually made their way in life, and so today’s form developed.“ The following figure serves to illustrate the thesis in the textbook Evolution, Materialien für die Sekundarstufe II, Biologie, 1999, p. 15 by Peter Hoff, Wolfgang Miram and Andreas Paul (Schroedel-Verlag, Hannover): ______ *Repeatedly checked, last on 2 March 2007. 3 One of the most noble and important goals of school education should consist of helping young people learn to be critical thinkers, and to give them the ability to make reasoned judgements. Considering this question in connection with giraffe origins, one should cite, above all, the decisive fact that the giraffe cows are, on average, at least a full meter shorter than giraffe bulls, not to mention the much shorter offspring. „The normal heights at birth oscillates between 170 and 190 cm.“ – I. Krumbiegel 1971, p. 61. „The tallest giraffe, from Kenya and undoubtedly a male, measured 5.88 meters…the largest female, from northern Kalahari, measured 5.17 meters…“ – Dagg and Foster 1982, p. 71; also among captive giraffes we find a difference of some 1.5 m (according to Fig. 6-2 of the same work, likewise p. 71). Since on the next page the authors estimate the average difference at some 1m, this estimate may be somewhat too cautious. If the mothers, in competition with the fathers, do not have anything to browse, they cannot nurse their offspring anymore (the young animals „may suck for up to two years, but they supplement the milk with solids at about one month. Perhaps they need relatively little milk because of the high nutritional value of the acacia tips they eat.“ – Dagg and Foster 1982, p. 138; when almost grown, they are 3 ½ to 4 years old – Sherr 1997, p. 70). Although the young animals themselves begin to graze after only a few weeks, neither they nor their mothers would have a chance to survive under the conditions assumed above. According to this figure, only the one mutant animal would survive, and thus the population would die out instead of further evolving and becoming taller (C. Pincher already presented this problem in a Nature Article of 1949 and other researchers did so independently of him). Doesn’t such an „ugly fact“ – as Huxley once expressed it – indeed call into question the entire Darwinian explanation of giraffe evolution? (“The great tragedy of Science – the slaying of a beautiful hypothesis by an ugly fact" Huxley 1870, but there are further “ugly facts”—see below.) Why then is such a minor but decisive fact, which could easily be conveyed in a biology lesson, consistently left out of almost all textbooks and school instructions? Could it be that many evolutionary theorists prefer to impart evolution as a fact rather than to teach critical thinking? James Perloff comments the question of the origin of the giraffe as follows (2003, pp. 54/55, colored boldface in the text, here and in the following quotes, are mine): “Did giraffes really develop long necks because they lived around high vegetation, causing the extinction of shorter-necked giraffes? How then did young giraffes survive? Isn't it more likely that, facing such an environment, giraffes would have simply migrated to where food was more accessible? Colin Patterson of the British Museum of Natural History noted: It is easy enough to make up stories of how one form gave rise to another, and to find reasons why the stages should be favoured by natural selection. But such stories are not part of science, for there is no way of putting them to the test. Gould et al. wrote in Paleobiology: Paleontologists (and evolutionary biologists in general) are famous for their facility in devising plausible stories; but they often forget that plausible stories need not be true. And I again quote France's Pierre-Paul Grassé: Today, our duty is to destroy the myth of evolution, considered as a simple, understood, and explained phenomenon which keeps rapidly unfolding before us. Biologists must be encouraged to think about the 4 weaknesses of the interpretations and extrapolations that theoreticians put forward or lay down as established truths. The deceit is sometimes unconscious, but not always, since some people… purposely overlook reality and refuse to acknowledge the inadequacies and the falsity of their beliefs.