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Science Frontiers ONLINE No. 19: Jan-Feb 1982 |
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African Fossil Sequences Support Punctuated Evolution
East of Lake Turkana, in northern Kenya, the geologist finds exceptionally fine sequences of fossil molluscs in old lake deposits. Williamson has scrutinized the distribution of some 190 faunas with high stratigraphic resolution; that is, he believes he has been able to sketch for the first evolutionary events on a fine time scale. Williamson underlines three important observations:
(1) Species seemed to arise suddenly, as predicted by the "punctuated evolution" model; (2) The formation of new species was accompanied by marked developmental instability in the transitional forms; and (3) All lineages were morphologically stable for long periods -- they did not change form!
The biological implications of this important study are summarized in the preceding item.
(Williamson, P.G.; "Palaeontological Documentation in Cenozoic Molluscs from Turkana Basin," Nature, 293:437, 1981.)
Comment. Evolutionists have often bewailed the obvious lack of transitional forms (missing links) in the stratigraphic record. According to Williamson's results, transitional forms would be few in number and display considerable morphological instability. In essence, this means that missing links may not exist in a practical sense. If this is true, one wonders whether those famous evolutionary family trees in all the textbooks, such as that of the horse, are really misleading.
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