Two more finds show spectacular stasis – the lack of evolution.
Echinoderms: A core from the North Sea shows fossils of echinoderms (a phylum including sea stars, sea urchins and sea cucumbers) doing just fine at an evolutionary date of 114 million years (early Cretaceous) – far earlier than previously supposed. European scientists said, “the evidence points to an early Mesozoic or older colonization of deep-sea habitats by the modern fauna.” This discovery causes another rethink: deep sea marine organisms are more resistant to presumed mass extinctions in the geological timeline than previously thought. From the abstract of their paper in PLoS ONE:
Our discovery provides the first key fossil evidence that a significant part of the modern deep-sea fauna is considerably older than previously assumed. As a consequence, most major paleoceanographic events had far less impact on the diversity of deep-sea faunas than has been implied. It also suggests that deep-sea biota are more resilient to extinction events than shallow-water forms, and that the unusual deep-sea environment, indeed, provides evolutionary stability which is very rarely punctuated on macroevolutionary time scales. (Thuy B, Gale AS, Kroh A, Kucera M, Numberger-Thuy LD, et al. (2012) Ancient Origin of the Modern Deep-Sea Fauna. PLoS ONE 7(10): e46913. doi:10.1371/journal.pone.0046913.)….
Continue Reading on crev.info