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Science Frontiers ONLINE No. 123: May-Jun 1999 |
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Throwing Sand In The Gears Of Molecular Clocks
African Eve Gets a Lot Older. It is widely accepted as fact that all women are de-scended from an African "Eve" who lived between 100,000 and 200,000 years ago. This conclusion was based upon mtDNA (mitochondrial DNA) studies that assume that mtDNA is inherited only from mothers. This assumption has been repeated so often that few ever question it. However, two recent studies seem to show that some paternal mtDNA actually does get into eggs and recombines with maternal mtDNA. This unexpected invasion makes the mtDNA clock run more slowly. So, African Eve, if she ever existed, is probably twice as old as originally thought.
(Day, Michael; "All about Eve...," New Scientist, p. 4, March 13, 1999.)
Maybe There Were Two Eves! Not only has African Eve aged precipitously but there may have been a non-African Eve, too. J. Hey and E. Harris, at Rutgers, have presented data suggesting that the famous African Eve was the mother of only modern sub-Saharan Africans. Everyone else seems to have descended from an entirely different Eve. These data, if confirmed, demolish the African Eve theory and support the often-reviled multiregional theory of humans origins.
(Pennisi, Elizabeth; "Genetic Study Shakes Up Out of Africa Theory," Science, 283:1828, 1999. Bower, B.; "DNA Data Yield New Human-Origins View," Science News, 155:181, 1999.)
Genetic Clocks Are Fickle. mtDNA clocks have implied that modern birds and mammals were contemporaneous with dinosaurs, and that some animals evolved millions of years before their first fossils. For good reasons, evolutionists are becoming wary about these molecular clocks. It is fast becoming obvious that:
"Clocks tick at different rates in different lineages and at different times. And new work on the biology of mitochondria suggests that their evolution may be more complicated than researchers had suspected."
(Strauss, Evelyn; "Can Mitochondrial Clocks Keep Time?" Science, 283:1435, 1999.)