Thursday, September 20, 2012
Studies slow the human DNA clock
The story of human ancestors used to be writ only in bones and tools, but since the 1960s DNA has given its own version of events. Some results were revelatory, such as when DNA studies showed that all modern humans descended from ancestors who lived in Africa more than 100,000 years ago. Others were baffling, suggesting that key events in human evolution happened at times that flatly contradicted the archaeology.
Now archaeologists and geneticists are beginning to tell the same story, thanks to improved estimates of DNA’s mutation rate — the molecular clock that underpins genetic dating1–4. “It’s incredibly vindicating to finally have some reconciliation between genetics and archaeology,” says Jeff Rose, an archaeologist at the University of Birmingham, UK. Archaeologists and geneticists may now be able to tackle nuanced questions about human history with greater confidence in one another’s data. “They do have to agree,” says Aylwyn Scally, an evolutionary genomicist at the Wellcome Trust Sanger Institute in Hinxton, UK. “There was a real story.”
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