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Breaking a tropical taboo

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Science  24 Jul 2015:
Vol. 349, Issue 6246, pp. 370-371
DOI: 10.1126/science.349.6246.370

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Summary

Researchers have had stunning success analyzing ancient DNA from samples from northern latitudes. But much of the world“s biodiversity, including that in the human family tree, evolved in the tropics, where hot, moist conditions can attack fragile DNA. DNA is a notoriously weak molecule, vulnerable to water or oxygen that can rip apart its chemical bonds. Chemical processes can wreak havoc, chopping DNA into tiny strands, sometimes only a few bases long. A severely degraded sample is little more than alphabet soup. So for decades scientists have assumed that the only place to find viable ancient DNA was in cold, dry environments. But now a handful of researchers are trying to find places, such as the interior of caves, where ancient DNA can survive the tropical assault and so answer questions that once seemed beyond its ken.