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Friday, September 09, 2005We tend to think of human beings as the end product of millions of years of evolution, but two new studies are showing that humanity still is a work in progress. I thought that was self-evident, both morally and biologically, but there's more: Researchers have documented two striking examples of how evolution is continuing to change our most defining organ -- the brain. The studies, published in the journal Science, detail evolutionary changes in two genes related to brain size. One of the genes, known as ASPM, evolved into a new form just 5,800 years ago. In the second gene, known as microcephalin, a new variant evolved 37,000 years ago. Well, I guess that's recent, in evolutionary terms. But how significant are those genes? They don't know: Although researchers know the two genes are related to brain size, it's unclear how evolutionary changes in those genes have affected the brain. It's possible the changes made brains larger, making people smarter. But it's also possible the genetic changes made brains smaller, thus making it easier for women to give birth to babies with smaller heads. Whatever. If history is any indication, our brains have been evolving for as long as we know, otherwise we'd all still be gathering nuts on the plains somewhere. posted by Sydney on 9/09/2005 08:49:00 AM 0 comments 0 Comments: |
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