Sniffing Out The Truth
Are modern human beings really part Neanderthal? From their first discovery in the 1850s it was clear that these extinct hominids looked a lot like us but there were some clear differences. The heavy brow ridges and more robust skeleton seemed to separate them neatly from our own, more gracile ancestors, but the truth may be much more complicated. Now a new study released earlier this week (Nov 18th) is using a novel approach to address this question.
The discovery of apparent ‘hybrid‘ individuals with human and Neanderthal features has caused some researchers to suggest that we may have interbred. This conclusion is apparently supported by evidence from our genes, some of which have been traced to a Neanderthal ancestor. This raises a problem for biologists though, as the definition of a species is taken to be ‘a population of animals which can interbreed to produce fertile offspring’. This means donkeys and horses are still separate species despite being able to make mules but what about humans and Neanderthals? If we really have inherited some of our DNA from Neanderthals then we must have had fertile offspring but doesn’t this make us the same species?
A study published by the SUNY Downstate Medical Centre, New York, has focused on one key feature of Neanderthal anatomy in an effort to answer this question. They examined the noses, or rather nasal cavities, of fossil Neanderthals and compared them to modern humans. Today our noses are not just used to detect smells but also warm the air coming into our bodies and during the Ice Age this would have been particularly important. What these researchers found was that Neanderthals possessed an upper respiratory tract specially evolved to deal with cold climates but very different to that of any modern humans. This means they evolved quite separately and suggests that our species were actually quite distinct after all.
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