Neanderthals shared about 99.84 per cent of their DNA with us

From Into the mind of a Neanderthal by Thomas Wynn and Frederick L. Coolidge.

So what was it like to be a Neanderthal? Did they feel the same way we do? Did they fall in love? Have a bad day? Palaeoanthropologists now know a great deal about these ice-age Europeans who flourished between 200,000 and 30,000 years ago. We know, for example, that Neanderthals shared about 99.84 per cent of their DNA with us, and that we and they evolved separately for several hundred thousand years. We also know Neanderthal brains were a bit larger than ours and were shaped a bit differently. And we know where they lived, what they ate and how they got it.

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As for the neighbourhood, the size and distribution of archaeological sites shows that Neanderthals spent their lives mostly in small groups of five to 10 individuals. Several such groups would come together briefly after especially successful hunts, suggesting that Neanderthals also belonged to larger communities but that they seldom made contact with people outside those groupings.

Many Neanderthal sites have rare pieces of high-quality stone from more distant sources (more than 100 kilometres), but not enough to indicate trade or even regular contact with other communities. A more likely scenario is that an adolescent boy or girl carried the material with them when they attached themselves to a new community. The small size of Neanderthal territories would have made some form of "marrying out" essential.