Two hundred thousand years ago, human brains were substantially smaller than they are today. They’d been growing slowly for about three million years or so, but then abruptly there was a dramatic increase of about 30 per cent or so.
So what happened? Prof Colin Blakemore, a neurobiologist from Oxford University, believes that it’s all down to an individual named ‘Mitochondrial Eve’ who lived about 200,000 years ago.
His theory is that a dramatic and spontaneous mutation in the brain of Mitochondrial Eve, or one of her relatives, substantially boosted our brainpower. It brought us to a level that allowed us to come up with solutions to crises like droughts and climatic changes that would otherwise have killed us off. From there, natural selection did its work.
The upshot of this theory is that Homo sapiens is something of a genetic accident. It’s probably no surprise to learn that not everyone is on board with this idea, with most researchers believing that our intellectual abilities were gained through gradual evolution. But if Blakemore is correct, then perhaps we’ve only seen the start of what the human brain is capable.
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