• Question: Is the human brain still evolving?

    Asked by zahy4932 to Ben, James, Jen, Michael, Susanna on 13 Mar 2013.
    • Photo: Jen Todd Jones

      Jen Todd Jones answered on 13 Mar 2013:

      All living creatures are subject to evolution and it happens with every new generation. For humans this does mean we are still evolving, and therefore the brain is still evolving, but to see any huge changes would take many many years – longer than we could live! There is an argument that with all of the modern medicines humans no longer evolve the same way because those that would die because of genetic probems or illnesses are being kept alive – what does it mean for their genes?

    • Photo: Ben Brilot

      Ben Brilot answered on 13 Mar 2013:

      There’s actually a big debate happening at the moment about whether humans are evolving at all right now. For evolution to happen there needs to be some difference between people which causes some individuals to be able to have more children than others. So say some people have slightly bigger brains, and that means they survive better, earn more money and can raise more children than people with smaller brains. Then on average the children of the next generation would have bigger brains. That would be evolution.

      Some people argue that in developed societies there is very little variation in how many children different people are having: we’re all having many fewer children than our ancestors would have done (i.e. around 2-3, compared to up to 20 only a couple of centuries ago). So they say that there just isn’t enough variation in family size for evolution to work. In other words, if everyone has more or less the same number of children, then evolution grinds to a halt. But, that argument only works in developed countries with low birth rates (like britain and the usa). For everywhere else, like Jen says, evolution works so slowly that changes might be happening, but they’d be happening so slowly that it’d be very hard to tell.

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