• Question: how did apes turn in to humans.

    Asked by iamgod to Cesar, Emily, Jamie, Kate, Philippa on 13 Jun 2011. This question was also asked by dillonlancaster.
    • Photo: Philippa Demonte

      Philippa Demonte answered on 12 Jun 2011:

      Apes evolved into humans over a l-o-n-g period of time in order to adapt to their environment changing.

      There are many reasons for this happening, for example global warming / cooling and changes in the atmospheric gas content affecting plants and therefore the food available for animals to eat, or new predators coming into an animal’s environment which means that they have to find new ways to escape.

      Don’t quote me on this as I’m a geophysicist and not a biologist/zoologist, but I think the apes evolved because of the latter reason – they used to walk on all 4 limbs, but then needed to learn to walk/run on 2 legs and have 2 arms to climb trees to escape predators.

    • Photo: Kate Clancy

      Kate Clancy answered on 13 Jun 2011:

      Actually, slight correction… apes did not evolve into humans. We have a last common ancestor. Saying apes evolved into humans is like saying you evolved from your cousin Hal. If you go back a few generations, you figure out you share a grandmother, but you did not come from your cousin. See what I mean? 🙂

      So then the question is, why did humans evolve from the last common ancestor that we share with apes? And this is what human evolutionary biologists fight about at every conference I’ve ever attended. One thing most people agree on is the order of events: we got up on two legs, then our brains got bigger. So the first question is why we got up on two legs, the second why our brains are so big.

      Here are some things people fight about regarding the two legs thing: we needed to use our hands to gather food; two-legged long distance running is more efficient than four-legged running, which is good for having big home ranges; or maybe we wanted our hands free to bash in each other’s heads. Right now lots of people really like the running idea.

      Here are some hypotheses people have about the brain thing: we are a very social species and need big brains to store socially complex info; we aren’t very large bodied so needed big brains to outwit predators and become predators ourselves; there was a lot of fish and nuts in our diet and those oils and fats were particularly good for growing brains.

      What’s interesting about this is that it is clear that earlier in our lineage, when we had two legs but our brains weren’t really that big, we were already forming complex societies, had stone tool technologies, and even shared technology and culture among different hominin species.

      Did you know that there were at least five different species of hominins all living at the same time around three million years ago? And we have fossil evidence that they somehow communicated or shared information!

      It’s crazy to me that so many human ancestor species all lived at the same time, and maybe even in harmony. Same with humans and Neandertals tens of thousands of years ago. We like to say we beat them into extinction, but we have some of their DNA: we might have been quite friendly with them after all (cough cough).

    • Photo: Jamie Gallagher

      Jamie Gallagher answered on 13 Jun 2011:

      I agree with Kate on this one.
      I find it all very interesting. I love Neanderthals too, a real cousin of modern man. What a pity they didn’t stick around. But I digress.

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