Select to expand quote
Ian K said.. Mr Milk said..
When I was about 14 the PE teacher at my school pointed out to the class that humans are the only animal that walks and runs on our heels. Every other animal is up on their toes.
On flat ground maybe. But for how long in our evolution have we had flat ground to run on? On a natural surface, (apart from a beach at low tide maybe) every step would be different, on not too many steps would you choose to land on your heel. Test yourself out, find a rough bit of turf to run over.
I would hazard a guess that says that for most of our evolution we have had flat ground to run about on. It is our preferred environment. By standing, we have elevated our eyes to the same height as a much bigger animal. There is no real advantage to having a higher point of view if the ground is not relatively flat. And we are also persistence hunters, which is a damn sight easier to do on flat ground.
Just because hominid fossils tend to be found where they were buried by sedimentation you can't say that was where the hominids were spending most of their time. All you can say is that the environment was better for preservation of remains in those areas.
Most of the world is fairly flat, after all.