What was it like when the first descendants of the human race emerged?

STANDING on the Serengeti plains of East Africa, you can’t help but feel small. Mostly this is because, in the face of so much of the world all around you, you become acutely aware of your mortal insignificance. Everywhere you look there is no end to the grasslands and scattered shrub and baobab trees that sweep out to the horizon. Everything – mountains, gorges, clouds – shrinks. Smaller objects, like lions and wildebeests and zebra, can disappear altogether in the heat and the piddling ability of your eyes to pick out details in the things around you …

Walking seems simple enough, but it took a long time before we got there.

TRY swinging the same arm and leg when you walk--right leg, right arm together. It’s an awkward feeling. That’s because we never do it. When stepping forward with your right leg, you swing your left arm forward, and vice-versa. But why?