Are chimps almost human? Are we just smarter chimps? What does that oft-quoted 1.6% difference in DNA actually mean? As teams worldwide seek the genetic basis of our humanity, a complex picture is emerging. Small changes in key genes can cause big ones in brains, bodies and behaviour. We've changed profoundly since the chimp-human split.
Humans are the only mammals to walk on two, rather than four, legs. From an evolutionary perspective, this is an illogical development, as it slows us down. But here we are, suggesting there must have been something tremendous to gain from bipedalism.
