The human body is a machine whose many parts – from the microscopic details of our cells to our limbs, eyes, liver and brain – have been assembled in fits and starts over the 4 billion years of our history.
But scientists are still puzzling over why we evolved into this particular form. Why do humans uniquely have a chin, for example? And why, relative to body weight, is a human testicle triple the size of a gorilla’s but a fifth of that of a chimpanzee?
Lets put it this way: As with several other features of the human body, science has not yet found the evolutionary reason.
It is not that long ago when scientists wondered about the existence of the appendix. Before antibiotics and surgery, an estimated 5-10% of the population died of appendicitis, so there was an immense evolutionary pressure to get rid of it. But it was still there, leaving scientist baffled until they found out how important the appendix is for survival.
