Rob Dunn at the Smithsonian Magazine has an interesting article on the not-so-useful aspects of human anatomy that resulted from evolutionary history.
It starts with evidence that the mitochondria in our cells were once separate organisms and goes on to explain things like how the change from quadrupedal to bipedal, upright walking resulted in our S-shaped spine (and frequent backaches) and our unsupported intestines. It’s quite the interesting read.