The Descent of Man

Twelve years after On the Origin of Species, Darwin addressed the question his first book had carefully avoided: where human beings come from. He argues that we descend from earlier primates, traces our mental and moral faculties to animal origins, and suggests Africa as the probable cradle of humanity. Much of the book is about sexual selection, the competition for mates that explains the peacock's tail and the songs of birds.

Published in 1871, it caused as much debate as the Origin, and some of its views on race and on women belong very much to Victorian England. Its central arguments, however, still shape biology. Read it with On the Origin of Species and The Expression of the Emotions.

Charles Darwin (1809–1882) left medical school in Edinburgh because he could not bear to watch operations, and studied at Cambridge to become a clergyman. Instead, at twenty-two, he joined the five-year voyage of HMS Beagle, described in The Voyage of the Beagle, which gave him the observations of a lifetime.

Back in England he worked for twenty years at his country home in Kent before a letter from the naturalist Alfred Russel Wallace, who had reached the same idea, pushed him to publish On the Origin of Species in 1859. He went on to write The Descent of Man and books on barnacles, orchids and earthworms, and was buried in Westminster Abbey.