First published in 1871, "The Descent of Man, and Selection in Relation to Sex" is a book by English naturalist Charles Darwin. In this volume, Darwin attempts to marry the theories of human evolution with evolutionary theory, exploring evolutionary ethics, evolutionary psychology, differences between sexes, differences between human races, and the relevance of the evolutionary theory to society. Contents include: "Principles Of Sexual Selection", "Secondary Sexual Characters In The Lower Classes Of The Animal Kingdom", "Secondary Sexual Characters Of Insects", "Insects, Continued.--ORDER Lepidoptera.", "Secondary Sexual Characters Of Fishes, Amphibians, And Reptiles", "Secondary Sexual Characters Of Birds", etc. This classic work is being republished now in a new edition complete with a specially-commissioned new biography of the author. Charles Robert Darwin (1809 - 1882) was an English geologist, naturalist, and biologist most famous for his contributions to the science of evolution and his book "On the Origin of Species" (1859).