In this book, Jos Verhulst expands on the evolutionary theory first proposed by Louis Bolk. The theory is based on the premise that aspects of the individual creatures' development - from juveniles to adults - are also at work in animal evolution as a whole. Verhulst shows that, unlike other primates - who start out with a rather humanlike form but become, say, apes - humans retain their original fetal form. Standing Darwinism on its head, he argues that humans have not descended from apes, but rather that apes have evolved by diverging from a humanlike prototype. He also proposes that the gradually emerging human prototype is the driving force, and central trunk, of the evolutionary tree - the wellspring from which the animal world has sprung.

