Even before Darwin, biologists recognized that species that looked quite different as adults often had close similarities as developing embryos. Many four -- legged animals go through embryonic stages that have similar features -- gill arches, a notochord, segmentation, and paddle-like limb buds -- as they develop into different adults. To Darwin, the embryonic resemblances were strong support for the theory of evolution.
One of Darwin's contemporaries, German biologist Ernst Haeckel, summed up the argument in a famous, pithy statement: "Ontogeny recapitulates phylogeny." That is to say, in the process of development, an individual passes through the adult forms of all its ancestors. So, Haeckel proposed, by examining the development of an embryo you could read its entire evolutionary history in the transition from one stage to another. In fact, this isn't strictly true, and the drawings Haeckel made exaggerated the embryonic similarities between species.
Tags: Evolution Darwin AIG Kent Hovind Ken Hamm Genetics Embryo
