Contrasting patterns of Organismal versus Molecular Evolution

    The contrast between biological evolution and molecular evolution since the divergence of the human and chimpanzee lineages. A: More biological change has taken place in the human lineage (y) than in the chimpanzee lineages (x), such that they are traditionally classified in separate families (Hominidae and Pongidae, respectively). B: Protein and nucleic acid evidence indicates that  essentially identical amounts of genetic change have occurred in chimpanzee genes (w) as in human genes (z) since their common ancestor. C: The amount of genetic differences between chimps and humans is less than that between morphologically-identical sibling species of Drosophila. One unit of genetic distance corresponds roughly to an average difference of one amino acid substitution per protein. (Wilson 1976, from King and Wilson, 1975)


Text material © 2010 by Steven M. Carr