• Hominoid phylogeny;
  • Molecular evolution


Molecular approaches to primate evolutionary relationships have been in use for 25 years. Recent advances in nucleic acid technology have permitted increasing resolution in assessing the topology and timing of primate phylogeny. The basics of these new approaches and their possibilities and limitations are set forth in reference to hominoid evolution. Specific reference is made to recent research involving DNA-DNA liquid hybridization, restriction mapping, and nucleic acid sequencing. These approaches are unanimous in establishing an African ape-human clade within the hominoids; orangutans share a more recent common ancestor with this clade than does the gibbon. Present data on the form of the tree uniting chimps, gorilla, and human are not compelling. Currently, it appears somewhat more likely that chimps and humans shared a most recent common ancestor, but a strong case can be made for a tree that joins chimp and gorilla. The tree uniting humans and gorillas cannot be disregarded. For present purposes, a trifurcation, though probably not literally correct, is a reasonable reconstruction. Molecular information is proving especially useful in setting the time frame for hominoid evolution as well as drastically limiting the number of trees that can be reasonably entertained. As the technology becomes more sophisticated, it can be hoped that the ability to discriminate between trees will increase. It will be necessary to maintain a continuing dialogue between morphological and molecular biologists to insure cross-fertilization of ideas about hominoid relations.