USE OF RESTRICTION ENDONUCLEASES TO MEASURE MITOCHONDRIAL-DNA SEQUENCE RELATEDNESS IN NATURAL-POPULATIONS .2. MITOCHONDRIAL-DNA CLONES AND MATRIARCHAL PHYLOGENY WITHIN AND AMONG GEOGRAPHIC POPULATIONS OF THE POCKET GOPHER, GEOMYS-PINETIS

Restriction endonuclease assay of mitochondria DNA (mtDNA) and standard starch-gel electrophoresis of proteins encoded by nuclear genes were used to analyze phylogenetic relatedness among a large number of pocket gophers (G. pinetis) collected throughout the range of the species. The restriction analysis clearly distinguishes 2 populations within the species, an eastern and a western form, which differ by at least 3% in mtDNA sequence. Qualitative comparisons of the restriction phenotypes can also be used to identify mtDNA clones within each form. The mtDNA clones interconnect in a phylogenetic network which represents an estimate of matriarchal phylogeny for G. pinetis. Although the protein electrophoretic data also differentiate the eastern and western forms, the data are of limited usefulness in establishing relationships among more local subpopulations. The comparison between these 2 data sets suggests that restriction analysis of mtDNA is probably unequalled by other techniques currently available for determining phylogenetic relationships among conspecific organisms.