Genetic relationship of wood and plains bison based on restriction fragment length polymorphisms

To evaluate the genetic relationship within and between wood and plains bison of Elk Island National Park, genomic DNA samples were screened for restriction fragment length polymorphisms (RFLP) with cDNA probes for growth hormone, growth hormone releasing factor, somatostatin, and insulin-like growth factor-1. Of the 28 fragments identified, two revealed RFLPs, both of which were associated with the growth hormone releasing factor locus. The observed frequencies of the polymorphic sites did not differ from a Hardy–Weinberg distribution in either population, which is indicative of random mating populations. The contingency χ2 tests for homogeneity indicate that the fragment frequencies of the polymorphic restriction sites differ significantly (P = 0.00) between the wood and plains bison. The number of net nucleotide substitutions between the two populations was 0.0007, indicative of a recent divergence. Conversion of the bison nucleotide divergence results in a relative protein divergence of 0.007 to 0.018. This converted divergence corresponds closely to the divergence reported for other geographically isolated populations; thus, this preliminary analysis suggests the bison have at least reached the stage of geographic isolation in their evolutionary divergence.