Electrophoretic Comparisons between Allopatric Populations of Five Australian Pseudomyine Rodents (Muridae)

Publisher Website
Google Scholar
Abstract
Allopatric populations of the pseudomyine rodents Pseudomys albocinereus, P. delicatulus, the P. nanus-P. gracilicaudatus complex, Zyzomys argurus and Mesembriomys gouldi were surveyed for electrophoretic variability of 14-17 red cell and plasma proteins. Few or no electrophoretic differences were found to parallel the chromosomal differences between populations of P. delicatulus, Z. argurus and M. gouldi. Populations of the P. nanus-P. gracilicaudatus complex fell into 2 groups defined both chromosomally and electrophoretically. The western form (P. nanus) extends from Western Australia into the Northern Territory while the eastern form (P. gracilicaudatus) occurs only along the east coast of Queensland and New South Wales. The biochemical differentiation between South Australian, Western Australian mainland and Bernier Island P. albacinereus parallels the chromosomal, morphological and breeding data, all of which indicate that the Western Australian mainland and Bernier Island forms belong to one species (P. albocinereus), while the South Australian form represents a distinct biological species (P. apodemoides). The relationship between electrophoretic variation and the biological species concept was explored using data from Drosophila and rodents. If 2 allopatric populations possess fixed electrophoretic differences at at least 15% of their loci, then it is highly probable that they belong to different biological species. Populations that differ by less than 15% of their loci need not necessarily belong to the same species especially if chromosomally they differ by several Robertsonian rearrangements.