Found this online today @ http://stripe.colorado.edu/~am/Tuis.html concerning the genus Tui chubs (Siphateles)
"Freshwater organisms of the Great Basin in western North America are often restricted to small, isolated spring systems separated from other suitable habitats by vast expanses of inhospitable deserts and mountain ranges. A classic example of a species with a widespread and discontinuous distribution is the Tui chub, Siphateles sp.. We surveyed cytochrome b DNA sequence variation, microsatellite allele frequency variation, and morphological variation to evaluate the degree of differentiation between geographically isolated populations in Nevada. The cytochrome b data provide evidence for three genetically distinct groups estimated to have diverged sometime in the middle to late Pliocene, well in advance of paleohydrological predictions for middle or late Pleistocene divergence times. On the other hand, many of the currently geographically isolated populations share alleles for both the mitochondrial and microsatellite loci, suggesting that some populations were recently connected, probably during high pluvial lake stands in the middle to late Pleistocene. All of the populations surveyed for morphological features were significantly different. The combined analysis of molecular markers coupled with published morphological and paleohydrological studies suggest that the historical biogeography of Great Basin aquatic ecosystems is complex and involves overlaid cycles of dispersal, isolation, differentiation and extinction since the early Miocene. Our results support recognition of at least 3 or 4 distinct evolutionary significant units in Nevada."
Bernie May's lab has worked on the evolutionary genetics of Siphateles.
Phil Harris's studies of the evolution and genetics of fishes, including Siphateles. "
...This information can help piece together both the geological, climatological and biological puzzle that surround the present day abundance, distribution and isolation of species and subspecies of the genus Siphateles...
Posts
