Distinct morphologies and cloudy mitochondrial DNA: Divergence and incomplete lineage sorting of whitefish in a high desert mountain lake

Authors: Becky A. Miller, Derek D. Houston, Dennis K. Shiozawa, R. Paul Evans

Year: 2016 (xlviii)

Abstract

Evolutionary trajectories of fish species are impacted by the complex geologic and climatic events that influence the way organisms interact with their environment. The mountain whitefish (Prosopium williamsoni) is widely distributed throughout several western North American drainage basins. Relatives to the mountain whitefish are the Bear Lake whitefish (Prosopium abyssicola), Bonneville cisco (Prosopium gemmifer), and Bonneville whitefish (Prosopium spilonotus). All three are endemic to Bear Lake, which straddles the Utah and Idaho border near Wyoming. It is late Pleistocene in age, but some authors consider the Bonneville cisco to be a descendent of a Prosopium in Pliocene Lake Idaho. Mitochondrial DNA sequence data was used to evaluate range-wide genetic diversity of mountain whitefish and the Bear Lake relatives. Phylogenic analysis did not resolve relationships among drainage basins, although whitefish from some major drainage basins form well-resolved clades (e.g., Green River, Lahontan Basin, Missouri River). The three Prosopium species endemic to Bear Lake also exhibit incompletely resolved phylogenetic relationships, but this appears to be due to their relatively recent divergence in Bear Lake. They also exhibit incomplete lineage sorting. The Bear Lake endemic whitefish render P. williamsoni paraphyletic, thus calling into question the taxonomy of the group.