Body Shape Divergence Among Wild and Experimental Populations of White Sands Pupfish (Cyprinodon Tularosa)

Abstract

Reports of contemporary evolution have become ubiquitous, but replicated studies of phenotypic divergence for wild populations are exceptionally rare. In 2001, a series of experimental populations were established to replicate a historic translocation event that led to a case of contemporary body shape evolution in the White Sands pupfish. Using landmark-based geometric morphometric techniques I examined phenotypic variation for seven of these populations, and two wild populations over a 5 year period (5-10 generations) in the field. Significant body shape divergence was observed, but divergence patterns were not parallel, suggesting that the ponds were ecologically dissimilar. Considerable body shape variation found among populations suggests that the observed divergence maybe governed by temporal environmental variance. In this study, body shape variation was correlated with population density. These data suggest that habitat intrinsic factors or unmeasured habitat features may have strong affects on body shape, warranting continuous monitoring of recently translocated fishes.