Population genetics of the endangered Mitchell's satyr butterfly

The Mitchell's satyr butterfly, Neonympha mitchellii mitchellii, is a federally endangered species found in Southern Michigan and Northern Indiana. We describe the population genetic structure of this butterfly using multiple nuclear markers, both protein coding and anonymous loci. These markers were analyzed using a variety of methods on several software packages. All analyses report that the effective population size of N. m. mitchellii is significantly smaller than the known population estimates, indicating that this species passed through a genetic bottleneck in it's past. The estimated effective population size for the species is at least three orders of magnitude smaller than the estimated population sizes, indicating that a few individuals have contributed disproportionatly to the genetic diversity we observe today. Coalescent based estimates indicate that this bottleneck occurred within the past 15,000 years, but this estimate may be biased by the presence of the reproductive bacterium Wolbachia pipientis, the presence or which favors certain genotypes over others. These data provide the first evidence that this species has undergone a genetic bottleneck and these data may help conservation managers as they plan future recovery efforts.