Post-glacial phylogeography of W. smithii

The distinction between model and non-model organisms is becoming increasingly blurred as high throughput, second generation sequencing approaches are being applied to organisms based on their interesting ecological, physiological, developmental or reproductive properties and not the depth of genetic information available for them. Herein, we present a low-cost and labor-effective approach to phylogeography that does not require an any a priori development of genomic resources sequenced genome or EST library. Phylogeography and phylogenetics have recently benefited from genome-wide SNP detection methods to show evolutionary patterns among taxa. The limiting step in the applicability of multi-locus datasets has been generating the genetic markers that are useful at finer scales of genetic divergence among taxa or populations. The novel use of restriction-site associated DNA (RAD) tags reveals heretofore unresolved genetic structure and direction of evolution in the pitcher-plant mosquito, Wyeomyia smithii, from a southern Appalachian Mountain refugium following recession of the Laurentide Ice Sheet commencing some 19-22,000 years B.P. The RAD-Tag approach can be used not only to elucidate fine-scale patterns of phylogeography as in W. smithii, but also to identify cryptic species or incipient speciation and genome-wide variation in natural populations.