Genetic variation at nuclear loci fails to distinguish two morphologically distinct species of Aquilegia.

• Main Authors: Elizabeth A Cooper, Justen B Whittall, Scott A Hodges, Magnus Nordborg
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2010-01-01
• Series: PLoS ONE
• Online Access: https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/20098727/?tool=EBI

Aquilegia formosa and pubescens are two closely related species belonging to the columbine genus. Despite their morphological and ecological differences, previous studies have revealed a large degree of intercompatibility, as well as little sequence divergence between these two taxa. We compared the inter- and intraspecific patterns of variation for 9 nuclear loci, and found that the two species were practically indistinguishable at the level of DNA sequence polymorphism, indicating either very recent speciation or continued gene flow. As a comparison, we also analyzed variation at two loci across 30 other Aquilegia taxa; this revealed slightly more differentiation among taxa, which seemed best explained by geographic distance. By contrast, we found no evidence for isolation by distance on a more local geographic scale. We conclude that the extremely low levels of genetic differentiation between A. formosa and A. pubescens at neutral loci will facilitate future genome-wide scans for speciation genes.