Local adaptation for body color in Drosophila americana: commentary on Wittkopp et al.

摘要

Wittkopp et al. (2011) report clinal variation of cuticle coloration among populations of Dmsophila americana despite the high levels of gene flow across collection sites, providing evidence for local (darwinian) adaptation of body coloration in this species. Several mechanisms have been proposed to explain the evolutionary patterns of pigment variation in ectothermic organisms such as D. americana. For example, the occurrence of dark-pigmented populations of several Drosophila spp. has been associated with dry environments (for example, Parkash et ah, 2010). This relationship represents the main hypothesis tested by Wittkopp et al. (2011), and the authors conclude that pigmentation and desiccation resistance are not unequivocally linked among the populations investigated. However, other climatic explanations that are not addressed in the study may explain these color patterns.