Polymorphism as a buffer against climate fluctuations

University Of Iowa, Iowa City IA

Investigators

Abstract

The cold conditions of winter 2009-10 throughout the southern US offer a rare opportunity to assess the immediate biological impacts of extreme climate fluctuation. This project will document the effects of the extremely cold winter on Drosophila americana, a fly species native to North America and distributed over a broad latitudinal range. Previous studies of this species reveal polymorphisms in genes and traits that allow persistence in time of extreme temperatures, and these genotypes and phenotypes differentiate the extreme northern and southern populations. This study will assess genotypic and phenotypic variation in southern populations to test whether polymorphisms characteristic of northern populations have a higher prevalence immediately following an extremely cold winter. Many features of the environment vary predictably in space and time, such as seasonal climate gradients in temperate regions. Organisms adapt to local conditions, yet day-to-day and year-to-year fluctuations occur as a consequence of weather systems. Genetic variation within species may play an important role in buffering populations against these fluctuations. This project will measure the immediate changes in the genetic and adaptive trait composition of populations following an extreme climatic event. The project will contribute to improved understanding of the capacity for genetic variation to buffer against climatic extremes, which is an important aspect of adaptation and persistence of species persistence as global climate and weather change.