Local adaptation and speciation

Name of supervisor: Dr Rhonda R Snook

Key Words: physiology, reproductive isolation, thermal tolerance, evolution, genetics

Description of project: Environments change and organisms must respond to these changes by either migrating or evolving, or face extinction. Climate change has both direct effects, such as influencing physiological processes, and indirect effects such as selection on key traits influencing reproductive output. Changes in species’ ranges (migration) and phenologies (evolution) have been widely documented, but ignorance of what underlies the ability to adapt along an environmental gradient, particularly how underlying genetic structure, influences response across large geographic scales, remains scandalous. One type of genetic structure is chromosomal inversions in which gene order is rearranged. In some organisms, there is a correlation between chromosomal inversion polymorphisms and local adaptation, particularly along a temperature gradient. Likewise, such inversions have long been suggested to be important in speciation by causing pre - and post-zygotic reproductive isolation due to the locally adapted genes “captured” in the inversions. Genes are captured because inversions suppress recombination between alternative chromosomal arrangements and therefore can become linked with genes involved in both local adaptation and reproductive isolation.

Very few studies have addressed the role of chromosome inversions in both local adaptation and speciation. Here the PhD candidate will use established semi-natural populations of Drosophila subobscura, collected across a 30oC latitudinal gradient, to examine how chromosome structure contributes to thermal tolerance, reproductive performance, and reproductive isolation across the cline. The student will join the Snook lab and will be additionally supported by a large group of international researchers studying climate change, local adaptation and speciation.

To apply, please complete an online application form which can be found at www.shef.ac.uk/postgraduate/research/apply/applying
The closing date is 15th January 2013