Experimental studies on the origins of diversity

点击翻译按钮获取中文摘要

This research program addresses one of the central problems in biology: the origin of diversity. The bulk of existing theory concerns the conditions for its maintenance, given that it already exists. My goal is to identify the factors responsible for generating diversity in the first place. I use microbial systems to study the origins of diversity in two contexts. The first is adaptive radiation - the rapid diversification of a lineage into a range of ecologically and phenotypically distinct niche specialists - of which the Galapagos finches and African rift lake cichlids are hallmark examples. We study adaptive radiation in the laboratory using the soil bacterium Pseudomonas fluorescens. Our aim is to understand the mechanisms governing the rate and extent of diversification. The second is the process that underlies diversification itself, adaptation. Our understanding of adaptation has not, until recently, moved much past Darwin's original idea that natural selection is the mechanism responsible. Our work aims to test the most compelling predictions of the increasingly sophisticated theory of adaptation that has developed over the past 10 years. We use the filamentous fungus Aspergillus nidulans for this work as it has a number of unique features that allow us to document adaptive evolution in the laboratory and tease apart the underlying genetic changes responsible. My lab offers outstanding opportunities for training in experimental evolution and allied fields (experimental design, microbiology) and I maintain close links with collaborators who provide complementary expertise for training in quantitative genetics, statistics, modeling and microbial genetics. This work makes some of the oldest and most fundamental problems in biology accessible to experimental research for the first time. I expect the results to be of wide and general interest, contributing to basic knowledge in evolution as well as more applied problems in medicine and conservation biology.