Evolutionary responses to ecological change
We live during a period of unprecedented environmental change, when widespread habitat loss has caused steep declines in the abundance of even previously common species. Such rapid loss of biodiversity is occurring just when large populations and diverse communities are crucial to buffering biological responses to climate change, and while human consumption demands more and more output from these depleted ecosystems. For how long can global ecosystems sustain such losses and remain biologically productive? To what extent have evolutionary responses in these communities already buffered such losses, and for how long will they continue to do so? For more background, follow the links to the right:
Maximum rates of evolution in nature
Evolution can generate fundamental changes in the ecology and distribution of organisms, otherwise there would be no life on land, and no mammals in the ocean. However, such adaptation operates within ecological and genetic limits: at any one time all species have limited habitat distributions, and all species eventually become extinct. Such maximum rates of evolution are determined by the amount of genetic variance in fitness available in natural populations, and the demographic cost of sustaining phenotypic change. Our research tries to understand these evolutionary limits can buffer rapid environmental change using a combination of ecological fieldwork, quantitative genetics, population genetic and genomic analysis, and theoretical modelling. We are particularly interested in how abiotic and biotic limits to species’ distributions interact, and to what extent genetic evolution and speciation can affect these limits. We work on a wide range of organisms to quantify the nature and amount of genetic variance of fitness traits in natural populations, the pattern and rate of ecological change in space and time, the nature of ecological interactions between species, and to try to unravel the fitness consequences of recombination. Understanding how different species and ecosystems respond to ecological change under different conditions, and for how long they remain resilient to biodiversity loss is crucial for defining dangerous levels of global ecological change. We hope that our research will also guide policies to mitigate these effects, and to maximise evolutionary rates in natural populations.
Our main external collaborators
Prof Nick Barton and Dr Jitka Polechova (Institute of Science and Technology, Austria)Prof Mark Blows (University of Queensland)
Prof Roger Butlin (University of Sheffield)
Dr Chris Jiggins (University of Cambridge)
Prof Ary Hoffmann (University of Melbourne)
Dr Jason Kennington (University of Western Australia)
Dr Robert Wilson (University of Exeter)
Group members and projects
Dr Jon Bridle(Group Leader)
At species’ and population margins, limits to adaptation prevent expansion into novel environments, causing extinction. Such distributional limits occur either because selective gradients become too steep relative to migration between populations, or because marginal populations lack the genetic variation necessary for adaptation. The study of repeated altitudinal transects in the fruit fly Drosophila birchii presents a unique opportunity to distinguish between these hypotheses, and highlight the key ecological and genetic parameters that limit evolutionary potential in natural populations. We are using molecular analysis, field experiments, and quantitative genetic analysis to estimate gene flow, additive and non-additive variation in stress-related traits, and directly assess the consequences of genetic variation in fitness on adaptive divergence along repeated ecological transitions of varying steepness. Empirical estimates of key parameters will then be used to test the generality of current theoretical models for evolution at range margins.
Alan Reynolds (Research Assistant)
Lucia Aguila (Research Assistant )
Roseanne Guy (Research Assistant)
James Buckley (PhD student)
Testing for evolutionary change at expanding and contracting ecological margins of butterflies
Aditi Singh (MRes student)
Genetics of mating signals and speciation in Chorthippus grasshoppers
