Research Seminar - Hawkesbury Institute for the Environment

To what extent can organisms counter the negative effects of climate change through evolutionary adaptation or plasticity?

These possibilities are often overlooked in models predicting the impact of global climate change on biodiversity even though there is increasing evidence that genetic and plastic changes can have an impact on fitness in natural populations. The genetic basis of climate change adaptation can be investigated through a variety of observational and experimental approaches, such as sampling across clines, phylogenetically-informed species comparisons, artificial evolution experiments, and 'resurrection' studies. These approaches can be combined with techniques like association and mapping analyses, genome scans, comparative genomics and transcription profiling.

In my group we have been trying to understand the potential for genetic and plastic adaptation by investigating climate gradients spanning several hundred meters of elevation in multiple regions in the Victorian Alps, and much longer gradients spanning several thousand kilometres along eastern Australia. The Alps work is focussed mostly on forbs and grasses, the longer gradient on widespread/restricted Drosophila species. I'll describe some of the results emerging from these studies. I show how the Drosophila clines are being used to identify several genes involved in climate adaptation and also how they are also being used to assess the potential role of natural genetic variation in candidate genes identified from other types of studies.

In some cases it appears that the genetic basis of adaptive clinal variation is relatively simple, as illustrated by pigmentation patterns in flies. In other cases it appears to be more complicated, but we nevertheless suspect that signatures of current adaptability and past adaptation will still emerge from genomic comparisons of populations and species occupying different climate niches. I show how the alpine plant work is pointing to the potential importance of hybridization in generating variability and the contrasting patterns of plasticity and genetic variation in adaptive responses of different species to elevation gradients. I use some of these results to argue that short term measures need to be put into place now to increase the evolutionary resilience of our plants and animals, and I illustrate how one approach might assist in building resilience in threatened species.

Further information about the HIE Seminar series and committee can be accessed via: http://www.uws.edu.au/hie/events_and_seminars