Research project: Defining evolutionary stability in south-eastern Australian marine and estuarine Mollusca
- Start date:
- New South Wales Environmental Trust
Change is certain in a biological system. How do humans, as a major current cause of that change, modify our impact on the environment so that we cause as little distortion as possible to natural evolutionary processes?
To answer this question we need to understand the current status of the studied system (and possibly, how it has changed in the past) sufficiently well to predict how it would be likely to change in the future in the absence of anthropogenic effects. In the case of the coastal ecosystems of New South Wales and southeastern Australia, we need to know the geographic patterns of genetic variation and how these are changing in contemporary environments, the levels of connectivity between populations and how these are affected by physical barriers over recent and historical time, and what selective forces, either natural or anthropogenic are being applied.
This program is concentrated on bivalves and gastropods and has begun with surveys of the geographic variation in DNA sequences in the snails of the estuarine genus Tatea and the intertidal Austrocochlea 'constricta' group and two bivalve genera Brachidontes and Xenostrobus. Other estuarine species are also being investigated to determine the generality of the Tatea pattern of very wide taxon distributions with little genetic structure between regions. A start has been made on the possibility of using shell elemental compositions as an indicator of provenance and potentially gene flow. We are studying current taxon distributions in comparison with museum records to determine if there has been a shift in the ranges of marine species in the historically-recent past.
Dr Don Colgan , Principal Research Scientist