Anthropogenic disturbance is widespread, creating conservation and economic concerns and receiving much attention in applied research. While usually considered in a (rightly so) negative context, these stresses create a unique arena for the basic study of rapid evolution and ecological dynamics. In this project we combine evolutionary and eco-toxicological approaches with the latest genomic technologies (next-generation-sequencing, NGS) and computational biology to test the biological effects of anthropogenic change, specifically pollution, using Mediterranean mussel (Mytilus galloprovincialis) populations along the Croatian Adriatic coast. The project consists of four discrete, inter-related components. First, we use chemical and eco-toxicological analyses to quantify a gradient of pollution across fifteen populations, ranging from pristine waters to highly polluted harbours, followed by further ecological characterisation of the sites. Second, we use genotyping-by-sequencing (GBS) to identify single nucleotide variant (SNV) patterns of genetic differentiation across the genome. Using a Bayesian population genomic framework we quantify genetic structure, infer gene flow and population sizes, and identify exceptionally differentiated ‘outlier’ loci implicated in divergent adaptation. The results will test whether pollution affects genetic structure and drives rapid evolution. Third, we combine transplant experiments and mesocosm exposures, with genome wide association scans to identify associations between genotype, phenotype, and fitness, to quantify the genetic architecture of fitness variation and test whether regions differing strongly between populations are the same as those associated with fitness of individuals. Finally, we use bisulphate sequencing to examine DNA methylation patterns to test whether epigenetic profiles changes, as well as alterations in DNA sequence, contribute to rapid adaptation to pollution.
This project is funded by the Unity through Knowledge Fund (UKF – PI’s Patrik Nosil and Göran Klobučar) and is a collaboration between The University of Sheffield and Zagreb University. The project is being jointly led in Croatia by Anamaria Stambuk, and in Sheffield by me.