Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Evidence for genetic adaptation to pollution (#503)

Alessandra AL Loria 1 , Melania MEC Cristescu 1 , Andrew AG Gonzalez 1
  1. McGill University, Montreal, QUEBEC, Canada

Adaptation to pollution has been studied intensively since the first observations of heavy metal tolerance in plants a few decades ago. In order to document micro-evolutionary changes and to fully demonstrate the occurrence of adaptation, researchers should, ideally, show evidence of a phenotypic change (i.e. resistance) with an underlying genetic basis, and a response to selection for tolerance to pollution. Moreover, it should be proven that the population has a positive growth rate. These aspects of the adaptive process can be considered evidentiary criteria for demonstrating adaptation and have been already used in relation to climate change. The purpose of this semi-quantitative review was to assess how well past studies meet these criteria and thus to provide a broad perspective of the extent of knowledge that we have on each step of the adaptive process in relation to soil and water pollution. We reviewed 253 articles published between 1992 and 2014 by searching genetic adaptation to pollution and micro-evolution AND pollution OR contaminants that focused on invertebrates, vertebrates (fish and amphibians) plants and algae. The studies were classified based on the fulfillment of the criteria. We found that the most compelling pieces of evidence come from studies focused on phenotypic responses (53%) and to a lesser extent, from studies focused on selective processes (almost 30%). However, only 6.7% of the studies fulfilled the first three criteria and only 10% included measurements of population fitness in their investigations. This, together with other potential bias (i.e. publication bias) could lead to an overestimation of the adaptive potential of populations to persist in polluted environments. Our study emphasizes the need to increase the number of studies that look at more than one evidentiary criteria and to increase the number of studies at the population level embracing approaches that integrate demography, ecology and evolution.