Berlin Highlights—Long-term Ecotoxicological Impact: Trans-generational Effects and Evolutionary Responses to Pollutants
Marie-Agnés Coutellec, INRA and Carlos Barata CSIC
The general objective of "Long-term Ecotoxicological Impact: Trans-generational Effects and Evolutionary Responses to Pollutants" was to address evolutionary and trans-generational impacts of pollutants, and to provide the SETAC community with a timely update on these emerging topics.
The long-term consequences of pollutants on natural populations are becoming increasingly more documented in the field of ecotoxicology. This growing corpus of knowledge is expected to contribute to the understanding of population responses to human-induced disturbance, and to their consequences at the ecosystem level. Moreover, it validates arguments for the incorporation of such impacts into future ecological risk assessment procedures.
Pollutants may cause direct alterations of DNA, or they may trigger micro-evolutionary processes such as adaptation, or interactions with other selective forces (fitness cost), random genetic drift, inbreeding and gene flow. Variation in sensitivity to pollutants between populations, or between lineages with various levels of phylogenetic divergence, demonstrates the critical need to consider genetic background in ecotoxicity testing, and to incorporate evolutionary concepts into ecological risk assessment. Among these, the concepts of adaptive potential and cost of adaptation seem to be the most promising. Theoretical formalization of the evolutionary component of community responses to pollutants is also expected to be highly relevant in this context.
Furthermore, pollutants may have effects that are passed on to subsequent generations without being genetically inherited in the Mendelian way. This can result from the transfer of epigenetic, cytoplasmic or somatic factors, nutrients, or extra-organismal environment from parents to offspring. Consequently, population adaptation may be determined by both epigenetic factors and selective forces. The ability of genomic approaches to disentangle the two categories of determinants has already been demonstrated and is expected to increase exponentially in the near future, thanks to current technological advances (e.g., next-generation sequencing). Also, quantitative genetics may provide useful methods to decompose phenotypic variation into parentally and genetically transmitted components.
Human activities contribute to an unprecedented rate of environmental change with which organisms have to deal. This is likely to trigger rapid micro-evolutionary and long-term effect processes. Therefore, it becomes urgent to be able to develop tools and methods to measure and predict such changes as well as to understand their consequences for ecosystems, including species distribution and long-term persistence.
During and following the session the audience expressed considerable interest in these topics, and a discussion was initiated on the potential usefulness of developing a SETAC Advisory Group on evolutionary, and multi- and trans-generational effects of chemicals in order to bridge the gap between science and implementation (proposal by Karel De Schamphelaere, University of Ghent, Belgium; together with the chairs). This initiative is currently under development.
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