Monster Seminar JAM - Unnatural selection: human-induced evolution in exploitation of wild animals
Dr. Jeff Hard, Northwest Fisheries Science Center, NOAA Fisheries
Human harvest of wild animal populations imposes selection that can reduce the frequencies of those phenotypes among breeders. Hunting, fishing, and other forms of human exploitation contrast with agriculture and aquaculture, where the most desirable individuals are selected for breeding to increase the frequency of particular phenotypes. There has been surprisingly little consideration of human-induced selection in the wild until recently. Although Darwin himself recognized the potential for exploitation to cause evolution, he did not apply his evaluation of methodological, unconscious, and natural selection to wild animals and plants. We consider the potential effects of human exploitation on the genetics and sustainability of wild populations. We consider how harvesting can affect the mating system and thereby modify sexual selection in a way that might affect viability. Determining whether phenotypic changes in harvested populations are due to evolution, rather than phenotypic plasticity or environmental variation, has been challenging. However, it is likely that some undesirable changes observed in exploited populations over time are due to selection against particular phenotypes that arise from natural or sexual selectiona process we call unnatural selection. Evolution induced by human harvest can increase the risk of population collapse, and might greatly increase the time it will take over-harvested populations to recover once harvest is curtailed because harvesting often creates strong selection differentials, whereas curtailing harvest will generally result in less intense selection in the opposing direction.
Date and Time:
October 8, 2009,
11:00 am - 12:00 pm