Michael Lynch, Indiana University, "Mutation and Evolution"
May 6 2010, 11:00 am
Distinguished Lecture Series Guest Speaker:
Distinguished Professor, Department of Biology
Indiana University, Bloomington
Date & Time:Thursday May 06, 2010, 11:00AM
Understanding the mechanisms of evolution and the degree to which generalities exist among phylogenetic lineages requires information on the rate at which mutations arise and their effects at the molecular and phenotypic levels. Although procuring such data has been technically challenging, high-throughput genomic sequencing is rapidly expanding our knowledge in this area. With information on spontaneous mutations now available in a variety of organisms, general patterns have emerged for the scaling of the mutation rate with genome size, and support is presented for the hypothesis that natural selection pushes mutation rates down to a lower limit set by the power of random genetic drift rather than by intrinsic limitations on repair mechanisms. Not only do larger, multicellular organisms have higher mutation rates / nucleotide site / generation than unicellular species, but gene structure in the former evolves in such a way as to become a larger mutational target. This sort of mutation-rate scaling with effective population sizes has implications for the rapidity with which various pathways can be exploited in adaptive evolution in different lineages, as well as consequences for the accumulation of deleterious mutations, a special concern in our own species.