Abstracts (first author)
Experimental thermal evolution in D. melanogaster reveals temperature dependent population genomic signal of adaptation
How adaptation effects segregating variation at the population genomic level in sexually reproducing diploids remains a poorly understood yet fundamental biological question. However, recent advances in sequencing technology in combination with experimental evolution have promised to reveal the temporal patterns of genomic adaptation down to individual SNP resolution. Here I discuss results from 15 generations of experimental evolution in replicated populations of D. melanogaster maintained in two separate thermal environments, which mimic either heat and cold stress. When taking the top candidate SNPs from each base-evolved population comparison, we find an enrichment of hot candidate SNPs in genes associated with heat tolerance, and likewise for cold candidate SNPs in cold tolerance genes, but not vice versa. Furthermore, we find that the rising allele (i.e. that most likely to be under selection) tends to start at either low or intermediate frequencies in the hot and cold treatments, respectively. Hence, it appears that thermal selection is involved in driving changes between the two treatments and is deferentially dependent on the starting allele frequency. The possible causes behind these intriguing patterns are discussed with respect to our emerging understanding of thermal adaption in D. melanogaster.