DSSS - Understanding polygenic adaptation with experimental evolution

Most adaptive traits have a complex genetic architecture with many contributing loci. In contrast to the phenotypic response, the genomic signatures of polygenic adaptation are notoriously difficult to detect: since many alleles contribute to the adaptive phenotype, only small allele frequency changes are needed to move the phenotype to the new optimum. Hence, even with very large sample sizes, such small allele frequency shifts cannot be detected reliably. Experimental evolution from standing genetic variation in sexual organisms, such as Drosophila, provide the unique opportunity to study the genetic architecture of polygenic adaptation. I will discuss how experimental evolution can uncover genetic redundancy, provide insights about pleiotropy and highlight the role of linkage disequilibrium.