Genetics of adaptation

Abstract

The rediscovery of Mendel's work showing that the heredity of phenotypes is controlled by discrete genes was followed by the reconciliation of Mendelian genetics with evolution by natural selection in the middle of the last century with the Modern Synthesis. In the past two decades, dramatic advances in genomic methods have facilitated the identification of the loci, genes, and even individual mutations that underlie phenotypic variants that are the putative targets of natural selection. Moreover, these methods have also changed how we can study adaptation by flipping the problem around, allowing us to first examine what loci show evidence of having been under selection, and then connecting these genetic variants to phenotypic variation. As a result, we now have an expanding list of actual genetic changes that underlie potentially adaptive phenotypic variation. Here, we synthesize how considering the effects of these adaptive loci in the context of cellular environments, genomes, organisms, and populations has provided new insights to the genetic architecture of adaptation.

Keywords: adaptation; evolution; evolutionary biochemistry; genetics; population genetics.

Fig. 1.

Examples of systems used to study the genetics of adaptation. (A) Pocket mice (Chaetodipus intermedius); (B) peppered moths (Biston betularia); (C) threespine sticklebacks (Gasterosteus aculeatus), with red marking bony structures; (D) monkeyflowers (Mimulus lewisii and Mimulus cardinalis; note: these species are now in the genus Erythranthe). See text for references. Drawings by K.B.