Deborah Charlesworth, winner of the society for the study of evolution's inaugural lifetime achievement award: Evolutionary biology for the genomics era

Deborah Charlesworth is a pioneer in the study of evolutionary genetics and plant reproductive evolution, and it would be difficult to overstate the extent to which she has influenced the more general field of evolutionary biology over the last four decades. Her research has led to fundamental advances in our understanding of a remarkably broad range of questions, including the evolution of sex chromosomes, the evolution of plant reproductive systems, the effects of deleterious mutations on genetic variation, and the evolutionary importance of inbreeding depression (as highlighted in perspectives by Mable and Hill 2008; Wright 2012). Equally comfortable with developing theoretical models and conducting empirical research to test these models (with one motivating the other), her work has been highly influential in bringing a theoretical underpinning to the empirical study of plant evolution, inspiring generations of researchers to test key evolutionary theory. It is truly remarkable the extent to which research papers, conference talks, and seminars over the past several decades have been motivated by models and empirical tests developed and proposed by Deborah and her research group. Rather than these contributions slowing down following her "retirement" in 2008, the relevance of Deborah’s early and current work on the research landscape has, if anything, accelerated in the recent years. With the rapid growth of genomics, some might have expected the massive quantities of new molecular data to render classic evolutionary models irrelevant. But, as I focus on here with the example of sex chromosome evolution, Deborah has proven quite the opposite; an evolutionary genetics perspective is key for understanding the burgeoning amounts of genomic data, and genomics is opening up exciting new questions and opportunities to address and parameterize evolutionary models. The striking variation in genome structure and organization across biological systems presents a new window into old evolutionary puzzles, and a new axis of variation with which to frame comparative evolutionary questions. One prime example of this concerns recent progress on our understanding of the evolution of separate sexes from hermaphroditism and the evolution of sex chromosomes. From early in her research career until the present, Deborah has been fascinated by evolutionary scenarios favoring the evolution of recombination. Although recombination is thought to be beneficial by enabling the spread of beneficial mutations and removal of harmful mutations independently of selection at linked sites, it can also break up favorable combinations of alleles, and under some conditions this can favor the evolution of suppressed recombination. This in turn can drive the formation of "supergenes" comprising linked regions with multiple genes (or multiple mutations in a single gene) that determine the combined inheritance of complex adaptations (Charlesworth 2016). A series of influential models developed early in Deborah’s research career, in collaboration with Brian Charlesworth, identified the conditions under which supergene formation can occur to explain the spread of Batesian mimicry in butterflies (Charlesworth and Charlesworth 1975), the origins of heteromorphic self-incompatibility systems in plants (Charlesworth and Charlesworth 1979) and the transition from hermaphroditism to separate sexes and subsequent formation of sex chromosomes (Charlesworth and Charlesworth 1978). The models highlighted that the genetic details, such as the extent to which the genes contributing to the trait are genetically linked a priori, and the nature of pleiotropic fitness effects of mutations, can be key