Behavioral genetics and genomics: Mendel’s peas, mice,and bees

The question of the heritability of behavior has been of long fascination to scientists and the broader public. It is now widely accepted that most behavioral variation has a genetic component, although the degree of genetic in fl u- ence differs widely across behaviors. Starting with Men- del ’ s remarkable discovery of “ inheritance factors, ” it has become increasingly clear that speci fi c genetic variants that in fl uence behavior can be identi fi ed. This goal is not without its challenges: Unlike pea morphology, most natu- ral behavioral variation has a complex genetic architec- ture. However, we can now apply powerful genome-wide approaches to connect variation in DNA to variation in behavior as well as analyses of behaviorally related varia- tion in brain gene expression, which together have pro- vided insights into both the genetic mechanisms underlying behavior and the dynamic relationship between genes and behavior, respectively, in a wide range of species and for a diversity of behaviors. Here, we focus on two systems to illustrate both of these approaches: the genetic basis of bur- rowing in deer mice and transcriptomic analyses of division of labor in honey bees. Finally, we discuss the troubled rela- tionship between the fi eld of behavioral genetics and eugenics, which reminds us that we must be cautious about how we discuss and contextualize the connections between genes and behavior, especially in humans.