Adaptation, Genetic Drift, Pleiotropy, and History in the Evolution of Bee Foraging Behavior

The formal study of foraging behavior began in the mid 1960s, using an approach that later became known as optimal foraging theory (Emlen, 1966; MacArthur and Pianka, 1966). Practitioners would use modeling to identify an optimal strategy for an animal facing a given number of foraging options, and then compare this to the strategy actually chosen by the animal (Maynard Smith, 1978; Orzack and Sober, 2001; Stephens and Krebs, 1991). This approach was instrumental in predicting quantitatively which types of food an animal should choose to consume (Pyke et al., 1977; Stephens and Krebs, 1991; Waddington and Holden, 1979), when to abandon a patch of food (Cuthill et al., 1990; Kacelnik and Krebs, 1985), how variance in food supply might affect forager choice (Fülöp and Menzel, 2000; Real, 1981; Shafir et al., 1999), and what currencies animals use in making decisions about food quality (McNamara et al., 1993; Schmid‐ Hempel et al., 1985). The field thrived and expanded rapidly throughout the 1970s and 1980s, receiving further impetus from studies on the neurobiological mechanisms that underlie and constrain foraging during the 1990s (Chittka et al., 1999; Clayton, 1995; Clayton and Krebs, 1994; Greggers and Menzel, 1993), and from studies into the genetic basis of foraging behavior (Ben‐Shahar et al., 2002; Rueppell et al., 2004a).