Evolutionary importance of parental care performance, food resources, and direct and indirect genetic effects in a burying beetle

In many animal taxa, parental care is a critical environmental influence on offspring growth and development (Clutton-Brock, 1991). Parents with high energetic investment in parental care influence offspring mass positively (Moreno et al., 1997; Burness et al., 2001). Provisioning offspring with an energy-rich and/or a high quality diet improves growth rate of offspring and reduces duration of developmental phases critical for offspring survival (Watanuki, 1992; Johnston, 1993; Meyer et al., 1994; Rogowitz & McClure, 1995; Rogowitz, 1996; Oksanen et al., 1999; Hunt & Simmons, 2000; Kunz & Ekman, 2000; Rauter & Moore, 2002). Variation in parental care can therefore result in variation in offspring traits. Variation in parental care, often described in terms of variation in the effects of parental care or as ‘parental performance’, can be an important evolutionary influence (Kirkpatrick & Lande, 1989, 1992; Lande & Kirkpatrick, 1990; Cheverud & Moore, 1994; Mousseau & Fox, 1998; Wolf et al., 1998). A consideration of the evolutionary effects of parental performance, however, requires an explicit consideration of both environmental and genetic influences over multiple generations (Cheverud & Moore, 1994). Like any parental trait, parental performance may be influenced by the environment to which the parent is exposed (Fig. 1: path 1) and the genes expressed in the parent (Fig. 1: path 2). Parental genes