Gene flow patterns and parentage in a burying beetle: using molecular genetics to study cryptic hehaviors

Nicrophorus investigator is a widespread carrion beetle species that has been the focus of ecological studies at Rocky Mountain Biological Laboratory for over 15 years. Two recent studies involve projected distribution shifts of Nicrophorus species in response to warming trends (Buffington 2009), and behavioral plasticity in reproductive decisions at different elevations (Pontius 2008). These studies; however, would benefit from information on N. investigator dispersal capabilities, population spatial extents, and the direct fitness consequences of alternative parental care decisions. Molecular genetic techniques can be used to study cryptic dispersal and reproductive behaviors, including those exhibited by this insect. DNA markers have been developed specifically for N. investigator, and are used to answer questions of (1) dispersal ability and habitat - gene flow interactions across landscapes, and (2) how different mating systems and parental care behaviors translate into fitness benefits. Initial results indicate topography is an important factor limiting dispersal, and gene flow is greater within river drainages than among them despite relatively short distances separating sample sites. Additionally, a high incidence of polypaternity has been observed in late season larval broods. Laboratory breeding experiments have been conducted to address the relationship between male parental care behaviors and paternity of current versus future broods. Evaluating gene flow patterns can help researchers understand cryptic habitat use, current and projected species distributions, and the potential for local adaptation. Understanding cryptic reproductive behaviors, such as temporal variation in male parental care, can provide insights into the evolution and stability of different mating systems.