Benefits of polyandry in Molecular Ecology

Molecular Ecology just published a paper on dung beetles that Erin McCullough (the lead author), Leigh Simmons and I conducted here at the University of Western Australia. In a nutshell, we collected mated females of the dung beetle Onthophagus taurus from the field, allowed them to breed (make brood balls and lay eggs) in the lab, and then genotyped their offspring and used microsats (thanks to Erin's amazing molecular skills!) to estimate the (minimum) number of males each female mated with, and their relative fertilization success in each clutch. We found that females of the species are highly polyandrous (88% of them were, some having mated with at least 5 males in the field!!). We also found significant paternity skew (some males sired more offspring than others), suggestive of sexual selection in the field. Finally, the coolest thing was that paternity skew (the amount of sexual selection) was correlated with the number of offspring produced, suggesting a benefit of polyandry and a benefit of sexual selection! Dung beetles are just the coolest...