Sibling competition does not exacerbate inbreeding depression in the burying beetleNicrophorus vespilloides

Pilakouta, N. , Sieber, D.J. and Smiseth, P.T. (2016) Sibling competition does not exacerbate inbreeding depression in the burying beetleNicrophorus vespilloides. Journal of Evolutionary Biology, 29(4), pp. 704-710. (doi: 10.1111/jeb.12816) (PMID:26709848)

Abstract

Inbreeding results from matings between relatives and can cause a reduction in offspring fitness, known as inbreeding depression. Previous work has shown that a wide range of environmental stresses, such as extreme temperatures, starvation and parasitism, can exacerbate inbreeding depression. It has recently been argued that stresses due to intraspecific competition should have a stronger effect on the severity of inbreeding depression than stresses due to harsh physical conditions. Here, we tested whether an increase in the intensity of sibling competition can exacerbate inbreeding depression in the burying beetle Nicrophorus vespilloides. We used a 2 × 3 factorial design with offspring inbreeding status (outbred or inbred) and brood size (5, 20, or 40 larvae) as the two factors. We found a main effect of inbreeding status, as inbred larvae had lower survival than outbred larvae, and a main effect of brood size, as larvae in large broods had lower survival and mass than larvae in medium-sized broods. However, there was no effect of the interaction between inbreeding status and brood size, suggesting that sibling competition did not influence the severity of inbreeding depression. Since we focused on sibling competition within homogeneous broods of either inbred or outbred larvae, we cannot rule out possible effects of sibling competition on inbreeding depression in mixed paternity broods comprising of both inbred and outbred offspring. More information on whether and when sibling competition might influence inbreeding depression can help advance our understanding of the causes underlying variation in the severity of inbreeding depression.

• Item Type: Articles
• Additional Information: The study was funded by the Institute of Evolutionary Biology and the School of Biological Sciences, University of Edinburgh.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Pilakouta, Dr Natalie
• Authors: Pilakouta, N., Sieber, D.J., and Smiseth, P.T.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Journal of Evolutionary Biology
• Publisher: Wiley
• ISSN: 1010-061X
• ISSN (Online): 1420-9101
• Published Online: 28 December 2015