Kin but less than kind: within-group male relatedness does not increase female fitness in seed beetles

Elena C. Berg, Martin I. Lind, Shannon Monahan, Sophie Bricout, Alexei A. Maklakov

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)
25 Downloads (Pure)


Theory maintains within-group male relatedness can mediate sexual conflict by reducing male-male competition and collateral harm to females. We tested whether male relatedness can lessen female harm in the seed beetle Callosobruchus maculatus. Male relatedness did not influence female lifetime reproductive success or individual fitness across two different ecologically relevant scenarios of mating competition. However, male relatedness marginally improved female survival. Because male relatedness improved female survival in late life when C. maculatus females are no longer producing offspring, our results do not provide support for the role of within-group male relatedness in mediating sexual conflict. The fact that male relatedness improves the post-reproductive part of the female life cycle strongly suggests that the effect is non-adaptive. We discuss adaptive and non-adaptive mechanisms that could result in reduced female harm in this and previous studies, and suggest that cognitive error is a likely explanation.

Original languageEnglish
JournalProceedings of the Royal Society B: Biological Sciences
Issue number1910
Publication statusPublished - 11 Sep 2019


  • Callosobruchus maculatus
  • kin selection
  • mate harm
  • sexual conflict

Cite this