Hopwood P E, Mazué G P F, Carter M J, Head M L, Moore A J, Royle N J
Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK
Department of Collective Behaviour, Max Planck Institute for Ornithology, University of Konstanz, Konstanz, Germany Department of Biology, University of Konstanz, Konstanz, Germany.
Biol Lett. 2016 Mar;12(3):20151064. doi: 10.1098/rsbl.2015.1064.
Sexual conflict occurs when selection to maximize fitness in one sex does so at the expense of the other sex. In the burying beetle Nicrophorus vespilloides, repeated mating provides assurance of paternity at a direct cost to female reproductive productivity. To reduce this cost, females could choose males with low repeated mating rates or smaller, servile males. We tested this by offering females a dichotomous choice between males from lines selected for high or low mating rate. Each female was then allocated her preferred or non-preferred male to breed. Females showed no preference for males based on whether they came from lines selected for high or low mating rates. Pairs containing males from high mating rate lines copulated more often than those with low line males but there was a negative relationship between female size and number of times she mated with a non-preferred male. When females bred with their preferred male the number of offspring reared increased with female size but there was no such increase when breeding with non-preferred males. Females thus benefited from being choosy, but this was not directly attributable to avoidance of costly male repeated mating.
当在一个性别中最大化适合度的选择是以牺牲另一个性别的适合度为代价时,就会发生性冲突。在埋葬虫尼可罗蜚蠊中,多次交配能确保父权,但这会直接降低雌性的生殖生产力。为了降低这种代价,雌性可以选择多次交配率低的雄性,或者体型较小、顺从的雄性。我们通过让雌性在高交配率品系或低交配率品系的雄性之间进行二分选择来测试这一点。然后给每只雌性分配其偏好或不偏好的雄性进行繁殖。雌性对来自高交配率品系或低交配率品系的雄性没有偏好。与低交配率品系雄性配对的个体相比,与高交配率品系雄性配对的个体交配更频繁,但雌性体型与其与不偏好雄性交配的次数之间存在负相关。当雌性与偏好的雄性繁殖时,养育的后代数量随雌性体型增加,但与不偏好的雄性繁殖时则没有这种增加。因此,雌性因挑剔而受益,但这并非直接归因于避免雄性多次交配带来的代价。