PDF(Pubmed)
Abstract：
Inbreeding depression, the loss of offspring fitness due to consanguineous mating, is generally detrimental for individual performance and population viability. We investigated inbreeding effects in a declining population of Antarctic fur seals (Arctocephalus gazella) at Bird Island, South Georgia. Here, localised warming has reduced the availability of the seal\'s staple diet, Antarctic krill, leading to a temporal increase in the strength of selection against inbred offspring, which are increasingly failing to recruit into the adult breeding population. However, it remains unclear whether selection operates before or after nutritional independence at weaning. We therefore used microsatellite data from 885 pups and their mothers, and SNP array data from 98 mother-offspring pairs, to quantify the effects of individual and maternal inbreeding on three important neonatal fitness traits: birth mass, survival and growth. We did not find any clear or consistent effects of offspring or maternal inbreeding on any of these traits. This suggests that selection filters inbred individuals out of the population as juveniles during the time window between weaning and recruitment. Our study brings into focus a poorly understood life-history stage and emphasises the importance of understanding the ecology and threats facing juvenile pinnipeds.
摘要：
近亲繁殖抑郁症,由于近亲交配导致后代健康的丧失，通常对个体表现和群体生存能力有害。我们调查了鸟岛南极海豹（Arctocalusgazella）种群减少的近亲繁殖效应，南乔治亚。这里,局部变暖降低了海豹主食的可用性，南极磷虾,导致对近交后代的选择强度暂时增加，越来越多的人无法招募到成年繁殖人群中。然而,尚不清楚选择是在断奶时营养独立之前还是之后进行。因此，我们使用了885只幼崽及其母亲的微卫星数据，和来自98个母子对的SNP阵列数据，量化个体和母体近亲繁殖对三个重要新生儿健康特征的影响：出生质量，生存和成长。我们没有发现后代或母本近亲繁殖对这些性状的任何明显或一致的影响。这表明，在断奶和招募之间的时间窗口中，选择将近交系个体从种群中过滤为少年。我们的研究将重点放在了一个鲜为人知的生活史阶段，并强调了了解幼年大足动物面临的生态和威胁的重要性。
