When earwig mothers do not care to share: parent-offspring competition and the evolution of family life

1. Kin competition often reduces – and sometimes entirely negates – the benefits of cooperation among relatives, and hence is often regarded as central process in social evolution. Surprisingly, however, our understanding of the role of kin competition in the evolution of family life remains fragmentary, despite the close scrutiny it received in studies on sibling rivarly. This is because much less attention has been given to local competition between parents and their offspring, and its potential impact on the early evolution of parental care and family life.
2. Here, we examined mother-offspring competition over food access in the European earwig Forficula auricularia, an insect with facultative family life. Specifically, we (i) raised earwig offspring under food limitation either together with or without their mother, and then (ii) tested whether and how the – potentially competitive – weight gains of mothers and offspring during family life affected the offsprings’ survival rate an...

1. 亲缘竞争往往会削弱——有时甚至完全抵消——亲属间合作的收益，因此常被视为社会进化的核心过程。然而令人意外的是，尽管学界已针对同胞竞争开展了大量细致研究，但我们对亲缘竞争在家族生活进化中所扮演角色的认知仍较为零散。这是因为学界对亲本与其后代间的局部竞争，及其对亲本抚育与家族生活早期进化的潜在影响关注甚少。
2. 本研究以兼具兼性家族生活习性的昆虫欧洲蠼螋（Forficula auricularia）为对象，探究了母子间针对食物获取的竞争。具体而言，我们（i）将蠼螋后代置于食物限制条件下，分别与其母亲共同饲养或单独饲养；随后（ii）检验了家族生活期间母子双方潜在具有竞争性的体重增长，是否以及如何影响后代的存活率及……