Extended haplodiploidy hypothesis

Evolution of altruistic behaviour was a hurdle for the logic of Darwinian evolution. Soon after Hamilton formalised the concept of inclusive fitness, which explains how altruism can evolve, he suggested that the high sororal relatedness brought by haplodiploidy could be why Hymenopterans have a high prevalence in eusocial species, and why helpers in Hymenoptera are always female. Later it was noted that in order to capitalize on the high sororal relatedness, helpers would need to direct help towards sisters, and this would bias the population sex ratio. Under a 1:3 males:females sex ratio, the inclusive fitness valuation a female places on her sister, brother and an own offspring are equal – apparently removing the benefit of helping over independent reproduction. Based on this argumentation, haplodiploidy hypothesis has been considered a red herring. However, here we show that when population sex ratio, cost of altruism, and population growth rate are considered together, haplodiploidy...利他行为的演化曾是达尔文进化论逻辑中的一大难题。在汉密尔顿正式提出用以解释利他行为演化机制的广义适合度（inclusive fitness）概念后不久，他便提出：单倍二倍性（haplodiploidy）所带来的高姐妹亲缘度，或许正是膜翅目昆虫（Hymenopterans）在真社会性物种（eusocial species）中占比颇高，且其社会性帮手均为雌性的原因。后续研究指出，若要利用这种高姐妹亲缘度，社会性帮手需将帮助行为定向给予姐妹，而这会导致种群性比偏离平衡。在雄性与雌性比例为1:3的种群中，雌性对其姐妹、兄弟以及自身后代的广义适合度估值完全相等——这似乎意味着帮助行为相较于独立繁殖并无额外收益。基于这一论证，单倍二倍性假说一度被视作伪命题（red herring）。然而本文研究表明，当综合考量种群性比、利他行为成本与种群增长率时，单倍二倍性……