Dey Cody J, O'Connor Constance M, Wilkinson Holly, Shultz Susanne, Balshine Sigal, Fitzpatrick John L
Department of Psychology, Neuroscience, and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
Nat Ecol Evol. 2017 Apr 18;1(5):137. doi: 10.1038/s41559-017-0137.
The selective forces that drive the evolution of cooperation have been intensely debated. Evolutionary transitions to cooperative breeding, a complex form of cooperation, have been hypothesized to be linked to low degrees of promiscuity, which increases intragroup relatedness and the indirect (that is, kin selected) benefits of helping. However, ecological factors also promote cooperative breeding, and may be more important than relatedness in some contexts. Identifying the key evolutionary drivers of cooperative breeding therefore requires an integrated assessment of these hypotheses. Here we show, using a phylogenetic framework that explicitly evaluates mating behaviours and ecological factors, that evolutionary transitions to cooperative breeding in cichlid fishes were not associated with social monogamy. Instead, group living, biparental care and diet type directly favoured the evolution of cooperative breeding. Our results suggest that cichlid fishes exhibit an alternative path to the evolution of complex societies compared to other previously studied vertebrates, and these transitions are driven primarily by direct fitness benefits.
推动合作进化的选择力一直是激烈辩论的焦点。向合作繁殖（一种复杂的合作形式）的进化转变被假设与低乱交程度有关，低乱交程度会增加群体内的亲缘关系以及帮助行为的间接（即亲缘选择）益处。然而，生态因素也促进了合作繁殖，并且在某些情况下可能比亲缘关系更为重要。因此，确定合作繁殖的关键进化驱动因素需要对这些假设进行综合评估。在这里，我们使用一个明确评估交配行为和生态因素的系统发育框架表明，丽鱼科鱼类向合作繁殖的进化转变与社会一夫一妻制无关。相反群体生活、双亲照料和饮食类型直接促进了合作繁殖的进化。我们的结果表明，与其他先前研究过的脊椎动物相比，丽鱼科鱼类展现出了一条通往复杂社会进化的不同路径，并且这些转变主要由直接的适应性益处驱动。
