Hain Timothy J A, Neff Bryan D
Department of Biology, University of Western Ontario, London, Ontario, Canada N6A 5B7.
Mol Ecol. 2007 Sep;16(18):3938-46. doi: 10.1111/j.1365-294X.2007.03443.x.
Help directed toward kin (nepotism) is an important example of social behaviour. Such helping behaviour requires a mechanism to distinguish kin from nonkin. The prevailing kin recognition hypothesis is that when familiarity is a reliable cue of relatedness, other mechanisms of recognition will not evolve. However, when familiarity is an unreliable cue of relatedness, kin recognition by phenotype matching is instead predicted to evolve. Here we use genetic markers to show that guppies (Poecilia reticulata) from a population in a tributary of the Paria River in Trinidad are characterized by a high degree of multiple mating with 95% of broods having more than one sire and some dams having offspring sired by six males. These levels of multiple mating are the highest reported among live-bearing fishes. The mean relatedness of brood-mates was 0.36 (as compared to 0.5 for full-siblings). Therefore, familiarity does not seem to be a reliable mechanism to assess full-sibling relatedness. Using two-choice behavioural trials, we found that juveniles from this population use both phenotype matching and familiarity to distinguish kin from nonkin. However, we did not find strong evidence that the guppies use these mechanisms to form shoals of related individuals as adults, which is similar to results from other guppy populations in Trinidad. The use of both familiarity and phenotype matching is discussed in the context of the Paria River guppy population's mating system and ecology. Overall, these data provide support for the kin recognition hypothesis and increase our understanding of the evolution of kin recognition systems.
针对亲属的帮助行为（裙带关系）是社会行为的一个重要例子。这种帮助行为需要一种机制来区分亲属和非亲属。目前流行的亲属识别假说认为，当熟悉程度是亲属关系的可靠线索时，其他识别机制就不会进化。然而，当熟悉程度不是亲属关系的可靠线索时，通过表型匹配进行亲属识别反而会进化。在这里，我们使用遗传标记表明，特立尼达帕里亚河一条支流中的孔雀鱼种群具有高度的多配偶特征，95%的鱼窝有多个父亲，一些雌鱼的后代由六个雄性所生。这些多配偶程度是胎生鱼类中报道的最高水平。同窝幼鱼的平均亲缘系数为0.36（而全同胞的亲缘系数为0.5）。因此，熟悉程度似乎不是评估全同胞亲属关系的可靠机制。通过双选行为试验，我们发现这个种群的幼鱼同时使用表型匹配和熟悉程度来区分亲属和非亲属。然而，我们没有找到有力证据表明孔雀鱼成年后会利用这些机制形成亲属群体，这与特立尼达其他孔雀鱼种群的结果相似。我们在帕里亚河孔雀鱼种群的交配系统和生态学背景下讨论了熟悉程度和表型匹配的使用情况。总体而言，这些数据为亲属识别假说提供了支持，并增进了我们对亲属识别系统进化的理解。
