Data from: Kin recognition in a clonal fish, Poecilia formosa

Relatedness strongly influences social behaviors in a wide variety of species. For most species, the highest typical degree of relatedness is between full siblings with 50% shared genes. However, this is poorly understood in species with unusually high relatedness between individuals: clonal organisms. Although there has been some investigation into clonal invertebrates and yeast, nothing is known about kin selection in clonal vertebrates. We show that a clonal fish, the Amazon molly (Poecilia formosa), can distinguish between different clonal lineages, associating with genetically identical, sister clonals, and use multiple sensory modalities. Also, they scale their aggressive behaviors according to the relatedness to other females: they are more aggressive to non-related clones. Our results demonstrate that even in species with very small genetic differences between individuals, kin recognition can be adaptive. Their discriminatory abilities and regulation of costly behaviors provides a powerful example of natural selection in species with limited genetic diversity.

亲缘关联度对多种物种的社会行为具有显著影响。对于多数物种而言，典型的最高亲缘关联度存在于共享50%基因的全同胞个体之间。然而，对于个体间亲缘关联度异乎寻常地高的物种——克隆生物（clonal organisms）——这一现象的相关机制仍鲜为人知。尽管已有部分针对克隆无脊椎动物与酵母的研究，但针对克隆脊椎动物的亲缘选择（kin selection）机制仍一无所知。本研究表明，一种克隆繁殖的鱼类亚马逊鳉（Amazon molly, Poecilia formosa）能够区分不同的克隆谱系，可与遗传完全一致的同胞克隆个体建立社会关联，并依赖多种感官模态完成识别。此外，它们会根据与其他雌性个体的亲缘关联度调整攻击行为的强度：对非亲缘克隆个体的攻击性更强。本研究结果证实，即便在个体间遗传差异极小的物种中，亲缘识别（kin recognition）依然具有适应性价值。它们的识别能力与代价性行为调控机制，为遗传多样性有限的物种中的自然选择（natural selection）提供了极具说服力的例证。