Kin Recognition in Polyphenic Species

普芬尼格，大卫9512110 摘要 这项研究将使用两栖动物作为模型系统，以了解某些动物如何以及为什么识别它们的亲属。 亚利桑那虎蝾螈的幼虫是不寻常的，因为它们在自然界中有两种不同的类型：一种是“典型的”变体，另一种是“食人的”变体。 只有当幼虫聚集在高密度时，才会产生食人的变体，这种变体主要以其他虎蝾螈为食。 在实验室和野外，当与亲缘关系不同的较小幼虫一起生活时，食人族会优先食用亲缘关系较低的个体。 这种区别在来自特别可能产生食人变种的家庭的幼虫中最为明显。 这项研究将测试两个非排他性的进化假说，为什么食人族承认他们的亲戚。 首先，通过不吃一个亲戚，由于共同的血统，食人者与他们共享一些基因，食人者可以间接增加他们自己的遗传代表性或“包容性”适应性。 或者，食人族可能会避免吃亲戚，以减少他们死于疾病的机会。 在自然界中，一种致命的细菌可以感染这些动物，而同类相食是获得这种疾病的一种特别有效的方式。此外，这种传染性病原体可能在近亲中高度传播，这可能是因为亲属具有相似的免疫系统。 这项研究将使用现场观察和现场和实验室实验来测试每个假设的具体预测。虎蝾螈是一个理想的模型系统分离的直接和间接的包容性健身的亲属歧视的后果。 因此，这项研究有望帮助解决为什么某些动物识别亲属，这对当前关于利他主义进化的理论很重要。 这项研究还将增加对亲属关系在疾病传播中的作用的理解。

Pfennig, David 9512110 Abstract This research will use amphibians as a model system to understand how and why certain animals identify their relatives. Larval Arizona tiger salamanders are unusual in that they occur in nature as two distinct types: a 'typical' morph and a 'cannibal' morph. The cannibal morph is produced only when larvae are crowded at high densities, and this morph feeds primarily on other tiger salamanders. When housed with smaller larvae that differ in relatedness, cannibals preferentially consume less related individuals, both in the laboratory and in the field. This discrimination is most pronounced among larvae from families that are especially likely to produce cannibal morphs. This research will test two non-exclusive evolutionary hypotheses on why cannibals recognize their relatives. First, by not eating a relative, with whom the cannibal shares some genes due to common descent, cannibals can indirectly increase their own genetic representation or "inclusive" fitness in the population. Alternatively, cannibals may avoid eating kin to lessen their chances of dying from disease. In nature, a deadly bacterium can infect these animals, and cannibalism is an especially efficient way of acquiring the disease. Moreover, this infectious agent may be highly transmissible among close relatives, perhaps because kin have similar immune systems. This research will use field observations and field and laboratory experiments to test specific predictions made by each hypothesis. Tiger salamanders are an ideal model system for separating the direct and indirect inclusive fitness consequences of kin discrimination. This study thus promises to help resolve why certain animals recognize kin, which is important to current theories concerning the evolution of altruism. The research will also increase understanding of the role of kinship in disease transmission.