Am Nat. 2019 Apr;193(4):608-618. doi: 10.1086/702251. Epub 2019 Mar 1.
Understanding polymorphism is a central problem in evolution and ecology, and alternative reproductive tactics (ARTs) provide compelling examples for studying the origin and maintenance of behavioral and morphological variation. Much attention has been given to examples where "parasitic" individuals exploit the reproductive investment of "bourgeois" individuals, but some ARTs are instead maintained by environmental heterogeneity, with alternative tactics exhibiting differential fitness in discontinuous reproductive niches. We use genomic, behavioral, karyological, and field observational data to demonstrate one such example in plethodontid salamanders. These ARTs ("searching" and "guarding" males) are associated with different reproductive niches and, unlike most other examples in amphibians, demonstrate substantial morphological differences and inflexibility within a reproductive season. Evidence suggests the existence of these ARTs within three putative species in the two-lined salamander (Eurycea bislineata) species complex, with other members of this clade fixed for one of the two tactics. We highlight directions for future research in this system, including the relationship between these ARTs and parental care.
理解多态性是进化和生态学中的一个核心问题，而替代性生殖策略（ARTs）为研究行为和形态变异的起源和维持提供了引人注目的例子。人们已经关注了许多“寄生”个体利用“资产阶级”个体的生殖投资的例子，但有些 ART 则是通过环境异质性维持的，替代策略在不连续的生殖小生境中表现出不同的适合度。我们使用基因组、行为、染色体和实地观测数据来证明在 plethodontid 蝾螈中存在这样一个例子。这些 ART（“搜索”和“守护”雄性）与不同的生殖小生境相关，与两栖动物中的大多数其他例子不同，它们在一个生殖季节内表现出显著的形态差异和缺乏灵活性。有证据表明，在两线蝾螈（Eurycea bislineata）种复合体中的三个假定物种中存在这些 ART，而这个分支的其他成员则固定为两种策略之一。我们强调了在这个系统中进行未来研究的方向，包括这些 ART 与亲代照顾之间的关系。
