Persistence of a Geographically-Stable Hybrid Zone in Puerto Rican Dwarf Geckos
Persistence of a Geographically-Stable Hybrid Zone in Puerto Rican Dwarf Geckos
复制标题
波多黎各矮壁虎地理稳定混合区的持续存在
DOI：
10.1093/jhered/esz015
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发表时间：
2019
影响因子：
3.1
通讯作者：
Gamble, Tony
中科院分区：
文献类型：
--
作者：
Pinto, Brendan J;Titus-McQuillan, James;Daza, Juan D;Gamble, Tony
确定创造和维持生物多样性的机制是生态学和进化的核心问题。物种形成是创造生物多样性的过程。物种形成是由导致不同种群之间生殖隔离的不相容性介导的，这些不相容性可以在杂交区中观察到。壁虎蜥蜴是一个具有令人印象深刻的多样性的行为和形态特征的物种分支。然而，在壁虎身上，我们对物种形成过程的理解是微不足道的。为了解决这一差距，我们使用遗传序列数据（线粒体和核标记），重新访问一个假定的混合区Sphaerodactylus nicholsiandSphaerodactylus townsendiin波多黎各，最初描述于1984年。首先，我们解决了两个物种的有效性在文献中的差异。其次，我们采样了一个10公里宽的横断面整个假定的混合区，并测试明确的预测其动态渐变模型。第三，我们调查了潜在的原因，混合区使用物种分布建模和模拟，即，是否独特的气候变量在混合区可能会引起选择中间表型。我们发现强有力的支持，每个物种的物种水平的地位，没有证据的运动，或独特的气候变量附近的混合区。我们认为，这个狭窄的混合区是地理上稳定的，并保持了扩散和选择的组合。因此，这项工作已经确定了壁虎中现存的模型系统，可用于未来的研究，详细说明未充分研究的脊椎动物群体中生殖隔离的遗传机制。
Determining the mechanisms that create and maintain biodiversity is a central question in ecology and evolution. Speciation is the process that creates biodiversity. Speciation is mediated by incompatibilities that lead to reproductive isolation between divergent populations and these incompatibilities can be observed in hybrid zones. Gecko lizards are a speciose clade possessing an impressive diversity of behavioral and morphological traits. In geckos, however, our understanding of the speciation process is negligible. To address this gap, we used genetic sequence data (both mitochondrial and nuclear markers) to revisit a putative hybrid zone betweenSphaerodactylus nicholsiandSphaerodactylus townsendiin Puerto Rico, initially described in 1984. First, we addressed discrepancies in the literature on the validity of both species. Second, we sampled a 10-km-wide transect across the putative hybrid zone and tested explicit predictions about its dynamics using cline models. Third, we investigated potential causes for the hybrid zone using species distribution modeling and simulations; namely, whether unique climatic variables within the hybrid zone might elicit selection for intermediate phenotypes. We find strong support for the species-level status of each species and no evidence of movement, or unique climatic variables near the hybrid zone. We suggest that this narrow hybrid zone is geographically stable and is maintained by a combination of dispersal and selection. Thus, this work has identified an extant model system within geckos that that can be used for future investigations detailing genetic mechanisms of reproductive isolation in an understudied vertebrate group.