Cryptic elevational zonation in trapdoor spiders (Araneae, Antrodiaetidae, Aliatypus janus complex) from the California southern Sierra Nevada
Cryptic elevational zonation in trapdoor spiders (Araneae, Antrodiaetidae, Aliatypus janus complex) from the California southern Sierra Nevada
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加利福尼亚州内华达山脉南部活板门蜘蛛（Araneae、Antrodiaetidae、Aliatypus janus 复合体）的隐秘海拔分区
DOI：
10.1016/j.ympev.2017.09.003
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发表时间：
2018
影响因子：
4.1
通讯作者：
Hedin, Marshal
中科院分区：
文献类型：
--
作者：
Starrett, James;Hayashi, Cheryl Y.;Derkarabetian, Shahan;Hedin, Marshal
生态位保守性与生态位差异在促进山地物种形成中的相对作用仍然是生物地理学中的一个重要课题。在这里，我们的目的是测试活门蜘蛛物种复合体中的谱系多样性是否与河流屏障或与海拔分层相关的生态梯度相对应。我们收集了多个基因座的遗传数据，生成了一个树种论坛。Janus和它的近亲。进行了基于合并的假设检验，以确定黄曲霉体内的基因断裂是否符合河流屏障。建立了当前和末次冰盛期(LGM)条件下的生态位模型(ENM)，并对生态位保守性和发散性进行了假设检验。合并分析显示，金线虫内的遗传谱系存在很大的差异，很可能对应于神秘的物种。两个主要血统在内华达山脉南部西坡的海拔梯度上相遇。当前和末次大冰川条件下的新生态系统表明，这些群体占据的生态位基本上是不重叠的。ENM假设检验拒绝了两组之间的生态位认同，并支持在两组相遇的地方出现急剧的生态梯度。然而，生态位相似性检验表明，这两个群体可能生活在不同的背景生态位中。内华达山脉为同时测试生态位多样性和保守性及其在不同分类群物种形成中的作用提供了一个天然实验室。Aliatypus janus代表一个物种复合体，具有神秘的谱系，可能是由于沿生态梯度的毗邻物种形成而发生分歧，或者是由于异地物种形成后生态位差异的演变而保持的。
The relative roles of ecological niche conservatism versus niche divergence in promoting montane speciation remains an important topic in biogeography. Here, our aim was to test whether lineage diversification in a species complex of trapdoor spiders corresponds with riverine barriers or with an ecological gradient associated with elevational tiering.Aliatypus januswas sampled from throughout its range, with emphasis on populations in the southern Sierra Nevada Mountains of California. We collected multi-locus genetic data to generate a species tree forA. janusand its close relatives. Coalescent based hypothesis tests were conducted to determine if genetic breaks withinA.janusconform to riverine barriers. Ecological niche models (ENM) under current and Last Glacial Maximum (LGM) conditions were generated and hypothesis tests of niche conservatism and divergence were performed. Coalescent analyses reveal deeply divergent genetic lineages withinA.janus, likely corresponding to cryptic species. Two primary lineages meet along an elevational gradient on the western slopes of the southern Sierra Nevada Mountains. ENMs under both current and LGM conditions indicate that these groups occupy largely non-overlapping niches. ENM hypothesis testing rejected niche identity between the two groups, and supported a sharp ecological gradient occurring where the groups meet. However, the niche similarity test indicated that the two groups may not inhabit different background niches. The Sierra Nevada Mountains provide a natural laboratory for simultaneously testing ecological niche divergence and conservatism and their role in speciation across a diverse range of taxa.Aliatypus janusrepresents a species complex with cryptic lineages that may have diverged due to parapatric speciation along an ecological gradient, or been maintained by the evolution of ecological niche differences following allopatric speciation.