Convergent life-history shifts: toxic environments result in big babies in two clades of poeciliids
Convergent life-history shifts: toxic environments result in big babies in two clades of poeciliids
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生命史的趋同转变：有毒环境导致两个拟鱼科进化枝中的大婴儿
DOI：
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
I. Schlupp
中科院分区：
文献类型：
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作者：
R. Riesch;M. Plath;F. J. García de León;I. Schlupp
大多数关于动物生态物种形成的研究都研究了由生物因素如不同的食物来源或捕食制度引起的分歧。在这里，我们研究了一个系统，生态物种形成可以清楚地归因于非生物环境梯度的天然存在的有毒硫化氢（H2S）。在墨西哥南部，有两个属的活产鱼（Poeciliidae：Poecilia和Gambusia）在不同的H2S浓度的水道中茁壮成长。以前的研究表明，在一个物种（Poecilia mexicana）不同的本地适应人群之间的明显的遗传分化，指向早期的物种形成。在本研究中，我们研究了两个物种对的雌性生殖生活史特征：Gambusia sexradiata（来自非硫化物和硫化物栖息地）和Gambusia eurystoma（硫化物特有），以及P. mexicana（非硫化物和硫化物）和Poecilia sulphuraria（硫化物特有）。我们发现收敛发散的生活史特征的硫化物，最突出的是，极端嗜poeciliids表现出急剧增加的后代大小，加上减少生育力。此外，在每个属内，这种趋势随着硫化物浓度的增加而增加，并且在两个地方性硫适应物种中最为明显。我们讨论了大的后代大小在有毒环境中的适应意义，并提出不同的生活史进化可能会促进进一步的生态分歧，通过适应隔离。
The majority of studies on ecological speciation in animals have investigated the divergence caused by biotic factors like divergent food sources or predatory regimes. Here, we examined a system where ecological speciation can clearly be ascribed to abiotic environmental gradients of naturally occurring toxic hydrogen sulfide (H2S). In southern Mexico, two genera of livebearing fishes (Poeciliidae: Poecilia and Gambusia) thrive in various watercourses with different concentrations of H2S. Previous studies have revealed pronounced genetic differentiation between different locally adapted populations in one species (Poecilia mexicana), pointing towards incipient speciation. In the present study, we examined female reproductive life-history traits in two species pairs: Gambusia sexradiata (from a nonsulfidic and a sulfidic habitat) and Gambusia eurystoma (sulfide-endemic), as well as P. mexicana (nonsulfidic and sulfidic) and Poecilia sulphuraria (sulfide endemic). We found convergent divergence of life-history traits in response to sulfide; most prominently, extremophile poeciliids exhibit drastically increased offspring size coupled with reduced fecundity. Furthermore, within each genus, this trend increased with increasing sulfide concentrations and was most pronounced in the two endemic sulfur-adapted species. We discuss the adaptive significance of large offspring size in toxic environments and propose that divergent life-history evolution may promote further ecological divergence through isolation by adaptation.
影响因子：
5.2
作者：
Hendry, Andrew P.;Nosil, Patrik;Rieseberg, Loren H.
通讯作者：
Rieseberg, Loren H.