Department of Biology, Drexel University, Philadelphia 19104, Pennsylvania, USA.
BMC Evol Biol. 2015 Jan 21;15(1):1. doi: 10.1186/s12862-014-0274-0.
The mechanisms that underlie the diversification of tropical animals remain poorly understood, but new approaches that combine geo-spatial modeling with spatially explicit genetic data are providing fresh insights on this topic. Data about the diversification of tropical mammals remain particularly sparse, and vanishingly few opportunities exist to study endangered large mammals that increasingly exist only in isolated pockets. The chimpanzees of Cameroon represent a unique opportunity to examine the mechanisms that promote genetic differentiation in tropical mammals because the region is home to two chimpanzee subspecies: Pan troglodytes ellioti and P. t. trogolodytes. Their ranges converge in central Cameroon, which is a geographically, climatically and environmentally complex region that presents an unparalleled opportunity to examine the roles of rivers and/or environmental variation in influencing the evolution of chimpanzee populations.
We analyzed microsatellite genotypes and mtDNA HVRI sequencing data from wild chimpanzees sampled at a fine geographic scale across Cameroon and eastern Nigeria using a spatially explicit approach based upon Generalized Dissimilarity Modeling. Both the Sanaga River and environmental variation were found to contribute to driving separation of the subspecies. The importance of environmental variation differed among subspecies. Gene-environment associations were weak in P. t. troglodytes, whereas environmental variation was found to play a much larger role in shaping patterns of genetic differentiation in P. t. ellioti.
We found that both the Sanaga River and environmental variation likely play a role in shaping patterns of chimpanzee genetic diversity. Future studies using single nucleotide polymorphism (SNP) data are necessary to further understand how rivers and environmental variation contribute to shaping patterns of genetic variation in chimpanzees.
热带动物多样性形成的机制仍知之甚少，但结合地理空间建模与空间显式遗传数据的新方法为该主题提供了新的见解。关于热带哺乳动物多样性的数据仍然特别稀缺，几乎没有机会研究濒危的大型哺乳动物，这些动物越来越多地只存在于孤立的地区。喀麦隆的黑猩猩为研究促进热带哺乳动物遗传分化的机制提供了一个独特的机会，因为该地区有两个黑猩猩亚种：普通黑猩猩（Pan troglodytes ellioti）和普通黑猩猩指名亚种（P. t. trogolodytes）。它们的分布范围在喀麦隆中部重叠，该地区具有独特的地理、气候和环境复杂性，为研究河流和/或环境变化在影响黑猩猩种群进化中的作用提供了无与伦比的机会。
我们采用基于广义差异建模的空间显式方法，分析了在喀麦隆和尼日利亚东部的精细地理尺度上采集的野生黑猩猩的微卫星基因型和 mtDNA HVRI 测序数据。桑加雷河和环境变化都被发现对亚种的分离起到了推动作用。环境变化对两个亚种的影响程度不同。在普通黑猩猩指名亚种中，基因-环境的关联较弱，而在普通黑猩猩亚种中，环境变化在塑造遗传分化模式方面发挥了更大的作用。
我们发现，桑加雷河和环境变化可能都在塑造黑猩猩遗传多样性模式方面发挥了作用。未来需要使用单核苷酸多态性（SNP）数据的研究来进一步了解河流和环境变化如何有助于塑造黑猩猩的遗传变异模式。
Zotero 插件
