Betancourt-Resendes Isai, Pérez-Rodríguez Rodolfo, Piller Kyle R, Domínguez-Domínguez Omar
CONAHCYT-Laboratorio de Ecología y Diversidad Faunística, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico.
PIDCB, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacan, Mexico.
PeerJ. 2024 Dec 12;12:e18256. doi: 10.7717/peerj.18256. eCollection 2024.
Understanding the processes that influence distribution of organisms is a major goal in evolutionary biology. Speciation in freshwater fishes is mainly associated with the "island-like" model of evolution, in which the formation of land barriers between different hydrographic basins interrupts gene flow and promotes isolation. Freshwater fish therefore provide an excellent model system for macro- and micro-evolutionary studies. The Mesa Silverside, , is one of the most widespread freshwater fish species in the Mexican Plateau, a geologically complex physiographic region with a long history of genesis, destruction and compartmentalization of hydrographic basins that has promoted the dispersal and isolation of freshwater fishes.
We used mitochondrial ( and ) and nuclear (first intron of the ribosomal protein S7) data and used phylogeographic and coalescent based methods to elucidate the evolutionary history of throughout its distributional range on the Mexican Plateau.
The results obtained in the present study revealed that consists of two main genetic groups with geographical correspondence. Clade I occur exclusively in north-western basin and shows population structure. Clade II is widely distributed across the west, central and eastern basins without population structure. The split between these two main clades was estimated at 1.4 Mya. This cladogenetic event may be associated with the allopatric process promoted by the fragmentation and compartmentalization of hydrographic basins induced by the geological and climatic history of the Mexican Plateau.
了解影响生物分布的过程是进化生物学的一个主要目标。淡水鱼类的物种形成主要与“岛屿状”进化模式相关，在这种模式中，不同水文流域之间陆地屏障的形成会中断基因流动并促进隔离。因此，淡水鱼为宏观和微观进化研究提供了一个极好的模型系统。梅萨银汉鱼是墨西哥高原分布最广的淡水鱼物种之一，墨西哥高原是一个地质复杂的地貌区域，水文流域有着漫长的形成、破坏和分隔历史，这促进了淡水鱼的扩散和隔离。
我们使用了线粒体（和）和核（核糖体蛋白S7的第一个内含子）数据，并采用系统发育地理学和基于溯祖理论的方法来阐明梅萨银汉鱼在墨西哥高原整个分布范围内的进化历史。
本研究获得的结果表明，梅萨银汉鱼由两个具有地理对应关系的主要遗传群体组成。分支I仅出现在西北流域，并呈现出种群结构。分支II广泛分布于西部、中部和东部流域，没有种群结构。这两个主要分支之间的分化估计发生在140万年前。这一物种形成事件可能与墨西哥高原地质和气候历史导致的水文流域破碎化和分隔所促进的异域过程有关。
