Evaluating the hypothesis of Pleistocene refugia for mammals in the Cuatro Cienegas region
Periodo de realización: 0001/01/01 al 2019/01/01
Tipo: Capítulo de libro
Lugar(es) de estudio: Cuatrociénegas, Coah., México
Resumen: "The region of Cuatro Cienegas (CC) in the state of Coahuila Mexico is a very diverse ecosystem with high endemism of flora and fauna. It is included in the RAMSAR list of wetlands and considered as a priority area for conservation by the WWF. This site is located within the Chihuahuan Desert in an isolated area surrounded by the Sierra Madre Oriental and Sierra del Carmen. A previous study by Contreras-Balderas et al. (2007) found 39 mammalian species occurring in CC Basin Natural Protected Area, 30 of which are widespread. These authors concluded that there has been long-term environmental stability in this area, based on archeological records. In addition, the mammalian biota found in this area is an admixture between the biotas from the Chihuahuan biotic province and the Tamaulipeca province. Therefore, the aim of this study is to describe the biogeographic patterns of the mammals that distribute in CC region to determine whether this site was an important area of refuge during Pleistocene’s climate pulses, and to deepen our knowledge of the mammalian biota of the CC region. We obtained ecological niche models (ENMs) and projected them into past environmental conditions, Last Maximum Glacial (LMG) and Last Inter Glacial (LIG), to determine whether this area could have constituted a refuge area for the mammalian species. Besides, we conducted a review on the phylogeographic studies of these species to determine whether or not CC region could have been a Pleistocene refuge for mammalian species. Accordingly, we expect that species that refuge in CC region will show high genetic variation in this area, while species that were not present in the area during the Pleistocene will show lower levels of genetic variation. According to our results, CC region was an important area of refuge during Pleistocene climatic changes, specifically over the Sierra la Madera and Sierra San Marcos. Most mammal species of CC region are widespread. Results from past ENMs and phylogeographic analyses were consistent, except for five species of rodents, which did not conform to expected patterns of genetic diversity and changes in their distribution. Most reviewed analyses failed to include an adequate sample size for Mexican populations. Therefore, conducting phylogeographic studies of these mammals in the Chihuahuan desert is fundamental for understanding the dynamics that determined its biodiversity."