Arbeláez-Cortés Enrique, Milá Borja, Navarro-Sigüenza Adolfo G
Museo de Zoología, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Apartado Postal 70-399, México DF 04510, Mexico; Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, México DF 04510, Mexico.
Mol Phylogenet Evol. 2014 Jan;70:362-77. doi: 10.1016/j.ympev.2013.10.006. Epub 2013 Oct 18.
Among-species phylogeographic concordance provides insight into the common processes driving lineage divergence in a particular region. However, identifying the processes that caused phylogeographic breaks is not always straight forward, and inferring past environmental conditions in combination with documented geologic events is sometimes necessary to explain current patterns. We searched for concordant phylogeographic patterns and investigated their causes in three bird species (Momotus mexicanus, Melanerpes chrysogenys, and Passerina leclancherii) that belong to three different avian orders and are endemic to the northernmost range of the Neotropical dry forest. We obtained mitochondrial DNA (ND2 and COI or cyt b) and nuclear DNA (20454, GAPDH, MUSK, and TGFB) sequences for at least one locus from 162 individuals across all species and defined climatically stable areas using environmental niche model projections for the last 130,000 years to have a paleoenvironmental framework for the phylogeographic results. All three species showed marked phylogeographic structure, with breaks found in roughly similar areas, such as the border between the Mexican states of Guerrero and Oaxaca, and between southern Jalisco and Michoacán. Both of these regions are known biogeographic breaks among other taxa. Patterns of genetic diversity and differentiation were partially compatible with climatically stable areas. Coalescent analyses revealed recent population growth and estimated the deeper haplogroup divergence of all three taxa to have occurred within the last 600,000 years. The phylogeographic patterns found are noteworthy because they are maintained in a relatively small area for bird species with continuous ranges, and highlight a unique situation when compared to phylogeographic patterns found in other studies of Neotropical birds that have stressed the role of geographic barriers to explain intraspecific differentiation. Our results point to a scenario of population isolation resulting in the present phylogeographic structure, likely a result of historical climate fluctuations that have fragmented and reconnected the Neotropical dry forest. This study contributes to a growing body of evidence indicating active diversification of endemic lineages in the northern Neotropical dry forest region.
种间系统发育地理学的一致性为洞察驱动特定区域谱系分化的共同过程提供了线索。然而，确定导致系统发育间断的过程并非总是直截了当的，结合已记录的地质事件推断过去的环境条件有时对于解释当前模式是必要的。我们在三种鸟类（墨西哥绿咬鹃、黄斑拟啄木鸟和勒氏灯草鹀）中寻找一致的系统发育地理模式并研究其成因，这三种鸟属于三个不同的鸟类目，且是新热带干燥森林最北端范围内的特有物种。我们从所有物种的162个个体中至少一个位点获取了线粒体DNA（ND2和COI或细胞色素b）和核DNA（20454、GAPDH、MUSK和TGFB）序列，并使用过去13万年的环境生态位模型预测来定义气候稳定区域，以便为系统发育地理结果建立古环境框架。所有三个物种都表现出明显的系统发育地理结构，间断出现在大致相似的区域，比如墨西哥格雷罗州和瓦哈卡州之间的边界，以及哈利斯科州南部和米却肯州之间。这两个区域在其他分类群中都是已知的生物地理间断。遗传多样性和分化模式与气候稳定区域部分相符。溯祖分析揭示了近期的种群增长，并估计所有三个分类单元更深层次的单倍群分化发生在过去60万年之内。所发现的系统发育地理模式值得注意，因为它们在具有连续分布范围的鸟类物种的相对小区域内得以维持，并且与新热带鸟类其他研究中发现的强调地理障碍在解释种内分化中作用的系统发育地理模式相比，凸显了一种独特情况。我们的结果指向一种种群隔离导致当前系统发育地理结构的情形，这可能是历史气候波动使新热带干燥森林碎片化并重新连接的结果。这项研究为越来越多的证据做出了贡献，这些证据表明新热带干燥森林北部地区特有谱系的活跃分化。
