García-Vázquez David, Bilton David T, Foster Garth N, Ribera I
Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Maritim de la Barceloneta 37, 08003 Barcelona, Spain.
Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
Mol Phylogenet Evol. 2017 Sep;114:122-136. doi: 10.1016/j.ympev.2017.06.007. Epub 2017 Jun 15.
Quaternary glacial cycles drove major shifts in both the extent and location of the geographical ranges of many organisms. During glacial maxima, large areas of central and northern Europe were inhospitable to temperate species, and these areas are generally assumed to have been recolonized during interglacials by range expansions from Mediterranean refugia. An alternative is that this recolonization was from non-Mediterranean refugia, in central Europe or western Asia, but data on the origin of widespread central and north European species remain fragmentary, especially for insects. We studied three widely distributed lineages of freshwater beetles (the Platambus maculatus complex, the Hydraena gracilis complex, and the genus Oreodytes), all restricted to running waters and including both narrowly distributed southern endemics and widespread European species, some with distributions spanning the Palearctic. Our main goal was to determine the role of the Pleistocene glaciations in shaping the diversification and current distribution of these lineages. We sequenced four mitochondrial and two nuclear genes in populations drawn from across the ranges of these taxa, and used Bayesian probabilities and Maximum Likelihood to reconstruct their phylogenetic relationships, age and geographical origin. Our results suggest that all extant species in these groups are of Pleistocene origin. In the H. gracilis complex, the widespread European H. gracilis has experienced a rapid, recent range expansion from northern Anatolia, to occupy almost the whole of Europe. However, in the other two groups widespread central and northern European taxa appear to originate from central Asia, rather than the Mediterranean. These widespread species of eastern origin typically have peripherally isolated forms in the southern Mediterranean peninsulas, which may be remnants of earlier expansion-diversification cycles or result from incipient isolation of populations during the most recent Holocene expansion. The accumulation of narrow endemics of such lineages in the Mediterranean may result from successive cycles of range expansion, with subsequent speciation (and local extinction in glaciated areas) through multiple Pleistocene climatic cycles.
第四纪冰期循环推动了许多生物地理分布范围在广度和位置上的重大变化。在冰期极盛期，欧洲中部和北部的大片地区不适宜温带物种生存，一般认为这些地区在间冰期是通过来自地中海避难所的范围扩张而重新被殖民的。另一种可能性是这种重新殖民来自中欧或西亚的非地中海避难所，但关于广泛分布的中欧和北欧物种的起源数据仍然零碎，尤其是对于昆虫而言。我们研究了淡水甲虫的三个广泛分布的谱系（黄斑扁甲复合体、纤细水龟甲复合体和奥氏水龟属），它们都局限于流水环境，包括分布狭窄的南方特有种和广泛分布的欧洲物种，有些物种的分布跨越古北区。我们的主要目标是确定更新世冰川作用在塑造这些谱系的多样化和当前分布中的作用。我们对从这些分类群的分布范围内采集的种群中的四个线粒体基因和两个核基因进行了测序，并使用贝叶斯概率和最大似然法来重建它们的系统发育关系、年龄和地理起源。我们的结果表明，这些类群中的所有现存物种都起源于更新世。在纤细水龟甲复合体中，广泛分布于欧洲的纤细水龟甲最近经历了一次快速的范围扩张，从安纳托利亚北部扩展到几乎占据了整个欧洲。然而，在其他两个类群中，广泛分布的中欧和北欧分类单元似乎起源于中亚，而不是地中海。这些起源于东部的广泛分布物种通常在地中海半岛南部有边缘隔离的形态，这可能是早期扩张 - 多样化循环的残余，或者是在最近全新世扩张期间种群开始隔离的结果。这些谱系在地中海地区狭窄特有种的积累可能是由于范围扩张的连续循环，随后通过多个更新世气候循环形成物种形成（以及在冰川地区的局部灭绝）。
