Maggs Christine A, Castilho Rita, Foltz David, Henzler Christy, Jolly Marc Taimour, Kelly John, Olsen Jeanine, Perez Kathryn E, Stam Wytze, Väinölä Risto, Viard Frédérique, Wares John
School of Biological Sciences, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, United Kingdom.
Ecology. 2008 Nov;89(11 Suppl):S108-22. doi: 10.1890/08-0257.1.
A goal of phylogeography is to relate patterns of genetic differentiation to potential historical geographic isolating events. Quaternary glaciations, particularly the one culminating in the Last Glacial Maximum approximately 21 ka (thousands of years ago), greatly affected the distributions and population sizes of temperate marine species as their ranges retreated southward to escape ice sheets. Traditional genetic models of glacial refugia and routes of recolonization include these predictions: low genetic diversity in formerly glaciated areas, with a small number of alleles/haplotypes dominating disproportionately large areas, and high diversity including "private" alleles in glacial refugia. In the Northern Hemisphere, low diversity in the north and high diversity in the south are expected. This simple model does not account for the possibility of populations surviving in relatively small northern periglacial refugia. If these periglacial populations experienced extreme bottlenecks, they could have the low genetic diversity expected in recolonized areas with no refugia, but should have more endemic diversity (private alleles) than recently recolonized areas. This review examines evidence of putative glacial refugia for eight benthic marine taxa in the temperate North Atlantic. All data sets were reanalyzed to allow direct comparisons between geographic patterns of genetic diversity and distribution of particular clades and haplotypes including private alleles. We contend that for marine organisms the genetic signatures of northern periglacial and southern refugia can be distinguished from one another. There is evidence for several periglacial refugia in northern latitudes, giving credence to recent climatic reconstructions with less extensive glaciation.
系统发育地理学的一个目标是将遗传分化模式与潜在的历史地理隔离事件联系起来。第四纪冰川作用，尤其是大约21千年前（ka，千年）达到末次盛冰期的那次冰川作用，极大地影响了温带海洋物种的分布和种群规模，因为它们的分布范围向南退缩以躲避冰盖。传统的冰川避难所和重新定殖路线的遗传模型包括这些预测：以前被冰川覆盖的地区遗传多样性低，少数等位基因/单倍型不成比例地占据大片区域，而冰川避难所则具有高多样性，包括“私有”等位基因。在北半球，预计北部多样性低而南部多样性高。这个简单的模型没有考虑到种群在相对较小的北半球冰缘避难所中存活的可能性。如果这些冰缘种群经历了极端瓶颈，它们可能具有在没有避难所的重新定殖地区预期的低遗传多样性，但应该比最近重新定殖的地区具有更多的特有多样性（私有等位基因）。这篇综述研究了温带北大西洋八个底栖海洋类群假定的冰川避难所的证据。对所有数据集重新进行了分析，以便直接比较遗传多样性的地理模式与特定进化枝和单倍型（包括私有等位基因）的分布。我们认为，对于海洋生物来说，北半球冰缘和南部避难所的遗传特征可以相互区分。有证据表明在北纬地区存在几个冰缘避难所，这为近期冰川作用范围较小的气候重建提供了支持。
