The origin of Antarctic ice shelf fauna, the timing of its emergence and the demographic stability of the fauna over time

目的是研究冰架下动物的分类、生物多样性、系统地理学和种群遗传模式，重点研究多毛纲动物。这将有助于为依赖冰架覆盖的动物的进化和人口历史所反映的冰架退缩和扩张提供独立的证据。南极冰盖流向海洋，最终在海洋中形成漂浮的冰川或冰架，覆盖在巨大的冰下空洞上。最大的冰架有法国那么大，它们是在300-100米厚的冰盖下的未开发的海洋。只有少数已发表的关于冰架下动物群的调查（Lipps et al., 1979; Post et al., 2007; Sugiyama et al., 2014），都没有遗传数据。冰架下动物群的系统发育起源至今尚不清楚。它是从附近的南极陆架物种进化而来的，还是从周围的深海移居而来，已经适应了能源匮乏的环境？（Neal et al . 2017）。可以通过系统发育和种群遗传分析来评估该动物群的进化起源和年龄以及人口统计学变化（Brasier et al., 2016; Brasier et al., 2017）。总之，这些新的遗传数据可以提供关于冰盖前进和后退时间的独立的、生物学的证据线。

The objective is to study the taxonomy, biodiversity, phylogeography and population genetic patterns of under-ice shelf fauna with a focus on polychaetes. This will help provide independent evidence for ice shelf retreats and expansions as reflected by the evolutionary and demographic history of fauna that depend on ice shelf cover.The Antarctic ice sheet drains towards and terminates in the ocean, where it forms floating glaciers, or ice shelves, overlying vast sub-ice cavities. The largest of the ice shelves are the size of France, and they are unexplored oceans underlying sheets of ice that are 300-100 m thick. There are only a handful of published investigations of under-ice shelf fauna (Lipps et al., 1979; Post et al., 2007; Sugiyama et al., 2014), none with genetic data. The phylogenetic origin of the under-ice shelf fauna is as of yet unknown. Did it evolve from nearby Antarctic shelf species or did elements of this fauna colonize from the surrounding deep sea, already adapted to an energy-poor environment? (Neal et al 2017). The evolutionary origin and age, as well as demographical changes to this fauna, can be assessed through phylogenetic and population genetic analyses (Brasier et al., 2016; Brasier et al., 2017). Together, these new genetic data can provide an independent, biological, line of evidence regarding the timing of ice-sheet advance and retreat.