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

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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.