Evolution of the Antarctic marine fauna: what can DNA and fossils tell us?

• Main Authors: J. M. Strugnell, K. Linse
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Drake Passage; The Antarctic; Antarc*; Icefish
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.484.3661; http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea079.pdf

Summary The opening of the Drake Passage, establishment of the Polar Front and the onset of cooling around the Eocene-Oligocene boundary have been recognised as the most significant events in shaping the recent Antarctic marine fauna. Orbitally-forced glacial cycles leading to loss of shelf habitat during glaciations may have been integral in determining extant biodiversity, including the establishment of regional isolation and diversification. Adaptive radiation of major clades, notably icefish, molluscs and crustaceans, occurred in isolation from the rest of the world. Cooler periods may have been associated with isolation and extinction of cold intolerant species but rapid evolution of groups that could adapt to extreme low temperatures. These cold-tolerant groups have radiated and there is evidence that some have invaded other parts of the world such as the deep seas. Modern techniques utilising DNA, fossil and biogeographical evidence can be used to give robust estimates to determine the dates of divergence and molecular rate. This sheds light onto the evolutionary history of the Antarctic marine fauna.