The Antarctic biota is highly endemic, and the diversity and abundance of taxonomic groups differ from elsewhere in the world. Such characteristics have resulted from evolution in isolation in an increasingly extreme environment over the last 100 Myr. Studies on Antarctic species represent some of the best examples of natural selection at the molecular, structural and physiological levels. Analyses of molecular genetics data are consistent with the diversity and distribution of marine and terrestrial taxa having been strongly influenced by geological and climatic cooling events over the last 70 Myr. Such events have resulted in vicariance driven by continental drift and thermal isolation of the Antarctic, and in pulses of species range contraction into refugia and subsequent expansion and secondary contact of genetically distinct populations or sister species during cycles of glaciation. Limited habitat availability has played a major role in structuring populations of species both in the past and in the present day. For these reasons, despite the apparent simplicity or homogeneity of Antarctic terrestrial and marine environments, populations of species are often geographically structured into genetically distinct lineages. In some cases, genetic studies have revealed that species defined by morphological characters are complexes of cryptic or sibling species. Climate change will cause changes in the distribution of many Antarctic and sub-Antarctic species through affecting population-level processes such as life history and dispersal.
Hustings for City councillor candidates were held prior to OUSU Council on Wednesday of 1st Week in Magdalen College Auditorium. There were candidates present representing the Conservatives, the Greens, Labour, the Liberal Democrats and the Monster Raving Loony Party.Four out of the five candidates on the panel had either studied at, or are currently studying at Oxford. Of those currently studying at Oxford, Aled Jones is running in Holywell Ward representing Labour, while Maryam Ahmed is as a Conservative running in Carfax Ward.The husts were characterised by consensus, with candidates being quick to agree with the people who asked questions, making it somewhat difficult to distinguish between them. Oxford Covered Market, the County Council’s homelessness cuts and the City Council’s policies affecting student housing in Oxford were all discussed, as well as the Mad Hatter revealing his unorthodox policy for everyone to marry a foreigner within the year.In response to one question, all candidates, except for The Mad Hatter, were willing to identify as feminists.In summary, the panel appeared to largely agree, with all candidates expressing progressive political positions.The full C+ investigation can be found here.