Phylogeny and Phylogeography of Eudorylaimus in Victoria Land, Antarctica

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Antarctica is known to have less biologically diverse soils than the soils on most of Earth which are too biologically diverse to identify all species present and evaluate their evolutionary relationships. Within the soils of the Victoria Land region of Antarctica, nematoda is the largest and most significant phylum present therefore playing a fundamental role in the ecosystem. While of great importance to the ecosystem of the dry valleys of Antarctica, little has been done in regards to forming the phylogeny of Antarctic nematodes. Using soil samples collected from different locations of Victoria Land, I set out to test a previously made hypothesis that ancestral lineages of endemic species to Antarctica come from southern locations. My focus was on the genus Eudorylaimus which previously had 3 species identified within northern and central Victoria Land. I performed DNA extraction using a worm lysis buffer, then amplified the ITS1 region of ribosomal DNA using 5.8s and 18s primers for polymerase chain reaction. I then sequenced these regions of DNA using BigDye cycle sequencing. Using the ITS1 region of ribosomal DNA, I made a phylogenetic tree depicting the relationship between the Eudorylaimus collected at different locations throughout Victoria Land. I found four distinct lineages of Eudorylaimus. The hypothesis of ancestral lineages emerging from southern locations was confirmed. From my data, gene flow between different populations within the dry valleys is present.