Phylogenetic relationships, population genetics and hybridisation of two species of southern fur seal (Arctocephalus spp.)

摘要: This research investigated the phylogenetic relationships and population genetics of two species fur seal in order to provide a basis for study hybridisation these at Macquarie Island. The Antarctic (Arctocephalus gaze/la) subantarctic seals (Arctocepha/us tropicalis) occur throughout region Southern Ocean, hauling out on remote islands breed. Both were subject intense sealing activities 18th 19th centuries. competitive indiscriminate nature industry ensured that all populations greatly reduced size, with some becoming extinct. cessation early 20th century has allowed both recover number, recolonise across their former range. current range overlaps lies Crozet, Marion Island Hybridisation been reported low levels Island, higher situation is further complicated by presence an additional species, New Zealand forsteri) While this not breeding island, males participate process, hybrids being produced seeks apply molecular methods investigate occurring within context evolutionary recent history lesser extent, seal. The family Otariidae. include nine (Genera Arctocephalus Callorhinus), five sea lion Neophoca, Phocarctos, Eumetopias, Zalophus, Otaria). A 360 base pair cytochrome b gene maternally inherited mitochondrial genome was used primary analysis family, while 356 fragment control enhance resolution terminal nodes. traditional classification into two. subfamilies Arctocephalinae (fur seals) Otariinae (sea lioris) supported, as Cal/orhinus ursinus found be basal other taxa. four clades consistently observed through analyses conducted, it possible adequately resolve among clades. probably reflects rapid radiation taxa occurred about 3 million years ago. most closely related Australian Cape (A. pusillus) closest clearly resolved. However, there discrete specific differences between Antarctic, region, providing identification hybridising Island. The investigation level distribution genetic variation conducted using classes marker. commonly marker issues, due part relatively high rate mutation. Microsatellites are highly variable regions nuclear genome, bi-parental mode inheritance, natural complement genes. Given historic records indicate had passed bottlenecks result sealing, suspected may low. because have extreme stage past (eg. northern elephant seal, Mirounga angustirostris). Surprisingly, nucleotide diversities seals, determined (3.2% 4.8% respectively). exhibited 10 microsatellite loci generally (overall heterozygosity 0.54-0.62 three species), though loci. Despite overlapping allele size ranges loci, significant allelic genotypic differentiation (P < 0.000). Significant structure evident (