Biogeography of Circum-Antarctic springtails.

• Published in: Molecular Phylogenetics and Evolution
• Main Authors: McGraughran, A, Stevens, M, Holland, BR
• Format: Article in Journal/Newspaper
• Language: English
• Published: Academic Press Inc Elsevier Science 2010
• Subjects: Biological Sciences; Evolutionary Biology; Biogeography and Phylogeography; Antarctic; Southern Ocean; Antarc*; Antarctica; Springtail
• Online Access: https://doi.org/10.1016/j.ympev.2010.06.003; http://www.ncbi.nlm.nih.gov/pubmed/20558307; http://ecite.utas.edu.au/65030

We examine the effects of isolation over both ancient and contemporary timescales on evolutionarydiversification and speciation patterns of springtail species in circum-Antarctica, with special focus onmembers of the genus Cryptopygus (Collembola, Isotomidae).We employ phylogenetic analysis of mitochondrial DNA (cox1), and ribosomal DNA (18S and 28S)genes in the programmes MrBayes and RAxML. Our aims are twofold: (1) we evaluate existing taxonomyin light of previous work which found dubious taxonomic classification in several taxa based on cox1analysis; (2) we evaluate the biogeographic origin of our chosen suite of springtail species based on dispersal/vicariance scenarios, the magnitude of genetic divergence among lineages and the age and accessibilityof potential habitat.The dubious taxonomic characterisation of Cryptopygus species highlighted previously is confirmed byour multi-gene phylogenetic analyses. Specifically, according to the current taxonomy, Cryptopygus antarcticussubspecies are not completely monophyletic and neither are Cryptopygus species in general. Weshow that distribution patterns among species/lineages are both dispersal- and vicariance-driven. Episodesof colonisation appear to have occurred frequently, the routes of which may have followed currentsin the Southern Ocean. In several cases, the estimated divergence dates among species correspond wellwith the timing of terrestrial habitat availability.We conclude that these isotomid springtails have a varied and diverse evolutionary history in the circum-Antarctic that consists of both ancient and recent elements and is reflected in a dynamic contemporaryfauna.