Diversification patterns in Boeckella

Aim: We investigated evolutionary relationships and biogeographical patterns within the genus Boeckella to evaluate: 1) whether its current widespread distribution in the Southern Hemisphere is due to recent long-distance dispersal or long-term diversification; and 2) the age and origin of sub-Antarctic and Antarctic Boeckella species, with particular focus on the most widely distributed species: B. poppei.

Location: South America, sub-Antarctic islands, maritime Antarctica, continental Antarctica and Australasia.

Methods: To reconstruct phylogenetic patterns of Boeckella, we used molecular sequence data collected from 12 regions, and applied Bayesian and Maximum Likelihood analyses using multiple loci. We also estimated divergence times and reconstructed ancestral ranges using two different models of species evolution.

Results: Phylogenetic analyses and divergence time estimates suggested that Boeckella originated on the Gondwanan supercontinent and initially split into two ma...