Historical biogeography and phylogeny of monachine seals (Pinnipedia: Phocidae) based on mitochondrial and nuclear DNA data

• Published in: Journal of biogeography Vol. 32; no. 7; pp. 1267 - 1279
• Main Authors: Fyler, C. A., Reeder, T. W., Berta, A., Antonelis, G., Aguilar, A., Androukaki, E.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.07.2005; Blackwell Publishing; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Bayesian analysis; Biogeography; Biological and medical sciences; Datasets; Evolution; Fossils; Fundamental and applied biological sciences. Psychology; General aspects; Historical biogeography; Large Mammal Ecology and Biogeography; Mammalia; Marine; mixed model; Modeling; molecular divergence estimates; Monachinae; nonparametric rate smoothing; partitioned Bayesian inference; Phylogenetics; Phylogeny; Pinnipedia; seal biogeography; Seals; Synecology; Taxa; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Historical biogeography; Partition; Carnivora; partitioned Bayesian inference; molecular divergence estimates; Biogeography; Mitochondrial DNA; Phylogeny; nonparametric rate smoothing; Case history; Pinnipedia; Vertebrata; Mammalia; Geographic distribution; Mixed model; seal biogeography; Monachinae
• ISSN: 0305-0270; 1365-2699
• DOI: 10.1111/j.1365-2699.2005.01281.x

Aim To determine the origin and diversification of monachine seals using a phylogenetic framework. Methods Molecular sequence data from three mitochondrial genes (cyt b, ND1 and 12S), and one nuclear marker (an intron from the α-lactalbumin gene) were examined from all extant species of monachine seals. Maximum likelihood and partitioned Bayesian inference were used to analyse separate and combined (mitochondrial + nuclear) data sets. Divergence times were estimated from the resultant phylogeny using nonparametric rate smoothing as implemented by the program r8s. Results Mirounga, Monachus and the Lobodontini form three well-supported clades within a monophyletic Monachinae. Lobodontini + Mirounga form a clade sister to Monachus. Molecular divergence dates indicate that the first split within the Monachinae (Lobodontini + Mirounga clade and Monachus) occurred between 11.8 and 13.8 Ma and Mirounga, Monachus and the Lobodontini originated 2.7-3.4, 9.1-10.8 and 10.0-11.6 Ma, respectively. Main conclusions Two main clades exist within Monachinae, Monachus and Lobodontini + Mirounga. Monachus, a warm water clade, originated in the North Atlantic and maintained the temperate water affinities of their ancestors as they diversified in the subtropic regions of the Northern Hemisphere. The cold-water clade, Lobodontini + Mirounga, dispersed southward to the cooler climates of the Southern Hemisphere. The Lobodontini continued south until reaching the Antarctic region where they diversified into the present-day fauna. Mirounga shows an anti-tropical distribution either reflective of a once cosmopolitan range that was separated by warming waters in the tropics or of transequatorial dispersal.