Journal
MITOCHONDRIAL DNA
Volume 21, Issue 3-4, Pages 138-146Publisher
TAYLOR & FRANCIS LTD
DOI: 10.3109/19401736.2010.494727
Keywords
Mitochondrial DNA; whales; molecular clock; rate heterogeneity
Categories
Funding
- Australian Research Council
Ask authors/readers for more resources
Background and aims. There is extensive variation in substitution rates among metazoan mitochondrial genomes, including differences among lineages and among sites. Differences in substitution rates among lineages are routinely taken into account in molecular phylogenetic and dating analyses. However, this is rarely the case for differences in the lineage-specific patterns of rate variation among sites. Materials and methods. We analysed an alignment of 32 cetacean mitogenomes using a partitioned relaxed-clock approach, in which a separate relaxed-clock model was applied to each of the three codon positions of the protein-coding genes. Results. By comparing Bayes factors, we found overwhelming support for this model compared with a strict-clock model and less-complex models comprising fewer relaxed clocks. Our analyses reveal the presence of substantial rate heterogeneity among cetacean lineages, and that these patterns of variation differ between codon positions. However, we find no evidence of mitochondrial rate autocorrelation throughout the cetacean phylogeny. Conclusions. Our study confirms the feasibility of applying a partitioned relaxed-clock model to mitogenomic data, and suggests that molecular phylogenetic and dating analyses may be improved by the application of these models.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available