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Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin
Published on: August 14, 2018
Higher-level salamander relationships and divergence dates inferred from complete mitochondrial genomes
1Department of Integrative Biology, Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720-3160, USA. alarzhang@gmail.com
Molecular Phylogenetics and Evolution
|July 15, 2009
Summary
This study resolves salamander family relationships using mitochondrial genomes, revealing key evolutionary divergences and origins. It confirms internally fertilizing salamanders as a clade and suggests Sirenidae as the earliest diverging group.
Area of Science:
- * Evolutionary Biology
- * Genomics
- * Herpetology
Background:
- * Phylogenetic relationships among salamander families are complex and difficult to resolve due to rapid early divergence.
- * Limited mitochondrial genome data exists for several salamander families, hindering comprehensive phylogenetic analysis.
Purpose of the Study:
- * To reconstruct the evolutionary history and phylogenetic relationships of all salamander families using complete mitochondrial genomes.
- * To investigate the evolutionary timescale and ancestral distribution of living salamanders.
Main Methods:
- * Sequencing and analysis of seven new complete mitochondrial genomes from five salamander families.
- * Phylogenetic analyses using whole mitogenome sequences and deduced amino acid sequences.
- * Bayesian phylogenetic inference with fossil calibration and ancestral area reconstruction.
Main Results:
- * Well-resolved phylogenetic topologies supporting the monophyly of all salamander families, including Proteidae.
- * Confirmation of internally fertilizing salamanders as a monophyletic clade with two distinct subclades.
- * Support for Sirenidae as the sister-group to all other salamanders, contradicting some nuclear gene analyses.
- * Revised evolutionary timescales indicating amphibian diversification in the Late Carboniferous to Early Permian and salamander origin in the Early Jurassic.
- * Ancestral area reconstruction suggests a Laurasian origin for the common ancestor of living salamanders.
Conclusions:
- * Mitogenomic data provides robust resolution for salamander phylogeny, clarifying family relationships.
- * The evolutionary timescale for salamanders suggests a later origin and diversification than some previous estimates.
- * Understanding salamander evolution requires integrating diverse data sources, including mitochondrial and nuclear genomes.
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