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Determinants of rate variation in mammalian DNA sequence evolution
L Bromham1, A Rambaut, P H Harvey
1Department of Zoology, University of Oxford, United Kingdom.
Journal of Molecular Evolution
|December 1, 1996
Summary
Molecular evolution rates vary across mammals. Slower molecular evolution correlates with longer generation times and larger body sizes, but not metabolic rate.
Area of Science:
- Evolutionary Biology
- Molecular Evolution
- Genomics
Background:
- Analyzing molecular evolution rates in mammals is challenging due to limited data and non-independent comparisons.
- Understanding factors influencing molecular evolution rates is crucial for evolutionary studies.
Purpose of the Study:
- To investigate the correlation between molecular evolution rates and generation time, metabolic rate, and body size in mammalian lineages.
- To utilize phylogenetically independent comparisons to overcome limitations in previous studies.
Main Methods:
- Comparative analysis of mitochondrial and nuclear genes (protein coding, rRNA, nontranslated sequences) from 61 mammal species.
- Correlation analyses between genetic distance and differences in body mass, generation time, and metabolic rate.
Main Results:
- A negative correlation was observed between substitution rates at fourfold degenerate sites and generation time for two out of three protein sequences.
- A relationship was found between molecular evolution rates and body size for two nuclear-encoded sequences.
- No significant effect of metabolic rate on the rate of molecular evolution was detected.
Conclusions:
- Generation time and body size are significant factors influencing molecular evolution rates in mammals.
- Metabolic rate does not appear to be a primary driver of variation in molecular evolution rates across mammalian species.
- Phylogenetically independent comparisons provide a robust framework for analyzing evolutionary rate variation.