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Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin
Published on: August 14, 2018
Exploring the correlations between sequence evolution rate and phenotypic divergence across the Mammalian tree
Jan Janecka1, Bhanu Chowdhary, William Murphy
1Veterinary Integrative Biosciences, Texas A and M University, College Station, Texas, USA. jjanecka@cvm.tamu.edu
Journal of Biosciences
|October 31, 2012
Summary
Molecular clock studies reveal that sequence evolution rates vary. Phenotypic evolution, however, appears decoupled from sequence changes, driven by regulatory alterations rather than steady substitution accumulation.
Area of Science:
- Evolutionary biology
- Molecular evolution
- Genomics
Background:
- The molecular clock paradigm posits consistent sequence substitution rates for estimating lineage divergence.
- Relaxed molecular clock methods account for rate heterogeneity across lineages and genes.
- Sequence evolution rates correlate with life history traits but links to morphological evolution are less understood.
Purpose of the Study:
- To investigate the relationship between molecular and morphological evolution rates.
- To explore the mechanisms driving rapid functional radiations and phenotypic divergence.
- To challenge the hypothesis that phenotypic change results solely from steady substitution accumulation.
Main Methods:
- Review of recent studies on molecular evolution rates and life history traits.
- Comparative analysis of molecular and morphological evolution patterns across diverse lineages.
- Discussion of molecular mechanisms underlying functional divergence.
Main Results:
- Rates of molecular and morphological evolution are largely decoupled across diverse lineages.
- Rapid functional radiations and phenotypic divergence are not solely driven by steady sequence substitution.
- Mammalian lineages show vast functional divergence despite relatively slow sequence evolution.
Conclusions:
- Phenotypic divergence is likely driven by regulatory alterations, such as insertions/deletions in functional regions.
- These regulatory changes can rapidly fix, enabling rapid phenotypic leaps.
- Understanding molecular mechanisms behind functional diversity is key to evolutionary insights.
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