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What can DNA Tell us About the Cambrian Explosion?
1Centre for the Study of Evolution, School of Biological Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK.
Integrative and Comparative Biology
|June 18, 2011
Summary
Molecular data offers a powerful lens for studying evolutionary history, especially for non-fossilizing organisms. Recent studies address challenges in molecular dating, particularly concerning rate variations and their impact on diversification timelines.
Area of Science:
- Evolutionary biology
- Molecular evolution
- Phylogenetics
Background:
- Molecular data offers universality and abundance for exploring evolutionary history, independent of morphology.
- It is crucial for testing hypotheses on the tempo and mode of animal body plan evolution.
- Molecular phylogenies challenge fundamental assumptions in metazoan evolution and propose deep Precambrian origins for animal phyla.
Purpose of the Study:
- To examine the role of molecular data in understanding evolutionary history and testing hypotheses.
- To address criticisms and challenges in molecular dating, particularly temporal variation in evolutionary rates.
- To investigate the impact of adaptive radiations on molecular evolution rates and diversification dates.
Main Methods:
- Analysis of molecular phylogenies to reconstruct evolutionary history.
- Statistical frameworks for testing evolutionary hypotheses using molecular data.
- Examination of empirical evidence for rate variation in molecular evolution.
Main Results:
- Molecular data has led to re-evaluating assumptions about developmental characters and bauplan evolvability.
- Molecular dating suggests major animal kingdom divisions originated deep in the Precambrian.
- Challenges related to lineage-specific rate variation and estimation of molecular evolution rates have been largely addressed.
Conclusions:
- Molecular data provides a robust framework for evolutionary studies, including deep time.
- Temporal variation in molecular evolution rates, especially during radiations, remains a challenge for accurate diversification dating.
- Further development of rate-variable methods is crucial for refining molecular dating estimates.
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