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Published on: January 13, 2017
[Molecular dating in the genomic era]
Emmanuel J P Douzery1, Frédéric Delsuc, Hervé Philippe
1Laboratoire de Paléontologie, Phylogénie et Paléobiologie-CC064, Institut des Sciences de l'Evolution UMR 5554/CNRS, Université Montpellier II, place E. Bataillon, 34095 Montpellier Cedex 05, France. douzery@isem.univ-montp2.fr
Medecine Sciences : M/S
|April 7, 2006
Summary
Molecular dating uses DNA and protein sequences to estimate species evolution timelines. Recent advances overcome challenges like limited data and rate variations, refining evolutionary event dating.
Area of Science:
- Evolutionary Biology
- Molecular Phylogenetics
- Paleogenomics
Context:
- Reconstructing Earth's evolutionary history relies on comparing DNA and protein sequences of extant species.
- Phylogenetic trees from molecular data reveal evolutionary affinities and estimate species origin and diversification times.
- Molecular dating assumes a constant rate of molecular change (molecular clock hypothesis) for absolute divergence time estimation with paleontological calibrations.
Purpose:
- To address limitations in molecular dating, including restricted gene/organism sampling, scarce fossil records, and variable evolutionary rates.
- To present recent advancements in molecular dating methodologies.
- To illustrate the application of these improved methods with examples from animal and mammal diversification.
Summary:
- Enhanced molecular dating employs larger datasets (more genes, species) and improved fossil calibration integration.
- Relaxed molecular clock approaches incorporate models of molecular rate variation to account for evolutionary rate heterogeneity.
- These advancements refine estimates, suggesting animal diversification occurred 642-761 million years ago and mammal diversification around 100 million years ago.
Impact:
- Provides more accurate and robust estimations of evolutionary timelines and divergence events.
- Refines our understanding of major evolutionary transitions, such as the origin of bilaterian metazoans and placental mammals.
- Facilitates deeper insights into the tempo and mode of life's evolution on Earth.
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