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Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
Molecular clocks: when times are a-changin'
1Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
Trends in Genetics : TIG
|December 17, 2005
Summary
Molecular clock rates vary over time, with short-term mutation rates differing from long-term substitution rates. This time dependency explains discrepancies in evolutionary dating and necessitates re-evaluating recent divergence event studies.
Area of Science:
- Evolutionary biology
- Molecular evolution
- Genetics
Background:
- The molecular clock is crucial for dating evolutionary events.
- Discrepancies exist between molecular, paleontological, and archaeological dates.
- High mutation rates from pedigree studies are debated.
Purpose of the Study:
- To address debates surrounding molecular clock dating and mutation rates.
- To introduce and examine the "time dependency of molecular rates" hypothesis.
- To reassess evolutionary timescales and divergence events.
Main Methods:
- Reviewing existing data on molecular evolution and mutation rates.
- Applying the "time dependency of molecular rates" hypothesis to reconcile disparities.
- Analyzing the impact of this hypothesis on various evolutionary fields.
Main Results:
- Short-term mutation rates and long-term substitution rates are not constant.
- A monotonic decline from mutation to substitution rates is proposed.
- Extrapolating molecular rates across different timescales leads to invalid date estimates.
Conclusions:
- The "time dependency of molecular rates" resolves major debates in molecular clock dating.
- Human evolution, animal domestication, and conservation genetics studies require re-evaluation.
- Many studies on recent divergence events may need revision based on this time dependency.
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