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Temporal patterns of fruit fly (Drosophila) evolution revealed by mutation clocks
Koichiro Tamura1, Sankar Subramanian, Sudhir Kumar
1Center for Evolutionary Functional Genomics, Arizona Biodesign Institute, and School of Life Sciences, Arizona State University, USA.
Molecular Biology and Evolution
|September 2, 2003
Summary
This study establishes a fruit fly molecular time scale using genomic mutation distances, revealing speciation timings for Drosophila melanogaster. The findings align with paleoclimate shifts and habitat fragmentation during the Cenozoic era.
Area of Science:
- Evolutionary Biology
- Genomics
- Molecular Evolution
Background:
- Drosophila melanogaster is a key model organism, but its speciation timing is unclear due to limited fossil and biogeographic data.
- Existing molecular clock methods are unreliable due to non-uniform substitution rates.
Purpose of the Study:
- To develop a novel methodology using genomic mutation distances to establish a fruit fly molecular time scale.
- To accurately date major speciation events in the evolution of Drosophila melanogaster.
Main Methods:
- Analysis of 2977 pairwise sequence comparisons from 176 nuclear genes.
- Development and application of a genomic mutation clock at a rate of 11.1 mutations per kilobase pair per Myr.
- Dating of speciation events based on calculated mutation distances.
Main Results:
- Established a fruit fly mutation clock rate.
- Dated key speciation events, including common ancestry with D. simulans at 5.4 MYA.
- Estimated divergence times for various Drosophila subgroups and groups, compatible with existing data.
Conclusions:
- The genomic mutation clock provides a robust method for dating fruit fly evolution.
- Inferred evolutionary timings correlate with paleoclimate changes and habitat fragmentation.
- This study offers a refined timeline for Drosophila melanogaster's evolutionary history.