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Undersampling taxa will underestimate molecular divergence dates: an example from the South american lizard clade
1Department of Biology, 8 Clarkson Avenue, Clarkson University, Potsdam, NY 13699, USA.
International Journal of Evolutionary Biology
|November 14, 2013
Summary
Undersampling species in molecular dating can lead to younger node age estimates. Maximizing taxon sampling and using accurate fossil calibrations are crucial for reliable divergence time estimates in evolutionary studies.
Area of Science:
- Evolutionary Biology
- Molecular Phylogenetics
- Computational Biology
Background:
- Estimating divergence times from molecular data is vital for evolutionary studies.
- Limited research exists on how taxon sampling affects molecular clock estimates.
Purpose of the Study:
- To investigate the impact of undersampling species diversity on node age estimates within the Liolaemini lizard clade.
- To evaluate the effects of different taxon sampling strategies and calibration numbers on molecular dating methods.
Main Methods:
- Phylogenetic analyses using penalized likelihood (PL) and Bayesian methods on a mitochondrial DNA (mtDNA) dataset.
- Applied various subsampling strategies for taxa and time calibrations to a densely sampled phylogeny of Iguanidae, including 92 Liolaemini species.
Main Results:
- Low taxon sampling resulted in younger node age estimates when using penalized likelihood with all calibrations.
- Bayesian and PL methods showed differing responses to the number of calibrations used; Bayesian ages increased with fewer calibrations, while PL ages decreased.
Conclusions:
- Maximizing taxon sampling, including outgroups, is essential to prevent underestimation of node ages.
- Employing more, well-vetted fossil calibrations improves the accuracy of divergence time estimates.
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