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Model-based multi-locus estimation of decapod phylogeny and divergence times
Megan L Porter1, Marcos Pérez-Losada, Keith A Crandall
1Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA. Mlp65@nm.byu.edu
Molecular Phylogenetics and Evolution
|August 23, 2005
Summary
This study reconstructs decapod crustacean evolutionary history using molecular data, revealing their rapid radiation and early origin. Molecular phylogenies challenge previous morphological hypotheses, providing new insights into decapod relationships.
Area of Science:
- * Molecular Phylogenetics
- * Crustacean Evolution
- * Systematics
Background:
- * Previous phylogenetic studies of decapod crustaceans using morphological data yielded conflicting results.
- * Molecular phylogenetic data has not been comprehensively used to estimate relationships among major decapod infraorders.
Purpose of the Study:
- * To infer phylogenetic relationships among decapod infraorders using multi-locus molecular data.
- * To estimate divergence times for major decapod lineages.
- * To test alternative hypotheses of decapod evolution.
Main Methods:
- * Phylogenetic analyses using 16S mtDNA, 18S and 28S rRNA, and histone H3 gene sequences.
- * Reconstruction of phylogenies using maximum likelihood and Bayesian inference methods.
- * Divergence time estimation using multi-locus Bayesian and likelihood heuristic rate-smoothing methods with fossil calibrations.
Main Results:
- * Phylogenetic analyses recovered seven decapod infraorders and two suborders as monophyletic.
- * Anomala and Brachyura were found to be basal to other 'Reptantia', rejecting morphology-based hypotheses.
- * Decapoda originated earlier than 437 MYA, with rapid radiation and all major lineages present by 325 MYA.
Conclusions:
- * Molecular data provides a robust framework for understanding decapod phylogeny.
- * The study refines our understanding of decapod evolutionary history and divergence times.
- * Fossil calibration strategies significantly impact divergence time estimations.