Testing relative evolutionary rates and estimating divergence times among six genera of Rhizophoraceae using cpDNA and nrDNA sequences

2000 ◽  
Vol 45 (11) ◽  
pp. 1011-1015 ◽  
Author(s):  
Yang Zhong ◽  
Suhua Shi ◽  
Xianhua Tang ◽  
Yelin Huang ◽  
Fengxiao Tan ◽  
...  
Keyword(s):  
Evolutionary Rates ◽  
Divergence Times

scholarly journals Theoretical foundation of the RelTime method for estimating divergence times from variable evolutionary rates

2017 ◽  
Author(s):  
Koichiro Tamura ◽  
Qiqing Tao ◽  
Sudhir Kumar
Keyword(s):  
Relative Rate ◽  
Molecular Data ◽  
Evolutionary Rates ◽  
Divergence Times ◽  
Computationally Efficient ◽  
Molecular Sequence ◽  
Branch Lengths ◽  
Variable Evolutionary Rates ◽  
Relationship Of ◽  
The Relationship

AbstractRelTime estimates divergence times by relaxing the assumption of a strict molecular clock in a phylogeny. It showed excellent performance in estimating divergence times for both simulated and empirical molecular sequence datasets in which evolutionary rates varied extensively throughout the tree. RelTime is computationally efficient and scales well with increasing size of datasets. Until now, however, RelTime has not had a formal mathematical foundation. Here, we show that the basis of the RelTime approach is a relative rate framework (RRF) that combines comparisons of evolutionary rates in sister lineages with the principle of minimum rate change between an evolutionary lineage and its descendants. We present analytical solutions for estimating relative lineage rates and divergence times under RRF. We also discuss the relationship of RRF with other approaches, including the Bayesian framework. We conclude that RelTime will be also useful for phylogenies with branch lengths derived not only from molecular data, but also morphological and biochemical traits.

scholarly journals RelTime relaxes the strict molecular clock throughout the phylogeny

2017 ◽  
Author(s):  
Fabia U. Battistuzzi ◽  
Qiqing Tao ◽  
Lance Jones ◽  
Koichiro Tamura ◽  
Sudhir Kumar
Keyword(s):  
Molecular Phylogeny ◽  
Molecular Clock ◽  
Evolutionary Rates ◽  
Molecular Dating ◽  
Divergence Times ◽  
Similar Time ◽  
Time Estimates ◽  
Theoretical Analyses ◽  
Strict Molecular Clock ◽  
Median Rate

AbstractThe RelTime method estimates divergence times when evolutionary rates vary among lineages. Theoretical analyses show that RelTime relaxes the strict molecular clock throughout a molecular phylogeny, and it performs well in the analysis of empirical and computer simulated datasets in which evolutionary rates are variable. Lozano-Fernandez et al. (2017) found that the application of RelTime to one metazoan dataset (Erwin et al. 2011) produced equal rates for several ancient lineages, which led them to speculate that RelTime imposes a strict molecular clock for deep animal divergences. RelTime does not impose a strict molecular clock. The pattern observed by Lozano-Fernandez et al. (2017) was a result of the use of an option to assign the same rate to lineages in RelTime when the rates are not statistically significantly different. The median rate difference was 5% for many deep metazoan lineages for Erwin et al. (2011) dataset, so the rate equality was not rejected. In fact, RelTime analysis with and without the option to test rate differences produced very similar time estimates. We found that the Bayesian time estimates vary widely depending on the root priors assigned, and that the use of less restrictive priors produce Bayesian divergence times that are concordant with those from RelTime for Erwin et al. (2011) dataset. Therefore, it is prudent to discuss Bayesian estimates obtained under a range of priors in any discourse about molecular dating, including method comparisons.

The range of sampling times affects Zika virus evolutionary rates and divergence times

2019 ◽  
Vol 164 (12) ◽  
pp. 3027-3034
Author(s):  
Lucia P. Barzilai ◽  
Carlos G. Schrago
Keyword(s):  
Zika Virus ◽  
Evolutionary Rates ◽  
Divergence Times ◽  
Sampling Times

scholarly journals Sphenodontian phylogeny and the impact of model choice in Bayesian morphological clock estimates of divergence times and evolutionary rates

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Tiago R. Simões ◽  
Michael W. Caldwell ◽  
Stephanie E. Pierce
Keyword(s):  
Evolutionary History ◽  
Evolutionary Rates ◽  
Morphological Data ◽  
Divergence Times ◽  
Evolutionary Trees ◽  
Model Choice ◽  
Rates Of Evolution ◽  
History Of ◽  
Living Species ◽  
The Impact

Abstract Background The vast majority of all life that ever existed on earth is now extinct and several aspects of their evolutionary history can only be assessed by using morphological data from the fossil record. Sphenodontian reptiles are a classic example, having an evolutionary history of at least 230 million years, but currently represented by a single living species (Sphenodon punctatus). Hence, it is imperative to improve the development and implementation of probabilistic models to estimate evolutionary trees from morphological data (e.g., morphological clocks), which has direct benefits to understanding relationships and evolutionary patterns for both fossil and living species. However, the impact of model choice on morphology-only datasets has been poorly explored. Results Here, we investigate the impact of a wide array of model choices on the inference of evolutionary trees and macroevolutionary parameters (divergence times and evolutionary rates) using a new data matrix on sphenodontian reptiles. Specifically, we tested different clock models, clock partitioning, taxon sampling strategies, sampling for ancestors, and variations on the fossilized birth-death (FBD) tree model parameters through time. We find a strong impact on divergence times and background evolutionary rates when applying widely utilized approaches, such as allowing for ancestors in the tree and the inappropriate assumption of diversification parameters being constant through time. We compare those results with previous studies on the impact of model choice to molecular data analysis and provide suggestions for improving the implementation of morphological clocks. Optimal model combinations find the radiation of most major lineages of sphenodontians to be in the Triassic and a gradual but continuous drop in morphological rates of evolution across distinct regions of the phenotype throughout the history of the group. Conclusions We provide a new hypothesis of sphenodontian classification, along with detailed macroevolutionary patterns in the evolutionary history of the group. Importantly, we provide suggestions to avoid overestimated divergence times and biased parameter estimates using morphological clocks. Partitioning relaxed clocks offers methodological limitations, but those can be at least partially circumvented to reveal a detailed assessment of rates of evolution across the phenotype and tests of evolutionary mosaicism.

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