Cargando…
Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling
Large-scale phylogenies provide a valuable source to study background diversification rates and investigate if the rates have changed over time. Unfortunately most large-scale, dated phylogenies are sparsely sampled (fewer than 5% of the described species) and taxon sampling is not uniform. Instead,...
Autor principal: | |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2014
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3882215/ https://www.ncbi.nlm.nih.gov/pubmed/24400082 http://dx.doi.org/10.1371/journal.pone.0084184 |
_version_ | 1782298324171227136 |
---|---|
author | Höhna, Sebastian |
author_facet | Höhna, Sebastian |
author_sort | Höhna, Sebastian |
collection | PubMed |
description | Large-scale phylogenies provide a valuable source to study background diversification rates and investigate if the rates have changed over time. Unfortunately most large-scale, dated phylogenies are sparsely sampled (fewer than 5% of the described species) and taxon sampling is not uniform. Instead, taxa are frequently sampled to obtain at least one representative per subgroup (e.g. family) and thus to maximize diversity (diversified sampling). So far, such complications have been ignored, potentially biasing the conclusions that have been reached. In this study I derive the likelihood of a birth-death process with non-constant (time-dependent) diversification rates and diversified taxon sampling. Using simulations I test if the true parameters and the sampling method can be recovered when the trees are small or medium sized (fewer than 200 taxa). The results show that the diversification rates can be inferred and the estimates are unbiased for large trees but are biased for small trees (fewer than 50 taxa). Furthermore, model selection by means of Akaike's Information Criterion favors the true model if the true rates differ sufficiently from alternative models (e.g. the birth-death model is recovered if the extinction rate is large and compared to a pure-birth model). Finally, I applied six different diversification rate models – ranging from a constant-rate pure birth process to a decreasing speciation rate birth-death process but excluding any rate shift models – on three large-scale empirical phylogenies (ants, mammals and snakes with respectively 149, 164 and 41 sampled species). All three phylogenies were constructed by diversified taxon sampling, as stated by the authors. However only the snake phylogeny supported diversified taxon sampling. Moreover, a parametric bootstrap test revealed that none of the tested models provided a good fit to the observed data. The model assumptions, such as homogeneous rates across species or no rate shifts, appear to be violated. |
format | Online Article Text |
id | pubmed-3882215 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-38822152014-01-07 Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling Höhna, Sebastian PLoS One Research Article Large-scale phylogenies provide a valuable source to study background diversification rates and investigate if the rates have changed over time. Unfortunately most large-scale, dated phylogenies are sparsely sampled (fewer than 5% of the described species) and taxon sampling is not uniform. Instead, taxa are frequently sampled to obtain at least one representative per subgroup (e.g. family) and thus to maximize diversity (diversified sampling). So far, such complications have been ignored, potentially biasing the conclusions that have been reached. In this study I derive the likelihood of a birth-death process with non-constant (time-dependent) diversification rates and diversified taxon sampling. Using simulations I test if the true parameters and the sampling method can be recovered when the trees are small or medium sized (fewer than 200 taxa). The results show that the diversification rates can be inferred and the estimates are unbiased for large trees but are biased for small trees (fewer than 50 taxa). Furthermore, model selection by means of Akaike's Information Criterion favors the true model if the true rates differ sufficiently from alternative models (e.g. the birth-death model is recovered if the extinction rate is large and compared to a pure-birth model). Finally, I applied six different diversification rate models – ranging from a constant-rate pure birth process to a decreasing speciation rate birth-death process but excluding any rate shift models – on three large-scale empirical phylogenies (ants, mammals and snakes with respectively 149, 164 and 41 sampled species). All three phylogenies were constructed by diversified taxon sampling, as stated by the authors. However only the snake phylogeny supported diversified taxon sampling. Moreover, a parametric bootstrap test revealed that none of the tested models provided a good fit to the observed data. The model assumptions, such as homogeneous rates across species or no rate shifts, appear to be violated. Public Library of Science 2014-01-06 /pmc/articles/PMC3882215/ /pubmed/24400082 http://dx.doi.org/10.1371/journal.pone.0084184 Text en © 2014 Sebastian Höhna http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Höhna, Sebastian Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling |
title | Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling |
title_full | Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling |
title_fullStr | Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling |
title_full_unstemmed | Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling |
title_short | Likelihood Inference of Non-Constant Diversification Rates with Incomplete Taxon Sampling |
title_sort | likelihood inference of non-constant diversification rates with incomplete taxon sampling |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3882215/ https://www.ncbi.nlm.nih.gov/pubmed/24400082 http://dx.doi.org/10.1371/journal.pone.0084184 |
work_keys_str_mv | AT hohnasebastian likelihoodinferenceofnonconstantdiversificationrateswithincompletetaxonsampling |