{"title":"Expectation-Maximization enables Phylogenetic Dating under a Categorical Rate Model.","authors":"Uyen Mai, Eduardo Charvel, Siavash Mirarab","doi":"10.1093/sysbio/syae034","DOIUrl":"10.1093/sysbio/syae034","url":null,"abstract":"<p><p>Dating phylogenetic trees to obtain branch lengths in time units is essential for many downstream applications but has remained challenging. Dating requires inferring substitution rates that can change across the tree. While we can assume to have information about a small subset of nodes from the fossil record or sampling times (for fast-evolving organisms), inferring the ages of the other nodes essentially requires extrapolation and interpolation. Assuming a distribution of branch rates, we can formulate dating as a constrained maximum likelihood (ML) estimation problem. While ML dating methods exist, their accuracy degrades in the face of model misspecification, where the assumed parametric statistical distribution of branch rates vastly differs from the true distribution. Notably, most existing methods assume rigid, often unimodal, branch rate distributions. A second challenge is that the likelihood function involves an integral over the continuous domain of the rates, often leading to difficult non-convex optimization problems. To tackle both challenges, we propose a new method called Molecular Dating using Categorical-models (MD-Cat). MD-Cat uses a categorical model of rates inspired by non-parametric statistics and can approximate a large family of models by discretizing the rate distribution into k categories. Under this model, we can use the Expectation-Maximization algorithm to co-estimate rate categories and branch lengths in time units. Our model has fewer assumptions about the true distribution of branch rates than parametric models such as Gamma or LogNormal distribution. Our results on two simulated and real datasets of Angiosperms and HIV and a wide selection of rate distributions show that MD-Cat is often more accurate than the alternatives, especially on datasets with exponential or multimodal rate distributions.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":"823-838"},"PeriodicalIF":6.1,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11524793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141545291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thore Koppetsch, Milan Malinsky, Michael Matschiner
{"title":"Towards Reliable Detection of Introgression in the Presence of Among-Species Rate Variation.","authors":"Thore Koppetsch, Milan Malinsky, Michael Matschiner","doi":"10.1093/sysbio/syae028","DOIUrl":"10.1093/sysbio/syae028","url":null,"abstract":"<p><p>The role of interspecific hybridization has recently seen increasing attention, especially in the context of diversification dynamics. Genomic research has now made it abundantly clear that both hybridization and introgression-the exchange of genetic material through hybridization and backcrossing-are far more common than previously thought. Besides cases of ongoing or recent genetic exchange between taxa, an increasing number of studies report \"ancient introgression\"- referring to results of hybridization that took place in the distant past. However, it is not clear whether commonly used methods for the detection of introgression are applicable to such old systems, given that most of these methods were originally developed for analyses at the level of populations and recently diverged species, affected by recent or ongoing genetic exchange. In particular, the assumption of constant evolutionary rates, which is implicit in many commonly used approaches, is more likely to be violated as evolutionary divergence increases. To test the limitations of introgression detection methods when being applied to old systems, we simulated thousands of genomic datasets under a wide range of settings, with varying degrees of among-species rate variation and introgression. Using these simulated datasets, we showed that some commonly applied statistical methods, including the D-statistic and certain tests based on sets of local phylogenetic trees, can produce false-positive signals of introgression between divergent taxa that have different rates of evolution. These misleading signals are caused by the presence of homoplasies occurring at different rates in different lineages. To distinguish between the patterns caused by rate variation and genuine introgression, we developed a new test that is based on the expected clustering of introgressed sites along the genome and implemented this test in the program Dsuite.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":"769-788"},"PeriodicalIF":6.1,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141443357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brooke Bodensteiner, Edward D Burress, Martha M Muñoz
{"title":"Adaptive Radiation Without Independent Stages of Trait Evolution in a Group of Caribbean Anoles.","authors":"Brooke Bodensteiner, Edward D Burress, Martha M Muñoz","doi":"10.1093/sysbio/syae041","DOIUrl":"10.1093/sysbio/syae041","url":null,"abstract":"<p><p>Adaptive radiation involves diversification along multiple trait axes, producing phenotypically diverse, species-rich lineages. Theory generally predicts that multi-trait evolution occurs via a \"stages\" model, with some traits saturating early in a lineage's history, and others diversifying later. Despite its multidimensional nature, however, we know surprisingly little about how different suites of traits evolve during adaptive radiation. Here, we investigated the rate, pattern, and timing of morphological and physiological evolution in the anole lizard adaptive radiation from the Caribbean island of Hispaniola. Rates and patterns of morphological and physiological diversity are largely unaligned, corresponding to independent selective pressures associated with structural and thermal niches. Cold tolerance evolution reflects parapatric divergence across elevation, rather than niche partitioning within communities. Heat tolerance evolution and the preferred temperature evolve more slowly than cold tolerance, reflecting behavioral buffering, particularly in edge-habitat species (a pattern associated with the Bogert effect). In contrast to the nearby island of Puerto Rico, closely related anoles on Hispaniola do not sympatrically partition thermal niche space. Instead, allopatric and parapatric separation across biogeographic and environmental boundaries serves to keep morphologically similar close relatives apart. The phenotypic diversity of this island's adaptive radiation accumulated largely as a by-product of time, with surprisingly few exceptional pulses of trait evolution. A better understanding of the processes that guide multidimensional trait evolution (and nuance therein) will prove key in determining whether the stages model should be considered a common theme of adaptive radiation.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":"743-757"},"PeriodicalIF":6.1,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141879499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R Alexander Pyron, Kyle A O'Connell, Edward A Myers, David A Beamer, Hector Baños
{"title":"Complex Hybridization in a Clade of Polytypic Salamanders (Plethodontidae: Desmognathus) Uncovered by Estimating Higher-Level Phylogenetic Networks.","authors":"R Alexander Pyron, Kyle A O'Connell, Edward A Myers, David A Beamer, Hector Baños","doi":"10.1093/sysbio/syae060","DOIUrl":"https://doi.org/10.1093/sysbio/syae060","url":null,"abstract":"<p><p>Reticulation between incipient lineages is a common feature of diversification. We examine these phenomena in the Pisgah clade of Desmognathus salamanders from the southern Appalachian Mountains of the eastern United States. The group contains four to seven species exhibiting two discrete phenotypes, aquatic \"shovel-nosed\" and semi-aquatic \"black-bellied\" forms. These ecomorphologies are ancient and have apparently been transmitted repeatedly between lineages through introgression. Geographically proximate populations of both phenotypes exhibit admixture, and at least two black-bellied lineages have been produced via reticulations between shovel-nosed parentals, suggesting potential hybrid speciation dynamics. However, computational constraints currently limit our ability to reconstruct network radiations from gene-tree data. Available methods are limited to level-1 networks wherein reticulations do not share edges, and higher-level networks may be non-identifiable in many cases. We present a heuristic approach to recover information from higher-level networks across a range of potentially identifiable empirical scenarios, supported by theory and simulation. When extrinsic information indicates the location and direction of reticulations, our method can successfully estimate a reduced possible set of non-level-1 networks. Phylogenomic data support a single backbone topology with up to five overlapping hybrid edges in the Pisgah clade. These results suggest an unusual mechanism of ecomorphological hybrid speciation, wherein a binary threshold trait causes some hybrid populations to shift between microhabitat niches, promoting ecological divergence between sympatric hybrids and parentals. This contrasts with other well-known systems in which hybrids exhibit intermediate, novel, or transgressive phenotypes. The genetic basis of these phenotypes is unclear and further data are needed to clarify the evolutionary basis of morphological changes with ecological consequences.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142523144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlos A Maya-Lastra, Patrick W Sweeney, Deren A R Eaton, Vania Torrez, Carla Maldonado, Malu I Ore-Rengifo, Mónica Arakaki, Michael J Donoghue, Erika J Edwards
{"title":"Caught in the Act: Incipient Speciation at the Southern Limit of Viburnum in the Central Andes.","authors":"Carlos A Maya-Lastra, Patrick W Sweeney, Deren A R Eaton, Vania Torrez, Carla Maldonado, Malu I Ore-Rengifo, Mónica Arakaki, Michael J Donoghue, Erika J Edwards","doi":"10.1093/sysbio/syae023","DOIUrl":"10.1093/sysbio/syae023","url":null,"abstract":"<p><p>A fundamental objective of evolutionary biology is to understand the origin of independently evolving species. Phylogenetic studies of species radiations rarely are able to document ongoing speciation; instead, modes of speciation, entailing geographic separation and/or ecological differentiation, are posited retrospectively. The Oreinotinus clade of Viburnum has radiated recently from north to south through the cloud forests of Mexico and Central America to the Central Andes. Our analyses support a hypothesis of incipient speciation in Oreinotinus at the southern edge of its geographic range, from central Peru to northern Argentina. Although several species and infraspecific taxa have been recognized in this area, multiple lines of evidence and analytical approaches (including analyses of phylogenetic relationships, genetic structure, leaf morphology, and climatic envelopes) favor the recognition of just a single species, V. seemenii. We show that what has previously been recognized as V. seemenii f. minor has recently occupied the drier Tucuman-Bolivian forest region from Samaipata in Bolivia to Salta in northern Argentina. Plants in these populations form a well-supported clade with a distinctive genetic signature and they have evolved smaller, narrower leaves. We interpret this as the beginning of a within-species divergence process that has elsewhere in the neotropics resulted repeatedly in Viburnum species with a particular set of leaf ecomorphs. Specifically, the southern populations are in the process of evolving the small, glabrous, and entire leaf ecomorph that has evolved in four other montane areas of endemism. As predicted based on our studies of leaf ecomorphs in Chiapas, Mexico, these southern populations experience generally drier conditions, with large diurnal temperature fluctuations. In a central portion of the range of V. seemenii, characterized by wetter climatic conditions, we also document what may be the initial differentiation of the leaf ecomorph with larger, pubescent, and toothy leaves. The emergence of these ecomorphs thus appears to be driven by adaptation to subtly different climatic conditions in separate geographic regions, as opposed to parapatric differentiation along elevational gradients as suggested by Viburnum species distributions in other parts of the neotropics.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":"629-643"},"PeriodicalIF":6.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141238062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giorgio Bianchini, Martin Hagemann, Patricia Sánchez-Baracaldo
{"title":"Stochastic Character Mapping, Bayesian Model Selection, and Biosynthetic Pathways Shed New Light on the Evolution of Habitat Preference in Cyanobacteria.","authors":"Giorgio Bianchini, Martin Hagemann, Patricia Sánchez-Baracaldo","doi":"10.1093/sysbio/syae025","DOIUrl":"10.1093/sysbio/syae025","url":null,"abstract":"<p><p>Cyanobacteria are the only prokaryotes to have evolved oxygenic photosynthesis paving the way for complex life. Studying the evolution and ecological niche of cyanobacteria and their ancestors is crucial for understanding the intricate dynamics of biosphere evolution. These organisms frequently deal with environmental stressors such as salinity and drought, and they employ compatible solutes as a mechanism to cope with these challenges. Compatible solutes are small molecules that help maintain cellular osmotic balance in high-salinity environments, such as marine waters. Their production plays a crucial role in salt tolerance, which, in turn, influences habitat preference. Among the 5 known compatible solutes produced by cyanobacteria (sucrose, trehalose, glucosylglycerol, glucosylglycerate, and glycine betaine), their synthesis varies between individual strains. In this study, we work in a Bayesian stochastic mapping framework, integrating multiple sources of information about compatible solute biosynthesis in order to predict the ancestral habitat preference of Cyanobacteria. Through extensive model selection analyses and statistical tests for correlation, we identify glucosylglycerol and glucosylglycerate as the most significantly correlated with habitat preference, while trehalose exhibits the weakest correlation. Additionally, glucosylglycerol, glucosylglycerate, and glycine betaine show high loss/gain rate ratios, indicating their potential role in adaptability, while sucrose and trehalose are less likely to be lost due to their additional cellular functions. Contrary to previous findings, our analyses predict that the last common ancestor of Cyanobacteria (living at around 3180 Ma) had a 97% probability of a high salinity habitat preference and was likely able to synthesize glucosylglycerol and glucosylglycerate. Nevertheless, cyanobacteria likely colonized low-salinity environments shortly after their origin, with an 89% probability of the first cyanobacterium with low-salinity habitat preference arising prior to the Great Oxygenation Event (2460 Ma). Stochastic mapping analyses provide evidence of cyanobacteria inhabiting early marine habitats, aiding in the interpretation of the geological record. Our age estimate of ~2590 Ma for the divergence of 2 major cyanobacterial clades (Macro- and Microcyanobacteria) suggests that these were likely significant contributors to primary productivity in marine habitats in the lead-up to the Great Oxygenation Event, and thus played a pivotal role in triggering the sudden increase in atmospheric oxygen.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":"644-665"},"PeriodicalIF":6.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11505929/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141459410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lena Collienne, Mary Barker, Marc A Suchard, Frederick A Matsen IV
{"title":"Phylogenetic tree instability after taxon addition: empirical frequency, predictability, and consequences for online inference","authors":"Lena Collienne, Mary Barker, Marc A Suchard, Frederick A Matsen IV","doi":"10.1093/sysbio/syae059","DOIUrl":"https://doi.org/10.1093/sysbio/syae059","url":null,"abstract":"Online phylogenetic inference methods add sequentially arriving sequences to an inferred phylogeny without the need to recompute the entire tree from scratch. Some online method implementations exist already, but there remains concern that additional sequences may change the topological relationship among the original set of taxa. We call such a change in tree topology a lack of stability for the inferred tree. In this paper, we analyze the stability of single taxon addition in a Maximum Likelihood framework across 1, 000 empirical datasets. We find that instability occurs in almost 90% of our examples, although observed topological differences do not always reach significance under the AU-test. Changes in tree topology after addition of a taxon rarely occur close to its attachment location, and are more frequently observed in more distant tree locations carrying low bootstrap support. To investigate whether instability is predictable, we hypothesize sources of instability and design summary statistics addressing these hypotheses. Using these summary statistics as input features for machine learning under random forests, we are able to predict instability and can identify the most influential features. In summary, it does not appear that a strict insertion-only online inference method will deliver globally optimal trees, although relaxing insertion strictness by allowing for a small number of final tree rearrangements or accepting slightly suboptimal solutions appears feasible.","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":"31 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142490398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Phylogenomic Backbone for Acoelomorpha Inferred from Transcriptomic Data","authors":"Samuel Abalde, Ulf Jondelius","doi":"10.1093/sysbio/syae057","DOIUrl":"https://doi.org/10.1093/sysbio/syae057","url":null,"abstract":"Xenacoelomorpha are mostly microscopic, morphologically simple worms, lacking many structures typical of other bilaterians. Xenacoelomorphs –which include three main groups: Acoela, Nemertodermatida, and Xenoturbella– have been proposed to be an early diverging Bilateria, sister to protostomes and deuterostomes, but other phylogenomic analyses have recovered this clade nested within the deuterostomes, as sister to Ambulacraria. The position of Xenacoelomorpha within the metazoan tree has understandably attracted a lot of attention, overshadowing the study of phylogenetic relationships within this group. Given that Xenoturbella includes only six species whose relationships are well understood, we decided to focus on the most speciose Acoelomorpha (Acoela + Nemertodermatida). Here, we have sequenced 29 transcriptomes, doubling the number of sequenced species, to infer a backbone tree for Acoelomorpha based on genomic data. The recovered topology is mostly congruent with previous studies. The most important difference is the recovery of Paratomella as the first off-shoot within Acoela, dramatically changing the reconstruction of the ancestral acoel. Besides, we have detected incongruence between the gene trees and the species tree, likely linked to incomplete lineage sorting, and some signal of introgression between the families Dakuidae and Mecynostomidae, which hampers inferring the correct placement of this family and, particularly, of the genus Notocelis. We have also used this dataset to infer for the first time diversification times within Acoelomorpha, which coincide with known bilaterian diversification and extinction events. Given the importance of morphological data in acoelomorph phylogenetics, we tested several partitions and models. Although morphological data failed to recover a robust phylogeny, phylogenetic placement has proven to be a suitable alternative when a reference phylogeny is available.","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":"97 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142489582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
George P Tiley, Andrew A Crowl, Paul S Manos, Emily B Sessa, Claudia Solís-Lemus, Anne D Yoder, J Gordon Burleigh
{"title":"Benefits and Limits of Phasing Alleles for Network Inference of Allopolyploid Complexes.","authors":"George P Tiley, Andrew A Crowl, Paul S Manos, Emily B Sessa, Claudia Solís-Lemus, Anne D Yoder, J Gordon Burleigh","doi":"10.1093/sysbio/syae024","DOIUrl":"10.1093/sysbio/syae024","url":null,"abstract":"<p><p>Accurately reconstructing the reticulate histories of polyploids remains a central challenge for understanding plant evolution. Although phylogenetic networks can provide insights into relationships among polyploid lineages, inferring networks may be hindered by the complexities of homology determination in polyploid taxa. We use simulations to show that phasing alleles from allopolyploid individuals can improve phylogenetic network inference under the multispecies coalescent by obtaining the true network with fewer loci compared with haplotype consensus sequences or sequences with heterozygous bases represented as ambiguity codes. Phased allelic data can also improve divergence time estimates for networks, which is helpful for evaluating allopolyploid speciation hypotheses and proposing mechanisms of speciation. To achieve these outcomes in empirical data, we present a novel pipeline that leverages a recently developed phasing algorithm to reliably phase alleles from polyploids. This pipeline is especially appropriate for target enrichment data, where the depth of coverage is typically high enough to phase entire loci. We provide an empirical example in the North American Dryopteris fern complex that demonstrates insights from phased data as well as the challenges of network inference. We establish that our pipeline (PATÉ: Phased Alleles from Target Enrichment data) is capable of recovering a high proportion of phased loci from both diploids and polyploids. These data may improve network estimates compared with using haplotype consensus assemblies by accurately inferring the direction of gene flow, but statistical nonidentifiability of phylogenetic networks poses a barrier to inferring the evolutionary history of reticulate complexes.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":"666-682"},"PeriodicalIF":6.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140908806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sequential Bayesian Phylogenetic Inference.","authors":"Sebastian Höhna, Allison Y Hsiang","doi":"10.1093/sysbio/syae020","DOIUrl":"10.1093/sysbio/syae020","url":null,"abstract":"<p><p>The ideal approach to Bayesian phylogenetic inference is to estimate all parameters of interest jointly in a single hierarchical model. However, this is often not feasible in practice due to the high computational cost. Instead, phylogenetic pipelines generally consist of sequential analyses, whereby a single point estimate from a given analysis is used as input for the next analysis (e.g., a single multiple sequence alignment is used to estimate a gene tree). In this framework, uncertainty is not propagated from step to step, which can lead to inaccurate or spuriously confident results. Here, we formally develop and test a sequential inference approach for Bayesian phylogenetic inference, which uses importance sampling to generate observations for the next step of an analysis pipeline from the posterior distribution produced in the previous step. Our sequential inference approach presented here not only accounts for uncertainty between analysis steps but also allows for greater flexibility in software choice (and hence model availability) and can be computationally more efficient than the traditional joint inference approach when multiple models are being tested. We show that our sequential inference approach is identical in practice to the joint inference approach only if sufficient information in the data is present (a narrow posterior distribution) and/or sufficiently many important samples are used. Conversely, we show that the common practice of using a single point estimate can be biased, for example, a single phylogeny estimate can transform an unrooted phylogeny into a time-calibrated phylogeny. We demonstrate the theory of sequential Bayesian inference using both a toy example and an empirical case study of divergence-time estimation in insects using a relaxed clock model from transcriptome data. In the empirical example, we estimate 3 posterior distributions of branch lengths from the same data (DNA character matrix with a GTR+Γ+I substitution model, an amino acid data matrix with empirical substitution models, and an amino acid data matrix with the PhyloBayes CAT-GTR model). Finally, we apply 3 different node-calibration strategies and show that divergence time estimates are affected by both the data source and underlying substitution process to estimate branch lengths as well as the node-calibration strategies. Thus, our new sequential Bayesian phylogenetic inference provides the opportunity to efficiently test different approaches for divergence time estimation, including branch-length estimation from other software.</p>","PeriodicalId":22120,"journal":{"name":"Systematic Biology","volume":" ","pages":"704-721"},"PeriodicalIF":6.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141071866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}