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opencc-zeroAug 2020View details →

Molecular dating for phylogenies containing a mix of populations and species by using Bayesian and RelTime approaches

Simultaneous molecular dating of population and species divergences is essential in many biological investigations, including phylogeography, phylodynamics, and species delimitation studies. In these investigations, multiple sequence alignments consist of both intra- and inter-species samples (mixed samples). As a result, the phylogenetic trees contain inter-species, inter-population, and within-population divergences. Bayesian relaxed clock methods are often employed in these analyses, but they assume the same tree prior for both inter- and intra-species branching processes and require specification of a clock model for branch rates (independent vs. autocorrelated rates models). We evaluated the impact of a single tree prior onBayesian divergence time estimates by analyzing computer-simulated datasets. We also examined the effectof the assumption of independence of evolutionary rate variation among branches when the branch rates are autocorrelated. Bayesian approach with coalescent tree priors generally produced excellent molecular dates and highest posterior densities with high coverage probabilities. We also evaluated the performance of a non-Bayesian method, RelTime, which does not require the specification of a tree prior or a clock model. RelTime's performance was similar to that of the Bayesian approach, suggesting that it is also suitable to analyze datasets containing both populations and species variation when its computational-efficiency is needed.

opencc-zeroNov 2023View details →

Data from: Bayesian total-evidence dating revisits sloth phylogeny and biogeography: a cautionary tale on morphological clock analyses

Combining morphological and molecular characters through Bayesian total-evidence dating allows inferring the phylogenetic and timescale framework of both extant and fossil taxa, while accounting for the stochasticity and incompleteness of the fossil record. Such an integrative approach is particularly needed when dealing with clades such as sloths (Mammalia: Folivora), for which developmental and biomechanical studies have shown high levels of morphological convergence whereas molecular data can only account for a limited percentage of their total species richness. Here, we propose an alternative hypothesis of sloth evolution that emphasizes the pervasiveness of morphological convergence and the importance of considering the fossil record and an adequate taxon sampling in both phylogenetic and biogeographic inferences. Regardless of different clock models and morphological datasets, the extant sloth Bradypus is consistently recovered as a megatherioid, and Choloepus as a mylodontoid, in agreement with molecular-only analyses. The recently extinct Caribbean sloths (Megalocnoidea) are found to be a monophyletic sister-clade of Megatherioidea, in contrast to previous phylogenetic hypotheses. Our results contradict previous morphological analyses and further support the polyphyly of "Megalonychidae", whose members were found in five different clades. Regardless of taxon sampling and clock models, the Caribbean colonization of sloths is compatible with the exhumation of islands along Aves Ridge and its geological time frame. Overall, our total-evidence analysis illustrates the difficulty of positioning highly incomplete fossils, although a robust phylogenetic framework was recovered by an a posteriori removal of taxa with high percentages of missing characters. Elimination of these taxa improved topological resolution by reducing polytomies and increasing node support. However, it introduced a systematic and geographic bias because most of these incomplete specimens are from northern South America. This is evident in biogeographic reconstructions, which suggest Patagonia as the area of origin of many clades when taxa are underrepresented, but Amazonia and/or Central and Southern Andes when all taxa are included. More generally, our analyses demonstrate the instability of topology and divergence time estimates when using different morphological datasets and clock models, and thus caution against making macroevolutionary inferences when node support is weak or when uncertainties in the fossil record are not considered.

publicDec 2023View details →

Data from: Bayesian total-evidence dating revisits sloth phylogeny and biogeography: a cautionary tale on morphological clock analyses

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publicAug 2020View details →

Molecular dating for phylogenies containing a mix of populations and species by using Bayesian and RelTime approaches

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publicJul 2017View details →

Data from: Detecting ancient co-dispersals and host shifts by double dating of host and parasite phylogenies: application in proctophyllodid feather mites associated with passerine birds

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opencc-zeroSep 2020View details →

A total-evidence dated phylogeny of Echinoidea combining phylogenomic and paleontological data

Phylogenomic and paleontological data constitute complementary resources for unravelling the phylogenetic relationships and divergence times of lineages, yet few studies have attempted to fully integrate them. Several unique properties of echinoids (sea urchins) make them especially useful for such synthetizing approaches, including a remarkable fossil record that can be incorporated into explicit phylogenetic hypotheses. We revisit the phylogeny of crown group Echinoidea using a total-evidence dating approach that combines the largest phylogenomic dataset for the clade, a large-scale morphological matrix with a dense fossil sampling, and a novel compendium of tip and node age constraints. To this end, we develop a novel method for subsampling phylogenomic datasets that selects loci with high phylogenetic signal, low systematic biases and enhanced clock-like behavior. Our results demonstrate that combining different data sources increases topological accuracy and helps resolve conflicts between molecular and morphological data. Notably, we present a new hypothesis for the origin of sand dollars, and restructure the relationships between stem and crown echinoids in a way that implies a long stretch of unidscovered evolutionary history of the crown in the late Paleozoic. Our efforts help bridge the gap between phylogenomics and phylogenetic paleontology, providing a model example of the benefits of combining the two.

opencc-zeroDec 2012View details →

Data from: Phylogeny of salmonids (salmoniformes: Salmonidae) and its molecular dating: analysis of mtDNA data

Phylogenetic relationships among 41 species of salmonid fish and some aspects of their diversification-time history were studied using the GenBank and original mtDNA data. The position of the root of the Salmonidae phylogenetic tree was uncertain. Among the possible variants, the most reasonable seems to be that in which thymallins are grouped into the same clade as coregonins and the lineage of salmonins occupied a basal position relative to this clade. The genera of Salmoninae formed two distinct clades, i.e., (Brachymystax, Hucho) and (Salmo, Parahucho, (Salvelinus, (Parasalmo, Oncorhynchus)). Furthermore, the genera Parasalmo and Oncorhynchus were reciprocally monophyletic. The congruence of Salmonidae phylogenetic trees obtained using different types of phylogenetic markers is discussed. According to Bayesian dating, ancestral lineages of salmonids and their sister esocoids diverged about 106 million years ago. Sometime after, probably 100–70 million years ago, the salmonid-specific whole genome duplication took place. The divergence of salmonid lineages on the genus level occurred much later, within the time interval of 42–20 million years ago. The main wave of the diversification of salmonids at the species level occurred during the last 12 million years. The possible effect of genome duplication on the Salmonidae diversification pattern is discussed.

opencc-zeroDec 2011View details →

Data from: Distribution models and a dated phylogeny for Chilean Oxalis species reveal occupation of new habitats by different lineages, not rapid adaptive radiation

Among the World's most challenging environments for plant life is the Atacama Desert, an arid zone extending over 1300 km and from sea level to 2000/3000 m along the southwestern Andean foothills. Plants there and in the adjacent Mediterranean zone exhibit striking adaptations, and we here use a species-rich such group to address the question whether adaptations arose in parallel, at different times, or simultaneously. Answering this type of question has been a major concern of evolutionary biology over the past few years, with a growing consensus that lineages tend to be conservative in their vegetative traits and niche requirements. Combined nuclear and chloroplast DNA sequences for 112 species of Oxalidales (4900 aligned nucleotides) yielded a fossil-calibrated phylogeny that includes 43 of the 54 species of Oxalis occurring in Chile. Distribution models (SDMs) for these species that included precipitation, temperature, fog and/or vegetation types and the phylogeny were used to reconstruct ancestral habitat preferences, relying on likelihood and Bayesian techniques. Since uneven collecting can reduce the power of SDMs, we used a background sample from 1224 Chilean Oxalis collections to correct models for collecting effort. Models with just 10 of 19 bioclim parameters did as well as more parameter-rich models. Results reveal that the Oxalis flora of Chile consists of seven distant lineages that originated at different times prior to the last Andean uplift pulse and some of which had features pre-adapting them to seasonally arid or xeric conditions. The Mediterranean core zone, south of the Atacama, offered an ecological refuge for insufficiently arid-adapted species and harbors a mix of ancient and young groups. There is no evidence of rapid adaptive radiation.

opencc-zeroFeb 2022View details →

The 'Evil Tribe' spreads across the land: A dated molecular phylogeny provides insight into dispersal, expansion, and biogeographic relationships within one of the largest tribes of the sunflower family (Vernonieae: Compositae)

Premise: With over 1500 species, the globally distributed Vernonieae is one of the most successful members of the Compositae. However, due to its morphological complexity and limited geographic representation in previous studies, subtribal and biogeographic relationships are unclear. Here new DNA sequence data spanning the geographical range of the tribe provides a taxonomically robust time-calibrated phylogeny, an estimation of migration pathways and timing of important biogeographical events and allows inference of environmental factors that have contributed to the success of the Vernonieae worldwide. Methods: Phylogenetic relationships were estimated for 368 taxa representing all Vernonieae subtribes. Molecular clock and ancestral range estimation analyses provide a framework for inference of the tribe's biogeographic history. Results: Relationships among the subtribes were established. We confirmed that the Moquinieae are nested in Vernonieae, determined the correct placement of several problematic taxa, and conducted the first model-based assessment of the biogeographical history of the tribe. The . Vernonieae were estimated to have evolved ~50 Ma ago. Africa was the first center of diversity, from which a single dispersal event established the monophyletic New World lineage. Long-distance dispersal from Africa and Brazil established the tribe on five continents and Oceania. Conclusions: Moquinieae are nested in Vernonieae. The New World lineage is monophyletic, but Old World taxa are not. New subtribal taxonomies are needed. Long-distance dispersal from Africa beginning 45 Ma was key to establishing the tribe's near-global distribution. Migration corridors created by volcanic mountain chains and iron-rich soils in Africa and the Americas promoted radiation and range expansion.

Figure 7 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

Figure 7. Fossil diversity (species) of Evanioidea and Ichneumonoidea during the mid-Mesozoic and Cenozoic (data from

Figure 6 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

Figure 6. Keratodellitha kirin. Holotype IGR.BU-021 (female). A, head in left profile view. B, head in full-face view. C, wings. D, line drawing of wing venation with nomenclature. Scale bars: 0.5 mm.

Figure 4. Keratodellitha anubis. Holotype NIGP174739 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

Figure 4. Keratodellitha anubis. Holotype NIGP174739 (male). A, wing. B, line drawing of wing venation with nomenclature. Scale bars: 0.5 mm.

Figure 5 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

Figure 5. Keratodellitha kirin. Holotype IGR.BU-021 (female). A, habitus in left lateral view. B, habitus in right lateral view. Scale bars: 1 mm.

Figure 2. Keratodellitha basilisci. Holotype NIGP174738 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

Figure 2. Keratodellitha basilisci. Holotype NIGP174738 (female). A, head in full-face view. B, head in right profile view. C, head in dorsal view. D, wings. E, line drawing of wing venation with nomenclature. Scale bars: 0.5 mm.

Figure 3. Keratodellitha anubis. Holotype NIGP174739 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

Figure 3. Keratodellitha anubis. Holotype NIGP174739 (male). A, habitus in right lateral view. B, head in right lateral view. C, head in frontal view. Scale bars: 0.5 mm.

F i g u r e 1. K e r a t o d e l l i t h a b a s i l i s c i. H o l o t y p e NIGP174738 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

F i g u r e 1. K e r a t o d e l l i t h a b a s i l i s c i. H o l o t y p e NIGP174738 (female). A, habitus in right lateral view. B, habitus in left lateral view. Scale bars: 0.5 mm.

Figure 8 in Including fossils in phylogeny: a glimpse into the evolution of the superfamily Evanioidea (Hymenoptera: Apocrita) under tip-dating and the fossilized birth-death process

Figure 8. Bayesian time-calibrated tree of Evanioidea. This tree was recovered from a Mkv+G, fossilized birth–death (FBD) model, with uniform distribution and samplestrat = fossiltip, combining extant and extinct species. Bars at each node represent the 95% highest posterior density in dating estimates. Dotted squares represent crown lineages. Abbreviations: L, Lower; Mid, Middle; Oligo, Oligocene; Paleo, Palaeocene; PP, Pliocene + Pleistocene.