scholarly journals Inferring Species Trees Using Integrative Models of Species Evolution

2018 ◽  
Author(s):  
Huw A. Ogilvie ◽  
Timothy G. Vaughan ◽  
Nicholas J. Matzke ◽  
Graham J. Slater ◽  
Tanja Stadler ◽  
...  

AbstractBayesian methods can be used to accurately estimate species tree topologies, times and other parameters, but only when the models of evolution which are available and utilized sufficiently account for the underlying evolutionary processes. Multispecies coalescent (MSC) models have been shown to accurately account for the evolution of genes within species in the absence of strong gene flow between lineages, and fossilized birth-death (FBD) models have been shown to estimate divergence times from fossil data in good agreement with expert opinion. Until now dating analyses using the MSC have been based on a fixed clock or informally derived node priors instead of the FBD. On the other hand, dating analyses using an FBD process have concatenated all gene sequences and ignored coalescence processes. To address these mirror-image deficiencies in evolutionary models, we have developed an integrative model of evolution which combines both the FBD and MSC models. By applying concatenation and the MSC (without employing the FBD process) to an exemplar data set consisting of molecular sequence data and morphological characters from the dog and fox subfamily Caninae, we show that concatenation causes predictable biases in estimated branch lengths. We then applied concatenation using the FBD process and the combined FBD-MSC model to show that the same biases are still observed when the FBD process is employed. These biases can be avoided by using the FBD-MSC model, which coherently models fossilization and gene evolution, and does not require an a priori substitution rate estimate to calibrate the molecular clock. We have implemented the FBD-MSC in a new version of StarBEAST2, a package developed for the BEAST2 phylogenetic software.


Author(s):  
T.S. Kemp

The vast majority of living and fossil mammals are placentals. Today there are about 4,400 species, which are traditionally organised into 18 Orders, with an extra one if the Pinnipedia are separated from the Carnivora, and a twentieth if the recently extinct Malagasy order Bibymalagasia is recognised as such. There have been many attempts to discover supraordinal groupings from amongst these Orders based on morphological characters, though few proposals have been universally accepted. It is only with the advent of increasingly large sets of molecular sequence data in the last few years that a reasonably robust resolution looks imminent, although these contemporary analyses are remarkably and controversially at odds with the traditional ones. Novacek et al. (1988) summarised the then current situation regarding supraordinal classification of placentals, a time at which morphology was still dominant but molecular data was at the threshold of significance. They accepted a basal group Edentata that combined the Xenarthra of the New World with the Pholidota of the Old, based on a few cranial characters, loss of the anterior teeth, and reduction of the enamel of the remaining ones. This left the rest of the living placentals as a monophyletic group Epitheria, sharing such apparently minor characters as the shape of the stapes bone in the ear. They found very little resolution within the Epitheria, and concluded that there was a polychotomy of no less than nine lineages arranged as a ‘star’ phylogeny. No remnant of the previously recognised taxon Ferungulata, created by Simpson (1945) for the Carnivora plus the ungulate orders Artiodactyla, Perissodactyla, Proboscidea, Hyracoidea, Sirenia, and Tubulidentata remained. On the other hand, three supra ordinal taxa of earlier authors did survive. One was Gregory’s (1910) Archonta, consisting of generally conservative forms and by now composed of the Primates, Dermoptera, Scandentia, and Chiroptera, but excluding the Lipotyphla. The second was Glires, originating with Linnaeus (1758) and widely accepted ever since, for the Rodentia and Lagomorpha; Novacek et al. (1988) tentatively placed the Macroscelidea as the sister-group of the Glires. The third supraordinal taxon recognised was, like Glires, well-established if not universally accepted.



Zootaxa ◽  
2011 ◽  
Vol 2984 (1) ◽  
pp. 67 ◽  
Author(s):  
LEANDRO C. S. ASSIS ◽  
MARCELO R. DE CARVALHO ◽  
QUENTIN D. WHEELER

David Wake and colleagues provided a thought-provoking review of the concept of homoplasy through the integration, within a phylogenetic framework, of genetic and developmental data (Wake et al. 2011). According to them (p. 1032) “Molecular sequence data have greatly increased our ability to identify homoplastic traits.” This is made clear, for example, in their flow chart for homoplasy detection (Figure 2, p. 1034), wherein homoplasy is discovered through the mapping of “traits of interest” onto a phylogram, a practice common in the molecular phylogenetic paradigm. The “mapping” is usually of morphological characters that are employed to support the chosen (molecular) topology, but which, as a consequence, do not themselves contribute to the formation of those topologies (Assis & Carvalho 2010).



Zootaxa ◽  
2019 ◽  
Vol 4642 (1) ◽  
pp. 1-79 ◽  
Author(s):  
JAMES WILDER ORR ◽  
INGRID SPIES ◽  
DUANE E. STEVENSON ◽  
GARY C. LONGO ◽  
YOSHIAKI KAI ◽  
...  

Phylogenetic relationships of snailfishes of the family Liparidae were analyzed on the basis of two sets of molecular sequence data: one from the mitochondrial DNA cytochrome c oxidase subunit one gene (COI) and another from restriction-site associated genome-wide sequences (RADseq). The analysis of COI sequence data from at least 122 species of 18 genera from the Pacific, Atlantic, and Southern oceans resulted in a moderately well-resolved phylogeny among the major clades, albeit with significant polytomy among central clades. Nectoliparis was the sister of all other members of the family, followed by Liparis. Liparis, Careproctus, and Paraliparis were paraphyletic. Liparis was recovered in two closely related clades, with L. fucensis sister of all other liparids except Nectoliparis, and both Careproctus and Paraliparis were each recovered among at least three widely separated clades. The RADseq analysis of 26 species of 11 genera from the eastern North Pacific strongly confirmed the overall results of the COI analysis, with the exception of the paraphyly of Liparis due to the absence of L. fucensis. Our results show that the pelvic disc has been independently lost multiple times and the pectoral-fin girdle has been independently reduced in multiple lineages. 



Data in Brief ◽  
2018 ◽  
Vol 18 ◽  
pp. 1995-1999
Author(s):  
Kyle A. O’Connell ◽  
Eric N. Smith


2014 ◽  
Vol 28 (1) ◽  
pp. 32 ◽  
Author(s):  
Rüdiger Bieler ◽  
Paula M. Mikkelsen ◽  
Timothy M. Collins ◽  
Emily A. Glover ◽  
Vanessa L. González ◽  
...  

To re-evaluate the relationships of the major bivalve lineages, we amassed detailed morpho-anatomical, ultrastructural and molecular sequence data for a targeted selection of exemplar bivalves spanning the phylogenetic diversity of the class. We included molecular data for 103 bivalve species (up to five markers) and also analysed a subset of taxa with four additional nuclear protein-encoding genes. Novel as well as historically employed morphological characters were explored, and we systematically disassembled widely used descriptors such as gill and stomach ‘types’. Phylogenetic analyses, conducted using parsimony direct optimisation and probabilistic methods on static alignments (maximum likelihood and Bayesian inference) of the molecular data, both alone and in combination with morphological characters, offer a robust test of bivalve relationships. A calibrated phylogeny also provided insights into the tempo of bivalve evolution. Finally, an analysis of the informativeness of morphological characters showed that sperm ultrastructure characters are among the best morphological features to diagnose bivalve clades, followed by characters of the shell, including its microstructure. Our study found support for monophyly of most broadly recognised higher bivalve taxa, although support was not uniform for Protobranchia. However, monophyly of the bivalves with protobranchiate gills was the best-supported hypothesis with incremental morphological and/or molecular sequence data. Autobranchia, Pteriomorphia, Heteroconchia, Palaeoheterodonta, Archiheterodonta, Euheterodonta, Anomalodesmata and Imparidentia new clade ( = Euheterodonta excluding Anomalodesmata) were recovered across analyses, irrespective of data treatment or analytical framework. Another clade supported by our analyses but not formally recognised in the literature includes Palaeoheterodonta and Archiheterodonta, which emerged under multiple analytical conditions. The origin and diversification of each of these major clades is Cambrian or Ordovician, except for Archiheterodonta, which diverged from Palaeoheterodonta during the Cambrian, but diversified during the Mesozoic. Although the radiation of some lineages was shifted towards the Palaeozoic (Pteriomorphia, Anomalodesmata), or presented a gap between origin and diversification (Archiheterodonta, Unionida), Imparidentia showed steady diversification through the Palaeozoic and Mesozoic. Finally, a classification system with six major monophyletic lineages is proposed to comprise modern Bivalvia: Protobranchia, Pteriomorphia, Palaeoheterodonta, Archiheterodonta, Anomalodesmata and Imparidentia.



Zootaxa ◽  
2010 ◽  
Vol 2553 (1) ◽  
pp. 35 ◽  
Author(s):  
MARJOLAINE GIROUX ◽  
TERRY A. WHEELER

Sarcophaga (Bulbostyla) subgen. nov. is described as a new subgenus of Sarcophaga Meigen to accommodate some species previously assigned to the subgenus S. (Neobellieria) Blanchard. Sarcophaga (Bulbostyla) contains nine species: S. airosalis sp. nov., S. cadyi sp. nov. (type species), S. cuautla sp. nov., S. fattigina sp. nov., S. ironalis sp. nov., S. semimarginalis Hall, S. sternalis (Reinhard), S. subdiscalis Aldrich and S. yorkii Parker. All species are described and illustrated and a key to the species is provided. The species within the subgenus are morphologically uniform externally and are distinguished mostly on male genitalic characters. Phylogenetic relationships within Bulbostyla are unresolved based on morphological characters and will require consideration of additional characters, such as molecular sequence data. The genus-group taxon Robackina Lopes is removed from synonymy with the subgenus Sarcophaga (Neobellieria) and reinstated as a valid subgenus of Sarcophaga (stat. nov.) to accommodate the single New World species Sarcophaga triplasia Wulp. A lectotype is designated for S. triplasia. The subgenus and species are redescribed and illustrated.



2008 ◽  
Vol 54 (2) ◽  
pp. 223-238 ◽  
Author(s):  
Henrik Glenner ◽  
Philip Francis Thomsen ◽  
Alexey V. Rybakov ◽  
Bella S. Galil ◽  
Jens T. Hoeg

Within parasitic barnacles of the family Sacculinidae, the genus Heterosaccus is the third largest, with 12 species infesting various brachyuran hosts throughout the world. As part of an effort to reconstruct rhizocephalan phylogeny we performed an analysis of four species of Heterosaccus and of selected sacculinid and non-sacculinid rhizocephalans. We used both molecular sequence data (16s rDNA and 18s rDNA) and morphological characters from an SEM analysis of the cypris larvae. Using Bayesian methods we obtained a highly supported tree in which the four species of Heterosaccus form a monophylum, whereas both the genus Sacculina and the family Sacculinidae are polyphyletic. The sistergroup to Heterosaccus is a clade consisting of the sacculinids Loxothylacus panopaei and the "classical" rhizocephalan Sacculina carcini. The molecular results found support in cypris morphology, where we identified two distinct synapomorphies for Heterosaccus, both present in male cyprids only: A large flap extending posteriorly from the third antennular segment, and the male-specific aesthetasc on the third segment being reduced to a rudiment or lacking completely. Female cyprids didn't show generic level apomorphies but resembled those of other sacculinid species. No morphological synapomorphies were identified between Heterosaccus, L. panopaei and S. carcini. While larval characters proved to be informative, we conclude that future studies on rhizocephalan taxonomy must rely primarily on molecular data, both to provide an overall phylogenetic framework and to assure an accurate identification of species for biogeographical and other biological purposes.



Zootaxa ◽  
2010 ◽  
Vol 2665 (1) ◽  
pp. 51 ◽  
Author(s):  
ELENA K. KUPRIYANOVA ◽  
EIJIROH NISHI

A collection of Serpulidae (Annelida, Polychaeta) from the Patton-Murray Seamounts, Gulf of Alaska, USA contained three species Apomatus voightae n. sp., Bathyvermilia eliasoni n. comb., and Hyalopomatus biformis (Hartman, 1960). Apomatus voightae n. sp. differed from all other Apomatus spp. and from all known serpulid species by very unusual flat and ribbon-like branchial radioles as well by details of chaetal structure. Vermiliopsis eliasoni Zibrowius (1970) previously known from Atlantic and Mediterranean, was transferred to the genus Bathyvermilia Zibrowius, 1973. Hyalopomatus biformis is a deep-sea species distributed in the north-eastern Pacific from Alaska to California, USA. All serpulids were described in detail and their chaetal structure elucidated with the help of scanning electron microscopy. Molecular sequence data (18S rDNA) were aligned to a recently published serpulid data set and maximum parsimony analysis was performed to examine the phylogenetic position of the species and confirm their identification. Hyalopomatus biformis formed a sister group with Laminatubus alvini, Apomatus voightae n. sp. formed a sister group with Apomatus globifer, and Bathyvermilia eliasoni formed a weakly supported polytomy with Chitinopoma serrula, Protula tubularia and Apomatus spp. We briefly discussed biogeographic affinities of the serpulids from the PattonMurray Seamounts in the light of seamount ecology and biogeography.



2017 ◽  
Author(s):  
Charles S. P. Foster ◽  
Simon Y. W. Ho

AbstractEvolutionary timescales can be inferred from molecular sequence data using a Bayesian phylogenetic approach. In these methods, the molecular clock is often calibrated using fossil data. The uncertainty in these fossil calibrations is important because it determines the limiting posterior distribution for divergence-time estimates as the sequence length tends to infinity. Here we investigate how the accuracy and precision of Bayesian divergence-time estimates improve with the increased clock-partitioning of genome-scale data into clock-subsets. We focus on a data set comprising plastome-scale sequences of 52 angiosperm taxa. There was little difference among the Bayesian date estimates whether we chose clock-subsets based on patterns of among-lineage rate heterogeneity or relative rates across genes, or by random assignment. Increasing the degree of clock-partitioning usually led to an improvement in the precision of divergence-time estimates, but this increase was asymptotic to a limit presumably imposed by fossil calibrations. Our clock-partitioning approaches yielded highly precise age estimates for several key nodes in the angiosperm phylogeny. For example, when partitioning the data into 20 clock-subsets based on patterns of among-lineage rate heterogeneity, we inferred crown angiosperms to have arisen 198–178 Ma. This demonstrates that judicious clock-partitioning can improve the precision of molecular dating based on phylogenomic data, but the meaning of this increased precision should be considered critically.



2018 ◽  
Vol 50 (3) ◽  
pp. 299-312 ◽  
Author(s):  
Steven D. LEAVITT ◽  
Paul M. KIRIKA ◽  
Guillermo AMO DE PAZ ◽  
Jen-Pan HUANG ◽  
Jae-Seoun HUR ◽  
...  

AbstractSpecies richness is not evenly distributed across the tree of life and a limited number of lineages comprise an extraordinarily large number of species. In lichen-forming fungi, only two genera are known to be ‘ultradiverse’ (>500 species), with the most diverse genus, Xanthoparmelia, consisting of c. 820 species. While Australia and South Africa are known as current centres of diversity for Xanthoparmelia, it is not well known when and where this massive diversity arose. To better understand the geographical and temporal context of diversification in this diverse genus, we sampled 191 Xanthoparmelia specimens representing c. 124 species/species-level lineages from populations worldwide. From these specimens, we generated a multi-locus sequence data set using Sanger and high-throughput sequencing to reconstruct evolutionary relationships in Xanthoparmelia, estimate divergence times and reconstruct biogeographical histories in a maximum likelihood and Bayesian framework. This study corroborated the phylogenetic placement of several morphologically or chemically diverse taxa within Xanthoparmelia, such as Almbornia, Chondropsis, Karoowia, Namakwa, Neofuscelia, Omphalodiella, Paraparmelia, Placoparmelia and Xanthomaculina, in addition to improved phylogenetic resolution and reconstruction of previously unsampled lineages within Xanthoparmelia. Our data indicate that Xanthoparmelia most likely originated in Africa during the early Miocene, coinciding with global aridification and development of open habitats. Reconstructed biogeographical histories of Xanthoparmelia reveal diversification restricted to continents with infrequent intercontinental exchange by long-distance dispersal. While likely mechanisms by which Xanthoparmelia obtained strikingly high levels of species richness in Australia and South Africa remain uncertain, this study provides a framework for ongoing research into diverse lineages of lichen-forming fungi. Finally, our study highlights a novel approach for generating locus-specific molecular sequence data sets from high throughput metagenomic reads.



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