scholarly journals The evolutionary history of holometabolous insects inferred from transcriptome-based phylogeny and comprehensive morphological data

2014 ◽  
Vol 14 (1) ◽  
pp. 52 ◽  
Author(s):  
Ralph S Peters ◽  
Karen Meusemann ◽  
Malte Petersen ◽  
Christoph Mayer ◽  
Jeanne Wilbrandt ◽  
...  
2021 ◽  
Author(s):  
Ixchel Gonzalez-Ramirez ◽  
Sergio RS Cevallos-Ferriz ◽  
Carl Rothfels

Premise of study: El Chango is a recently discovered quarry that contains extremely well preserved fossils. The Cenomanian age of the locality corresponds to a time when the global flora was transitioning from gymnosperm- to angiosperm-dominated, yet conifers predominate in this locality. These fossils thus provide a rare opportunity to understand the replacement of conifers by angiosperms as the dominant group of plants. Methods: We collected material from El Chango in annual expeditions (2010 to 2014). We selected the three most abundant and best preserved conifer morphotypes and conducted a total-evidence (i.e., including molecular and morphological data) phylogenetic analysis of a sample of 72 extant conifer species plus the three fossils. We use these results to inform our taxonomic decisions. Results: We obtained four equally most-parsimonious trees (consistency index = 44.1%, retention index = 78.8%). Despite ambiguous relationships among some extant taxa, the three fossil conifers had the same phylogenetic position in all four most parsimonious trees; we describe these species as new: Sequoiadendron helicalancifolium sp. nov. (Cupressaceae), and Microcachrys rhomboidea sp. nov. and Dacrydium bifoliosus sp. nov (Podocarpaceae). The ecosystem is interpreted as a coastal humid mixed forest. Conclusions: Our findings contribute to the understanding of Cenomanian equatorialregions, and support the hypothesis of a geographically and ecologically structured rise of angiosperms, with conifers remaining dominant in brackish-water and angiosperms becoming dominant in freshwater-ecosystems. These fossils fill in gaps in the evolutionary history of lineages like Microcachrys, which we demonstrate occurred in the Northern hemisphere before becoming restricted to its current range (Tasmania).


2021 ◽  
Vol 118 (10) ◽  
pp. e2019865118
Author(s):  
Yilun Yu ◽  
Chi Zhang ◽  
Xing Xu

Reconstructing the history of biodiversity has been hindered by often-separate analyses of stem and crown groups of the clades in question that are not easily understood within the same unified evolutionary framework. Here, we investigate the evolutionary history of birds by analyzing three supertrees that combine published phylogenies of both stem and crown birds. Our analyses reveal three distinct large-scale increases in the diversification rate across bird evolutionary history. The first increase, which began between 160 and 170 Ma and reached its peak between 130 and 135 Ma, corresponds to an accelerated morphological evolutionary rate associated with the locomotory systems among early stem birds. This radiation resulted in morphospace occupation that is larger and different from their close dinosaurian relatives, demonstrating the occurrence of a radiation among early stem birds. The second increase, which started ∼90 Ma and reached its peak between 65 and 55 Ma, is associated with rapid evolution of the cranial skeleton among early crown birds, driven differently from the first radiation. The third increase, which occurred after ∼40 to 45 Ma, has yet to be supported by quantitative morphological data but gains some support from the fossil record. Our analyses indicate that the bird biodiversity evolution was influenced mainly by long-term climatic changes and also by major paleobiological events such as the Cretaceous–Paleogene (K–Pg) extinction.


2015 ◽  
Author(s):  
Gabriel S Ferreira ◽  
Juliana Sterli ◽  
Mario Bronzati Filho ◽  
Max C Langer

Background. Most studies on pleurodiran turtles are about the behavior and/or feeding habits analyzes, description of new taxa or specimens (both extinct and extant), or phylogenetic analyzes of one of its subclades with extant taxa: Chelidae, Pelomedusidae or Podocnemididae. With the exception of some molecular phylogenies, there are no phylogenetic analyses of extant and extinct representatives of Pleurodira including all of its lineages. A broader understanding of the evolutionary history of Pleurodira requires a phylogenetic hypothesis based on more extensive taxonomic and character samplings.Methods. We constructed a taxon-character matrix including 227 morphological characters and 87 taxa from all the Pleurodira lineages, plus one stem Pan-Pleurodira, Notoemys laticentralis, and one stem-Testudinata, Proganochelys quenstedti, as outgroups. The resulting matrix was analyzed using parsimony, Tree Bisection and Reconnection (TBR) algorithms, with 5000 replicates, and a hold of 20. The obtained strict consensus tree was used as the basis of a diversification analysis using topology-based methods. A nestedgrowing tree approach was employed to create a corresponding tree for different intervals of the geological history of the group. Six distinct time bins were created for periods in which members of Pleurodira occur: Early Cretaceous, Late Cretaceous, Paleocene, Eocene, Miocene, and Recent. Results. All main pleurodiran clades were recovered in the strict consensus tree, but with some changes in their relationship compared to previous analyses, e.g. the inclusiveness of both Pelomedusoides and Bothremydidae. The diversification analysis shows that, after the establishment of the two major lineages (i.e. Chelidae and Pelomedusoides) in the Early Cretaceous, these subgroups diversified in distinct rates along their evolutionary history. Two main diversification shifts were identified: one at the early evolution of Podocnemoidea, during the Late Cretaceous, and another during the Miocene, deep nested in the Podocnemididae clade. Discussion. The resulting strict consensus tree is the largest exclusive phylogenetic hypothesis for Pleurodira, including both extant and extinct taxa. Based on morphological data, it allows more inclusive inferences on the general morphological and diversification patterns of the group. The diversification pulses analysis suggests variation on the rates of diversification on the different pleurodiran clades. The first shift detected is related to the great radiation of Bothremydidae and Podocnemoidae in the Late Cretaceous; the second shift, detected in the Miocene, is related to a diversification within the Stereogenyina, a Podocnemididae clade. Ongoing analysis will determine which factors could enforce those different diversification rates in the evolution of Pleurodira.


2016 ◽  
Author(s):  
Karen Luna-Ramirez ◽  
Adam D Miller ◽  
Gordana Rašić

Background. Australian scorpions have received far less attention from researchers than their overseas counterparts. Here we provide the first insight into the molecular variation and evolutionary history of the endemic Australian scorpion Urodacus yaschenkoi. Also known as the inland robust scorpion, it is widely distributed throughout arid zones of the continent and is emerging as a model organism in biomedical research due to the chemical nature of its venom. Methods. We employed Bayesian Inference (BI) methods for the phylogenetic reconstructions and divergence dating among lineages, using unique haplotype sequences from two mitochondrial loci (COXI, 16S) and one nuclear locus (28S). We also implemented two DNA taxonomy approaches (GMYC and PTP/dPTP) to evaluate the presence of cryptic species. Linear Discriminant Analysis was used to test whether the linear combination of 21 variables (ratios of morphological measurements) can predict individual’s membership to a putative species. Results. Genetic and morphological data suggest that U. yaschenkoi is a species complex. High statistical support for the monophyly of several divergent lineages was found both at the mitochondrial loci and at a nuclear locus. The extent of mitochondrial divergence between these lineages exceeds estimates of interspecific divergence reported for other scorpion groups. The GMYC model and the PTP/bPTP approach identified major lineages and several sub-lineages as putative species. Ratios of several traits that approximate body shape had a strong predictive power (83–100%) in discriminating two major molecular lineages. A time-calibrated phylogeny dates the early divergence at the onset of continental-wide aridification in late Miocene and Pliocene, with finer-scale phylogeographic patterns emerging during the Pleistocene. This structuring dynamics is congruent with the diversification history of other fauna of the Australian arid zones. Discussion. Our results indicate that the taxonomic status of U. yaschenkoi requires revision, and we provide recommendations for such future efforts. A complex evolutionary history and extensive diversity highlights the importance of conserving U. yaschenkoi populations from different Australian arid zones in order to preserve patterns of endemism and evolutionary potential.


Flora ◽  
2014 ◽  
Vol 209 (2) ◽  
pp. 117-121 ◽  
Author(s):  
Luana Silva Braucks Calazans ◽  
Cassia Mônica Sakuragui ◽  
Simon Joseph Mayo

2019 ◽  
Vol 116 (6) ◽  
pp. 2146-2151 ◽  
Author(s):  
Tetsuto Miyashita ◽  
Michael I. Coates ◽  
Robert Farrar ◽  
Peter Larson ◽  
Phillip L. Manning ◽  
...  

Hagfish depart so much from other fishes anatomically that they were sometimes considered not fully vertebrate. They may represent: (i) an anatomically primitive outgroup of vertebrates (the morphology-based craniate hypothesis); or (ii) an anatomically degenerate vertebrate lineage sister to lampreys (the molecular-based cyclostome hypothesis). This systematic conundrum has become a prominent case of conflict between morphology- and molecular-based phylogenies. To date, the fossil record has offered few insights to this long-branch problem or the evolutionary history of hagfish in general, because unequivocal fossil members of the group are unknown. Here, we report an unequivocal fossil hagfish from the early Late Cretaceous of Lebanon. The soft tissue anatomy includes key attributes of living hagfish: cartilages of barbels, postcranial position of branchial apparatus, and chemical traces of slime glands. This indicates that the suite of characters unique to living hagfish appeared well before Cretaceous times. This new hagfish prompted a reevaluation of morphological characters for interrelationships among jawless vertebrates. By addressing nonindependence of characters, our phylogenetic analyses recovered hagfish and lampreys in a clade of cyclostomes (congruent with the cyclostome hypothesis) using only morphological data. This new phylogeny places the fossil taxon within the hagfish crown group, and resolved other putative fossil cyclostomes to the stem of either hagfish or lamprey crown groups. These results potentially resolve the morphological–molecular conflict at the base of the Vertebrata. Thus, assessment of character nonindependence may help reconcile morphological and molecular inferences for other major discords in animal phylogeny.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2759 ◽  
Author(s):  
Karen Luna-Ramirez ◽  
Adam D. Miller ◽  
Gordana Rašić

BackgroundAustralian scorpions have received far less attention from researchers than their overseas counterparts. Here we provide the first insight into the molecular variation and evolutionary history of the endemic Australian scorpionUrodacus yaschenkoi. Also known as the inland robust scorpion, it is widely distributed throughout arid zones of the continent and is emerging as a model organism in biomedical research due to the chemical nature of its venom.MethodsWe employed Bayesian Inference (BI) methods for the phylogenetic reconstructions and divergence dating among lineages, using unique haplotype sequences from two mitochondrial loci (COXI, 16S) and one nuclear locus (28S). We also implemented two DNA taxonomy approaches (GMYC and PTP/dPTP) to evaluate the presence of cryptic species. Linear Discriminant Analysis was used to test whether the linear combination of 21 variables (ratios of morphological measurements) can predict individual’s membership to a putative species.ResultsGenetic and morphological data suggest thatU. yaschenkoiis a species complex. High statistical support for the monophyly of several divergent lineages was found both at the mitochondrial loci and at a nuclear locus. The extent of mitochondrial divergence between these lineages exceeds estimates of interspecific divergence reported for other scorpion groups. The GMYC model and the PTP/bPTP approach identified major lineages and several sub-lineages as putative species. Ratios of several traits that approximate body shape had a strong predictive power (83–100%) in discriminating two major molecular lineages. A time-calibrated phylogeny dates the early divergence at the onset of continental-wide aridification in late Miocene and Pliocene, with finer-scale phylogeographic patterns emerging during the Pleistocene. This structuring dynamics is congruent with the diversification history of other fauna of the Australian arid zones.DiscussionOur results indicate that the taxonomic status ofU. yaschenkoirequires revision, and we provide recommendations for such future efforts. A complex evolutionary history and extensive diversity highlights the importance of conservingU. yaschenkoipopulations from different Australian arid zones in order to preserve patterns of endemism and evolutionary potential.


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