Echinoderm phylogeny: how congruent are morphological and molecular estimates?

1997 ◽  
Vol 3 ◽  
pp. 337-355 ◽  
Author(s):  
Andrew B. Smith

Single data sets, whether derived from morphological or molecular evidence, provide one-off estimates of the correct phylogeny. Their reliability can only be gauged by statistical approaches such as bootstrapping or clade decay, but these test only whether there are sufficient characters in the data matrix to justify the groupings identified. They do not test whether the characters themselves are reliable. Consequently, confidence in the correctness of phylogenetic interpretations comes primarily from discovering the same (or statistically indistinguishable) patterns from independent data sets.Congruence studies are most advanced for echinoids, where four independent data sets (two morphological and two molecular) provide strong corroboration for a single phylogenetic scheme. Analysis of all four data sets combined generates a highly robust hypothesis of relationships. The situation is very different for asteroids. Two analyses based on morphological data have reached very different conclusions. Three independent molecular data sets also have been compiled, but none has a statistically reliable signal concerning higher taxon relationships. Even combining all three molecular data sets fails to generate a statistically robust solution, implying that the major lines of asteroids diverged rapidly from one another. For ophiuroids, both morphological and molecular data generate topologies that for the most part lack statistical robustness. There is currently no cladistic analysis of holothurian relationships based on morphological data, and only a few taxa have been sequenced. The molecular data is, however, congruent and does permit an initial assessment of relationships. Nothing definite can be deduced about crinoid relationships since even fewer molecular sequences are known and morphological analysis remains sketchy.Class-level relationships derived from two morphological and two molecular data sets also show considerable congruence, though a single definitive solution has yet to emerge.

1993 ◽  
Vol 24 (2) ◽  
pp. 121-137 ◽  
Author(s):  
Ward C. Wheeler ◽  
Ranhy Bang ◽  
Randall T. Schuh

AbstractThe monophyly of the 7 infraorders of Heteroptera and history of higher group concepts and interrelationships within the Heteroptera are briefly reviewed. Data from 31 morphological characters are combined with 669 bases of 18S nuclear rDNA for 29 taxa, including several outgroups to the Heteroptera, to produce a phylogeny based on the total available evidence. The molecular data alone and in conjunction with morphological data indicate that: the Homoptera are probably not monophyletic; the Auchenorrhyncha are the sister group of Coleorrhyncha + Heteroptera ; the Enicocephalomorpha are the sister group of remaining Heteroptera; the Dipsocoromorpha are the sister group of remaining Heteroptera; the Gerromorpha are the sister group of remaining Heteroptera; the Nepomorpha are the sister group of remaining Heteroptera; the Leptopodomorpha are the sister group of the Cimicomorpha + Pentatomomorpha. The molecular evidence corroborates the morphologically based theory of a sister group relationship between Aradoidea and trichophoran Pentatomomorpha. This scheme deviates from that previously published by Schuh, in which the Leptopodomorpha were treated as the sister group of the Nepomorpha.


2021 ◽  
Author(s):  
Jack Oyston ◽  
Mark Wilkinson ◽  
Marcello Ruta ◽  
Matthew Wills

Abstract Phylogenetic relationships are inferred principally from two classes of data: morphological and molecular. Most current phylogenies of extant taxa are inferred from molecules, and when morphological and molecular trees conflict the latter are often preferred. Although supported by simulations, the superiority of molecular trees has never been assessed empirically. Here we test phylogenetic accuracy using two independent data sources: biogeographical distributions and fossil first occurrences. For 48 pairs of morphological and molecular trees, we show that molecular trees are, on average, significantly more biogeographically congruent than their morphological counterparts. We also report an increase in the biogeographical congruence of phylogenies over research time. We find no significant differences in stratigraphical congruence between morphological and molecular trees. These findings have implications for understanding homoplasy in morphological data sets, the utility of morphology as a test of molecular hypotheses, and the difficulty of analysing fossil groups for which molecular data are unavailable.


Zootaxa ◽  
2021 ◽  
Vol 4991 (3) ◽  
pp. 401-433
Author(s):  
TOMASZ W. PYRCZ ◽  
KLAUDIA FLORCZYK ◽  
STEVE COLLINS ◽  
SZABOLCS SÁFIÁN ◽  
OSCAR MAHECHA-J. ◽  
...  

The tribe Junoniini is a predominantly Paleotropical group of the cosmopolitan butterfly subfamily Nymphalinae (Nymphalidae), with highest diversity in the Afrotropical region. Its systematics and relationships are not entirely resolved. Question marks remain concerning the validity of some genera; and the apparently close relationship between the Indo-Australian genus Yoma and the Afrotropical Protogoniomorpha, as evidenced by molecular phylogenies, remains a puzzle. Here, we present a cladistic analysis, based on 42 characters of the male and female genitalia of 41 species of Junoniini belonging to six genera, nearly all of them continental Afrotropical, and 3 species of two Indo-Australian genera Yoma and Rhinopalpa. A ML COI-based tree is produced for 36 species of Afrotropical Junoniini and Yoma. The molecular data are consistent with previous studies. However, morphological analysis does not confirm a close relationship between Protogoniomorpha and Yoma. Despite the evolution of a number of modifications, the male genitalia within all genera and species of the Junoniini share a cohesive build plan, in particular a transformed sacculus, from which Yoma is highly divergent. The position of the genus Kamilla, previously synonymized with Junonia, is discussed. Three East African coast taxa, Junonia elgiva stat. reinst., Protogoniomorpha nebulosa stat. reinst. and Salamis amaniensis stat. reinst., and one from central Africa, Precis silvicola stat. reinst. are raised to species level, based on comparative analysis of their male genitalia.  


2017 ◽  
Author(s):  
Ross Mounce

In this thesis I attempt to gather together a wide range of cladistic analyses of fossil and extant taxa representing a diverse array of phylogenetic groups. I use this data to quantitatively compare the effect of fossil taxa relative to extant taxa in terms of support for relationships, number of most parsimonious trees (MPTs) and leaf stability. In line with previous studies I find that the effects of fossil taxa are seldom different to extant taxa – although I highlight some interesting exceptions. I also use this data to compare the phylogenetic signal within vertebrate morphological data sets, by choosing to compare cranial data to postcranial data. Comparisons between molecular data and morphological data have been previously well explored, as have signals between different molecular loci. But comparative signal within morphological data sets is much less commonly characterized and certainly not across a wide array of clades. With this analysis I show that there are many studies in which the evidence provided by cranial data appears to be be significantly incongruent with the postcranial data – more than one would expect to see just by the effect of chance and noise alone. I devise and implement a modification to a rarely used measure of homoplasy that will hopefully encourage its wider usage. Previously it had some undesirable bias associated with the distribution of missing data in a dataset, but my modification controls for this. I also take an in-depth and extensive review of the ILD test, noting it is often misused or reported poorly, even in recent studies. Finally, in attempting to collect data and metadata on a large scale, I uncovered inefficiencies in the research publication system that obstruct re-use of data and scientific progress. I highlight the importance of replication and reproducibility – even simple reanalysis of high profile papers can turn up some very different results. Data is highly valuable and thus it must be retained and made available for further re-use to maximize the overall return on research investment.


2009 ◽  
Vol 34 (3) ◽  
pp. 580-594 ◽  
Author(s):  
Anthony R. Magee ◽  
Ben-Erik van Wyk ◽  
Patricia M. Tilney ◽  
Stephen R. Downie

Generic circumscriptions and phylogenetic relationships of the Cape genera Capnophyllum, Dasispermum, and Sonderina are explored through parsimony and Bayesian inference analyses of nrDNA ITS and cpDNA rps16 intron sequences, morphology, and combined molecular and morphological data. The relationship of these genera with the North African genera Krubera and Stoibrax is also assessed. Analyses of both molecular data sets place Capnophyllum, Dasispermum, Sonderina, and the only southern African species of Stoibrax (S. capense) within the newly recognized Lefebvrea clade of tribe Tordylieae. Capnophyllum is strongly supported as monophyletic and is distantly related to Krubera. The monotypic genus Dasispermum and Stoibrax capense are embedded within a paraphyletic Sonderina. This complex is distantly related to the North African species of Stoibrax in tribe Apieae, in which the type species, Stoibrax dichotomum, occurs. Consequently, Dasispermum is expanded to include both Sonderina and Stoibrax capense. New combinations are formalized for Dasispermum capense, D. hispidum, D. humile, and D. tenue. An undescribed species from the Tanqua Karoo in South Africa is also closely related to Capnophyllum and the Dasispermum–Sonderina complex. The genus Scaraboides is described herein to accommodate the new species, S. manningii. This monotypic genus shares the dorsally compressed fruit and involute marginal wings with Capnophyllum, but is easily distinguished by its erect branching habit, green leaves, scabrous umbels, and fruit with indistinct median and lateral ribs, additional solitary vittae in each marginal wing, and parallel, closely spaced commissural vittae. Despite the marked fruit similarities with Capnophyllum, analyses of DNA sequence data place Scaraboides closer to the Dasispermum–Sonderina complex, with which it shares the erect habit, green (nonglaucous) leaves, and scabrous umbels.


Zootaxa ◽  
2004 ◽  
Vol 680 (1) ◽  
pp. 1 ◽  
Author(s):  
ARNE NYGREN

Autolytinae is revised based on available types, and newly collected specimens. Out of 170 nominal species, 18 are considered as incertae sedis, 43 are regarded as junior synonyms, and 25 are referred to as nomina dubia. The relationships of Autolytinae is assessed from 51 morphological characters and 211 states for 76 ingroup-taxa, and 460 molecular characters from mitochondrial 16S rDNA and nuclear 18S rDNA for 31 ingroup-taxa; outgroups include 12 non-autolytine syllid polychaetes. Two analyses are provided, one including morphological data only, and one with combined morphological and molecular data sets. The resulting strict consensus tree from the combined data is chosen for a reclassification. Three main clades are identified: Procerini trib. n., Autolytini Grube, 1850, and Epigamia gen. n. Proceraea Ehlers, 1864 and Myrianida Milne Edwards, 1845 are referred to as nomen protectum, while Scolopendra Slabber, 1781, Podonereis Blainville, 1818, Amytis Savigny, 1822, Polynice Savigny, 1822, and Nereisyllis Blainville, 1828 are considered


Zootaxa ◽  
2017 ◽  
Vol 4242 (2) ◽  
pp. 313
Author(s):  
MAURICIO RIVERA-CORREA ◽  
CARLOS JIMÉNEZ-RIVILLAS ◽  
JUAN M. DAZA

Pristimantis, distributed throughout the New World tropics, is the most speciose vertebrate genus. Pristimantis presents an enormous morphological diversity and is currently divided into several demonstrably non-monophyletic phenetic species groups. With the purpose of increasing our understanding of Pristimantis systematics, we present the first phylogenetic analysis using molecular evidence to test the monophyly and infer evolutionary relationships within the Pristimantis leptolophus group, an endemic group of frogs from the highlands of the Colombian Andes. Our phylogenetic reconstruction recovers the group as monophyletic with high support, indicating general concordance between molecular data and morphological data. In addition, we describe a new polymorphic species lacking conspicuous tubercles, a regular attribute among species of the P. leptolophus species group and endemic from the Páramo de Sonsón complex (Antioquia, Colombia). The phylogenetic position of the new species is inferred and other systematic implications in the light of our results are discussed. 


2005 ◽  
Vol 1 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Michael S.Y Lee

A molecular phylogeny was used to refute the marine scenario for snake origins. Nuclear gene sequences suggested that snakes are not closely related to living varanid lizards, thus also apparently contradicting proposed relationships between snakes and marine mosasaurs (usually considered to be varanoids). However, mosasaurs share derived similarities with both snakes and living varanids. A reanalysis of the morphological data suggests that, if the relationships between living taxa are constrained to the proposed molecular tree, with fossil forms allowed to insert in their optimal positions within this framework, mosasaurs cluster with snakes rather than with varanids. Combined morphological and molecular analyses also still unite marine lizards with snakes. Thus, the molecular data do not refute the phylogenetic evidence for a marine origin of snakes.


Bothalia ◽  
1996 ◽  
Vol 26 (2) ◽  
pp. 167-175 ◽  
Author(s):  
M. T. R. Schubert ◽  
B-E. Van Wyk ◽  
F. H. Van der Bank ◽  
M. Van der Bank

The main aim of this paper is to explore the occurrence of hybridization in the genus Centella. Morphological as well as genetic characters are investigated to confirm the identity of a putative hybrid between C.  triloba and C. macrocarpa. These two independent data sets, one from enzyme electrophoresis and one from morphology, are compared and interpreted by means of cladistic analysis.  Centella glauca and C.  virgata were included in the analysis and the effect of hybridization on cladistics is demonstrated. Hybridization gives a new perspective on infrageneric relationships within the genus Centella, as it may have obscured discontinuities between previously discrete infrageneric groups.


2021 ◽  
Author(s):  
E. J. Thompson ◽  
Melodina Fabillo

The taxonomy of Neurachninane has been unstable, with its member genera consisting of Ancistrachne, Calyptochloa, Cleistochloa, Dimorphochloa, Neurachne, Paraneurachne and Thyridolepis, changing since its original circumscription that comprised only the latter three genera. Recent studies on the phylogeny of Neurachninae have focused primarily on molecular data. We analysed the phylogeny of Neurachninae on the basis of molecular data from seven molecular loci (plastid markers: matK, ndhF, rbcL, rpl16, rpoC2 and trnLF, and ribosomal internal transcribed spacer, ITS) and morphological data from 104 morphological characters, including new taxonomically informative micromorphology of upper paleas. We devised an impact assessment scoring (IAS) protocol to aid selection of a tree for inferring the phylogeny of Neurachninae. Combining morphological and molecular data resulted in a well resolved phylogeny with the highest IAS value. Our findings support reinstatement of subtribe Neurachninae in its original sense, Neurachne muelleri and Dimorphochloa rigida. We show that Ancistrachne, Cleistochloa and Dimorphochloa are not monophyletic and Ancistrachne maidenii, Calyptochloa, Cleistochloa and Dimorphochloa form a new group, the cleistogamy group, united by having unique morphology associated with reproductive dimorphism.


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