scholarly journals Should we be concerned about incomplete taxon sampling when assessing the evolutionary history of regional biotas?

2021 ◽  
Author(s):  
Rafael Molina‐Venegas ◽  
Herlander Lima
Zoomorphology ◽  
2021 ◽  
Author(s):  
Philipp Thieme ◽  
Timo Moritz

AbstractThe accessory neural arch is an oddly distributed character present in several non-acanthomorph teleostean taxa. Its homology was often implied but never satisfyingly tested. In this study, we attended this pending problem. We analyzed the morphology, development, and systematic distribution of the accessory neural arch in teleosts. Using a comprehensive taxon sampling of cleared and stained specimens, we evaluated if the accessory neural arch fulfils existing homology criteria. We then combined these data with recent genetic phylogenies and ancestral character state estimation to reconstruct the evolutionary history of the accessory neural arch. While its gross morphology and development fit homology criteria, results from ancestral character state estimations suggest multiple independent evolutions within teleosts. Although the accessory neural arch cannot be homologous between several teleostean taxa, the concept of parallelism may explain the presence of such a similar character in a variety of non-acanthomorph teleostean taxa.


2019 ◽  
Vol 104 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Mónica M. Carlsen ◽  
Thomas B. Croat

This study presents an evaluation of the currently accepted sectional classification of the genus Anthurium Schott (Araceae) in light of a recently published molecular phylogeny for the group. In general, disagreements between these two occur because many diagnostic morphological characters used in the sectional classification turned out to be highly homoplasious within Anthurium, with multiple independent gains or losses of seemingly similar morphologies in distantly related clades. A new sectional classification of Anthurium that more accurately represents species relationships and the evolutionary history of the genus is much needed, and here we propose the first steps toward it. Results from this study suggest that out of the 18 sections and two series recognized in Anthurium, only seven of these groups are monophyletic (i.e., sections Andiphilum (Schott) Croat, Calomystrium (Schott) Engl., Dactylophyllium (Schott) Engl., Leptanthurium (Schott) Engl., Polyphyllium Engl., Tetraspermium (Schott) Engl., and the newly recognized section Multinervia (Croat) Carlsen & Croat, previously a series within section Pachyneurium (Schott) Engl.). All other sections are either not monophyletic or their monophyly could not be accurately tested. A complete revision of the sectional classification of Anthurium will require a more comprehensive taxon sampling and a better supported molecular phylogeny.


Author(s):  
Robert J Kallal ◽  
Dimitar Dimitrov ◽  
Miquel A Arnedo ◽  
Gonzalo Giribet ◽  
Gustavo Hormiga

Abstract We address some of the taxonomic and classification changes proposed by Kuntner et al. (2019) in a comparative study on the evolution of sexual size dimorphism in nephiline spiders. Their proposal to recircumscribe araneids and to rank the subfamily Nephilinae as a family is fundamentally flawed as it renders the family Araneidae paraphyletic. We discuss the importance of monophyly, outgroup selection, and taxon sampling, the subjectivity of ranks, and the implications of the age of origin criterion to assign categorical ranks in biological classifications. We explore the outcome of applying the approach of Kuntner et al. (2019) to the classification of spiders with emphasis on the ecribellate orb-weavers (Araneoidea) using a recently published dated phylogeny. We discuss the implications of including the putative sister group of Nephilinae (the sexually dimorphic genus Paraplectanoides) and the putative sister group of Araneidae (the miniature, monomorphic family Theridiosomatidae). We propose continuation of the phylogenetic classification put forth by Dimitrov et al. (2017), and we formally rank Nephilinae and Phonognathinae as subfamilies of Araneidae. Our classification better reflects the understanding of the phylogenetic placement and evolutionary history of nephilines and phonognathines while maintaining the diagnosability of Nephilinae. It also fulfills the fundamental requirement that taxa must be monophyletic, and thus avoids the paraphyly of Araneidae implied by Kuntner et al. (2019).


2020 ◽  
Author(s):  
Dario Karmeinski ◽  
Karen Meusemann ◽  
Jessica A. Goodheart ◽  
Michael Schroedl ◽  
Alexander Martynov ◽  
...  

AbstractBackgroundCladobranch sea slugs represent roughly half of the biodiversity of soft-bodied, marine gastropod molluscs (Nudibranchia) on the planet. Despite their global distribution from shallow waters to the deep sea, from tropical into polar seas, and their important role in marine ecosystems and for humans (as bioindicators and providers of medical drug leads), the evolutionary history of cladobranch sea slugs is not yet fully understood. Here, we amplify the current knowledge on the phylogenetic relationships by extending the cladobranch and outgroup taxon sampling using transcriptome data.ResultsWe generated new transcriptome data for 19 species of cladobranch sea slugs and two additional outgroup taxa. We complemented our taxon sampling with previously published transcriptome data, resulting in a final supermatrix covering 56 species from all but one accepted cladobranch superfamilies. Transcriptome assembly using six different assemblers, selection of those assemblies providing the largest amount of potentially phylogenetically informative sites, and quality-driven compilation of data sets resulted in three different supermatrices: one with a full coverage of genes per species (446 single-copy protein-coding genes) and two with a less stringent coverage (667 genes with 98.9% partition coverage and 1,767 genes with 86% partition coverage, respectively). We used these supermatrices to infer statistically robust maximum-likelihood trees. All analyses, irrespective of the data set, indicate maximum statistical support for all major splits and phylogenetic relationships on family level. The only discordance between the inferred trees is the position of Embletonia pulchra. Extensive testing using Four-cluster Likelihood Mapping, Approximately Unbiased tests, and Quartet Scores revealed that its position is not due to any informative phylogenetic signal, but caused by confounding signal.ConclusionsOur data matrices and the inferred trees inferred can serve as a solid foundation for future work on the taxonomy and evolutionary history of Cladobranchia. The correct placement of E. pulchra, however, proves challenging, even with large data sets. Moreover, quartet mapping shows that confounding signal present in the data is sufficient to explain the inferred position of E. pulchra, again leaving its phylogenetic position as an enigma.


2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.


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