A Reexamination of Species Boundaries Between Solanum megistacrolobum and S. toralapanum (Solanum sect. Petota, series Megistacroloba): Morphological Data

1994 ◽  
Vol 19 (1) ◽  
pp. 89 ◽  
Author(s):  
Robert B. Giannattasio ◽  
David M. Spooner
Keyword(s):  
Morphological Data ◽  
Species Boundaries ◽  
Solanum Sect

Inferring species boundaries using acoustic and morphological data in the ground cricket genus Gymnogryllus (Orthoptera: Grylloidea: Gryllinae)

2018 ◽  
Vol 16 (8) ◽  
pp. 731-742 ◽  
Author(s):  
Ming Kai Tan ◽  
Crystal Yun Han Yong ◽  
Sigfrid Ingrisch ◽  
Hanyrol H. Ahmad Sah ◽  
Rodzay bin Haji Abdul Wahab ◽  
...  
Keyword(s):  
Morphological Data ◽  
Species Boundaries

A Morphometric Study of Species Boundaries of the Wild Potato Solanum Series Piurana (Solanaceae) and Putatively Related Species from Seven Other Series in Solanum Sect. Petota

2008 ◽  
Vol 33 (3) ◽  
pp. 566-578 ◽  
Author(s):  
Mercedes Ames ◽  
Alberto Salas ◽  
David M. Spooner
Keyword(s):  
United States ◽  
Related Species ◽  
Species Boundaries ◽  
Morphometric Study ◽  
Wild Potato ◽  
Morphological Similarity ◽  
Field Station ◽  
Constituent Species ◽  
Solanum Sect ◽  
Germplasm Accessions

There are about 190 wild potato (Solanum L. section Petota Dumort.) species distributed from the southwestern United States to central Argentina and adjacent Chile and Uruguay. The morphological similarity of many of its constituent species has led to widely conflicting taxonomic treatments. Solanum series Piurana Hawkes is one of 21 series recognized in section Petota in the latest comprehensive taxonomic treatment by Hawkes in 1990. They are distributed from southern Colombia, south through Ecuador to central Peru. The limits of the series and validity of its constituent species are unresolved. We provide the first comprehensive morphological phenetic study of the series, to include putatively related species in ser. Conicibaccata, Cuneoalata, Ingifolia, Megistacroloba, Simplicissima, Tuberosa, and Yungasensa, through an examination 188 living germplasm accessions of 33 species, planted in replicated plots in a field station in Andean Peru. Only four morphologically well-defined groups were supported. Continuing work is exploring molecular support for these species in these eight series.

scholarly journals A morphometric assessment of species boundaries in a widespread anole lizard (Squamata: Dactyloidae)

2020 ◽  
Vol 130 (4) ◽  
pp. 813-825
Author(s):  
Tanner C Myers ◽  
Pietro L H de Mello ◽  
Richard E Glor
Keyword(s):  
Cryptic Species ◽  
Model Fitting ◽  
Taxonomic Revision ◽  
Genetic Data ◽  
Morphological Data ◽  
Species Boundaries ◽  
Morphometric Data ◽  
Normal Mixture ◽  
Test Species ◽  
Candidate Species

Abstract Cryptic species – genetically distinct species that are morphologically difficult to distinguish – present challenges to systematists. Operationally, cryptic species are very difficult to identify and sole use of genetic data or morphological data can fail to recognize evolutionarily isolated lineages. We use morphometric data to test species boundaries hypothesized with genetic data in the North Caribbean bark anole (Anolis distichus), a suspected species complex. We use univariate and multivariate analyses to test if candidate species based on genetic data can be accurately diagnosed. We also test alternative species delimitation scenarios with a model fitting approach that evaluates normal mixture models capable of identifying morphological clusters. Our analyses reject the hypothesis that the candidate species are diagnosable. Neither uni- nor multivariate morphometric data distinguish candidate species. The best-supported model included two morphological clusters; however, these clusters were uneven and did not align with a plausible species divergence scenario. After removing two related traits driving this result, only one cluster was supported. Despite substantial differentiation revealed by genetic data, we recover no new evidence to delimit species and refrain from taxonomic revision. This study highlights the importance of considering other types of data along with molecular data when delimiting species.

The molecularisation of taxonomy

2004 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
Michael S. Y. Lee
Keyword(s):  
Dna Sequences ◽  
Sequence Divergence ◽  
Biological Information ◽  
Morphological Data ◽  
Single Type ◽  
Species Boundaries ◽  
Character State ◽  
State Identity ◽  
Test Species ◽  
Taxonomic Framework

The recent proposal for a new system of biological taxonomy based primarily on DNA sequences from one or a few chosen ('standard') genes sequenced across all taxa appears inadvisable for both practical and theoretical reasons. While nucleotide sequences are more objective than traditional (e.g. morphological) data in some respects (character choice, character delineation, character state identity), in other respects both are inherently subjective (homology/alignment, divergence metrics). Sequence divergence in standard gene(s) is an extremely crude method for determining species limits; more appropriate markers (potentially directly linked to species criteria such as reproductive isolation) should be and often are used. It is thus worth persisting with the plurality of genetic, anatomical and ethological criteria currently used to hypothesise ('identify') and test species boundaries. However, once species boundaries have been thus discerned, use of sequences from standard genes to diagnose those boundaries (and place individuals with respect to those boundaries) is highly feasible, though subject to error like any single type of marker. In many cases this approach might have advantages over morphological diagnoses. However, unless an appropriate taxonomic framework constructed using all appropriate biological information is already in place, such molecular diagnoses will be premature.

What’s under the hood? Phylogeny and taxonomy of the snake genera Parasuta Worrell and Suta Worrell (Squamata: Elapidae), with a description of a new species from the Pilbara, Western Australia

Zootaxa ◽  
2020 ◽  
Vol 4778 (1) ◽  
pp. 1-47
Author(s):  
BRAD MARYAN ◽  
IAN G. BRENNAN ◽  
MARK N. HUTCHINSON ◽  
LUKAS S. GEIDANS
Keyword(s):  
Western Australia ◽  
Molecular Genetic ◽  
Taxonomic Revision ◽  
Species Level ◽  
Morphological Data ◽  
Species Boundaries ◽  
Phylogenetic Studies ◽  
Senior Synonym ◽  
Molecular Phylogenetic ◽  
The Many

Despite decades of phylogenetic studies, the generic and species-level relationships of some Australian elapid snakes remain problematic. The morphologically conservative genus Parasuta comprises small nocturnal snakes with a particularly obfuscated taxonomic history. Here we provide a molecular phylogenetic analysis of all currently recognised species including members of the sister genus Suta and provide new morphological data that lead to a taxonomic revision of generic and species boundaries. We failed to find support for monophyly of Parasuta or Suta, instead supporting previous evidence that these two genera should be combined. Our species-level investigations revise the boundaries between P. gouldii (Gray) and P. spectabilis (Krefft) resulting in recognition that both P. spectabilis bushi (Storr) and P. spectabilis nullarbor (Storr) are conspecific with P. gouldii. We also find the Pilbara population of P. monachus (Storr) to be specifically distinct. As a consequence of this information, we synonymise Parasuta with its senior synonym Suta, redescribe S. gouldii, S. monachus and S. spectabilis to clarify morphological and geographical boundaries and describe S. gaikhorstorum sp. nov., which differs from all other described Suta species, including the geographically proximate and similar-looking S. monachus, by a combination of molecular genetic markers, morphometric attributes, details of colouration and scalation. The recognition of S. gaikhorstorum sp. nov. adds to the growing list of the many endemic reptiles from this exceptionally diverse biotic region. We also designate a lectotype for S. spectabilis from the original syntype series, highlight a distinctive population from the Great Victoria Desert in Western Australia and comment on further unresolved issues regarding the relationships between S. dwyeri (Worrell) and S. nigriceps (Gȕnther).  

The evolutionary history and molecular systematics of the Musteloidea

2018 ◽  
Author(s):  
Klaus-Peter Koepfli ◽  
Jerry W. Dragoo ◽  
Xiaoming Wang
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Molecular Data ◽  
Morphological Data ◽  
Species Boundaries ◽  
Extant Species ◽  
Taxonomic History ◽  
History Of ◽  
A New Species

This chapter provides a review of the evolutionary and taxonomic history of the Musteloidea, which is the most species-rich superfamily of the Carnivora, containing approximately 30% of the extant species in the order. An up-to-date summary of knowledge on the evolutionary and taxonomic history and phylogenetic relationships of the Mephitidae, Ailuridae, Procyonidae and Mustelidae is provided. Multilocus DNA sequences have made a large impact on the understanding of phylogenetic relationships among the Musteloidea. Molecular data have revealed distinct families (Ailuridae and Mephitidae) within the Musteloidea and have illuminated new relationships based on tempo and patterns of evolution within the Procyonidae. Morphological data in conjunction with molecular data have been used to elucidate species boundaries within certain musteloid genera and have led to the discovery of a new species. Research studies published during the last 30 years have enriched and transformed our understanding of the evolution of musteloid biodiversity.

Another stripe on the tiger makes no difference? Unexpected diversity in the widespread tiger tarantula Davus pentaloris (Araneae: Theraphosidae: Theraphosinae)

2020 ◽  
Author(s):  
Daniela T Candia-Ramírez ◽  
Oscar F Francke
Keyword(s):  
Morphological Variation ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
Variable Number ◽  
Morphological Data ◽  
Species Boundaries ◽  
Morphological Evidence ◽  
Multiple Sources ◽  
Candidate Species ◽  
Different Sources

Abstract Integrative taxonomy is relevant for the discovery and delimitation of cryptic species by incorporating different sources of evidence to construct rigorous species hypotheses. The genus Davus was recently revised and it was found that Davus pentaloris presents high morphological variation across its widespread distribution. However, tarantulas usually present low dispersal capabilities that occasionally result in local endemism. In order to evaluate species boundaries within this taxon, we examine the morphological variation and, additionally, employ four strategies based on mtDNA data (COI): two distance-based [automatic barcode gap discovery (ABGD) and Neighbor-Joining (NJ)] and two tree-based methods [general mixed Yule coalescent (GMYC) and Bayesian Poisson tree process (bPTP)]. Available morphological evidence recovers 13 putative morphospecies, but the different methods based on molecular data recover a variable number of candidate species (16–18). Based on the congruence across all analyses and the available morphological data, we recognize 13 clearly diagnosable species, 12 of them new to science. We conclude that the underestimation of the diversity in D. pentaloris was mainly caused by deficient practices in taxonomy, rather than by the presence of cryptic diversity. Although COI is a functional barcoding marker and it gives reliable results in our study, we recommend combining multiple sources of evidence and strategies to construct better species delimitation hypotheses.

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