Osteology in the Cuora galbinifrons complex suggests conspecifity of C. bourreti and C. galbinifrons, with notes on shell osteology and phalangeal formulae within the Geoemydidae

2006 ◽  
Vol 27 (2) ◽  
pp. 195-205 ◽  
Author(s):  
Uwe Fritz ◽  
Markus Auer ◽  
Antje Petzold
Keyword(s):  
Hainan Island ◽  
Biological Species ◽  
Shell Shape ◽  
Biological Species Concept ◽  
Character State ◽  
Genetic Introgression ◽  
X Rays ◽  
Part C ◽  
Fourth Finger ◽  
Phalangeal Formula

AbstractThirty-six complete skeletons, three shells, and x-rays of the extremities of 32 additional turtles of the Cuora galbinifrons complex have been compared with 38 other geoemydid species from 19 genera. Cuora bourreti differs from C. galbinifrons and C. picturata by a lost phalanx in the fourth finger and fourth toe. Individuals with a shell shape intermediate between C. bourreti and C. galbinifrons, as found on Hainan Island (China), have either the reduced phalangeal formula of C. bourreti (manus: 2-3-3-2-2, pes: 2-3-3-2-1) or the complete number of phalanges (manus: 2-3-3-3-2, pes: 2-3-3-3-1). Only in C. flavomarginata did we also register a lost phalanx in the fourth digit of manus and pes; in the pes of C. mouhotii the same character state may occur. In C. flavomarginata the fifth digit of the pes is also lacking. Some other terrestrial and semiterrestrial geoemydids (Cuora mccordi, Heosemys spinosa, and in part C. mouhotii and Leucocephalon yuwonoi) display a similar pattern of phalangeal reduction, resulting in the loss of the fifth digit of the pes. Likewise, in tortoises (Testudinidae), a further group of terrestrial chelonians, and the terrestrial turtle genus Terrapene (Emydidae) the loss of phalanges or complete digits is known to occur. Malayemys subtrijuga, Morenia petersi, Pangshura smithii and Siebenrockiella crassicollis differ from all other studied geoemydid taxa by an additional phalanx in the fifth digit of the manus (2-3-3-3-3); one P. smithii has on one body side three phalanges in the fifth digit of the pes (2-3-3-3-3). These are highly aquatic turtles with extensive toe webbing. Probably, longer digits (and thus a higher phalangeal number) are a favorable prerequisite for swimming while phalangeal loss seems to be the consequence of walking.Cuora bourreti and C. picturata have consistently in the bony carapace a very rare character state regarding the articulation of the rib tips with the peripheral plates. In both species the rib tips are intercalated between two peripheral plates in the bridge region. Intercalated rib tips like those in C. bourreti and C. picturata were found only in C. m. mouhotii, but not in the southern subspecies C. mouhotii obsti. In C. galbinifrons and all other geoemydid taxa studied the rib tips articulate on the bridge within the underlying peripheral and not between two peripherals. In turtles morphologically intermediate between C. bourreti and C. galbinifrons both characters states are found. This suggests that such individuals are hybrids or intergrades. Three known-locality specimens from Hainan Island display both extremes and an intermediate character state. This, together with external morphology and the occurrence of both phalangeal formulae in approximately the same frequency on that island, argues for genetic introgression of C. bourreti on the Hainan population of C. galbinifrons. We conclude that our findings qualify C. galbinifrons and C. bourreti under the Biological Species Concept as conspecific.

scholarly journals Some Examples of the Use of Molecular Markers for Needs of Basic Biology and Modern Society

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1473
Author(s):  
Yuri Phedorovich Kartavtsev
Keyword(s):  
Meta Analysis ◽  
Molecular Genetic ◽  
Modern Society ◽  
Molecular Data ◽  
Biological Species ◽  
Social Needs ◽  
Biological Species Concept ◽  
Genetic Introgression ◽  
Gene Trees ◽  
Modern Biology

Application of molecular genetic markers appeared to be very fruitful in achieving many goals, including (i) proving the theoretic basements of general biology and (ii) assessment of worldwide biodiversity. Both are provided in the present meta-analysis and a review as the main signal. One of the basic current challenges in modern biology in the face of new demands in the 21st century is the validation of its paradigms such as the synthetic theory of evolution (STE) and biological species concept (BSC). Another of most valuable goals is the biodiversity assessment for a variety of social needs including free web-based information resources about any living being, renovation of museum collections, nature conservation that recognized as a global project, iBOL, as well as resolving global trading problems such as false labeling of species specimens used as food, drug components, entertainment, etc. The main issues of the review are focused on animals and combine four items. (1) A combination of nDNA and mtDNA markers best suits the identification of hybrids and estimation of genetic introgression. (2) The available facts on nDNA and mtDNA diversity seemingly make introgression among many taxa obvious, although it is evident, that introgression may be quite restricted or asymmetric, thus, leaving at least the “source” taxon (taxa) intact. (3) If we consider sexually reproducing species in marine and terrestrial realms introgressed, as it is still evident in many cases, then we should recognize that the BSC, in view of the complete lack of gene flow among species, is inadequate because many zoological species are not biological ones yet. However, vast modern molecular data have proven that sooner or later they definitely become biological species. (4) An investigation into the fish taxa divergence using the BOLD database shows that most gene trees are basically monophyletic and interspecies reticulations are quite rare.

Species

2021 ◽  
pp. 219-238
Author(s):  
Andrew V. Z. Brower ◽  
Randall T. Schuh
Keyword(s):  
Species Concept ◽  
Biological Species ◽  
Species Concepts ◽  
Biological Species Concept ◽  
Character State ◽  
Phylogenetic Species Concept ◽  
Units Of Analysis ◽  
Perceived Reality

This chapter studies the systematists' perspective on species concepts and the role of species in systematics. No matter how sophisticated the tools and methods enhancing the conceptualization of reality may become in the future, systematists will still be constrained by their perceptions. In their more modest, empirical view, systematists embrace their perceived reality and prefer species concepts that incorporate tools for identifying and delimiting species as empirical hypotheses, thereby providing them with efficacious working terminal elements for phylogenetic analysis and classification of more inclusive taxa. It is fortunate that cladists employed the notion of a “phylogenetic” species concept based on diagnosability before more metaphysically inclined authors appropriated the term for concepts founded on monophyly or common ancestors. As noted, Willi Hennig's species concept was a version of the “biological” species concept, and it fell to his followers to develop a species concept that is well suited to cladistic principles. Among the earliest of the post-Hennigian empiricists was American Museum ichthyologist Donn Rosen. Rosen's concept, sometimes called the apomorphic concept because of its requirement that every recognized species must have its own derived character state, accomplished two key advances for systematics: it proposed a cladistic criterion for recognizing species, and it defined species as the minimal units of analysis, as far as taxonomy is concerned, thus setting a lower bound for systematic inquiry.

Discriminating arboviral species

2021 ◽  
Vol 102 (4) ◽  
Author(s):  
Yiyuan Li ◽  
Angela C. O’Donnell ◽  
Howard Ochman
Keyword(s):  
Evolutionary History ◽  
Viral Vectors ◽  
Species Concept ◽  
International Committee ◽  
Biological Species ◽  
Biological Species Concept ◽  
Substantial Variation ◽  
Artificial Boundaries ◽  
Human Infections

Mosquito-borne arboviruses, including a diverse array of alphaviruses and flaviviruses, lead to hundreds of millions of human infections each year. Current methods for species-level classification of arboviruses adhere to guidelines prescribed by the International Committee on Taxonomy of Viruses (ICTV), and generally apply a polyphasic approach that might include information about viral vectors, hosts, geographical distribution, antigenicity, levels of DNA similarity, disease association and/or ecological characteristics. However, there is substantial variation in the criteria used to define viral species, which can lead to the establishment of artificial boundaries between species and inconsistencies when inferring their relatedness, variation and evolutionary history. In this study, we apply a single, uniform principle – that underlying the Biological Species Concept (BSC) – to define biological species of arboviruses based on recombination between genomes. Given that few recombination events have been documented in arboviruses, we investigate the incidence of recombination within and among major arboviral groups using an approach based on the ratio of homoplastic sites (recombinant alleles) to non-homoplastic sites (vertically transmitted alleles). This approach supports many ICTV-designations but also recognizes several cases in which a named species comprises multiple biological species. These findings demonstrate that this metric may be applied to all lifeforms, including viruses, and lead to more consistent and accurate delineation of viral species.

Not just a peep: The evolution of calling in Pseudacris crucifer

2018 ◽  
Author(s):  
Amanda Cicchino
Keyword(s):  
Reproductive Isolation ◽  
Full Range ◽  
Mate Recognition ◽  
Preliminary Evidence ◽  
Biological Species ◽  
Biological Species Concept ◽  
Incipient Species ◽  
Pseudacris Crucifer ◽  
Full Analysis ◽  
American Frog

Reproductive isolation is the hallmark of speciation as defined by the biological species concept. A species that is evolving towards reproductive isolation, but has not reached full isolation, is defined as an incipient species. One mechanism used by incipient species to further drive speciation is the use of mate recognition signals. The spring peeper, Pseudacris crucifer, is a North American frog that can be classified as an incipient species, as previous studies have found 6 distinct mitochondrial lineages within its range. Spring peepers use vocal signals for mate recognition and exhibit a female choice mating system where the males call to attract females. This study investigates the evolution of calling in spring peepers. Using calls from each lineage across the full range of spring peepers, I analyzed 11 different characteristics to determine whether the calls were different, and if so, which characteristics are being selected for. Preliminary evidence suggests that the calls between the lineages are distinct and that certain characteristics of the call are more heavily selected for than others. Full analysis on the data has not been completed at this time. This study will expand the understanding of the evolution of spring peepers, as well as offer insight into the role of mating systems on reproductive isolation.

Steinernema khuongin. sp. (Panagrolaimomorpha, Steinernematidae), a new entomopathogenic nematode species from Florida, USA

2018 ◽  
Vol 93 (2) ◽  
pp. 226-241 ◽  
Author(s):  
S.P. Stock ◽  
R. Campos-Herrera ◽  
F.E. El-Borai ◽  
L.W. Duncan
Keyword(s):  
New Species ◽  
Sequence Data ◽  
Novel Species ◽  
Entomopathogenic Nematode ◽  
Biological Species ◽  
Morphological Data ◽  
Biological Species Concept ◽  
The Novel ◽  
Ecological Data ◽  
Cross Hybridization

AbstractIn this study, molecular (ribosomal sequence data), morphological and cross-hybridization properties were used to identify a newSteinernemasp. from Florida, USA. Molecular and morphological data provided evidence for placing the novel species into Clade V, or the ‘glaseri-group’ ofSteinernemaspp. Within this clade, analysis of sequence data of the rDNA genes, 28S and internal transcribed spacer (ITS), depicted the novel species as a distinctive entity and closely related toS. glaseriandS. cubanum.Additionally, cross-hybridization assays showed that the new species is unable to interbreed with either of the latter two species, reinforcing its uniqueness from a biological species concept standpoint. Key morphological diagnostic characters forS. khuongin. sp. include the mean morphometric features of the third-stage infective juveniles: total body length (average: 1066 μm), tail length (average: 65 μm), location of the excretory pore (average: 80.5 μm) and the values ofc(average: 16.4),D% (average: 60.5),E% (average: 126) andH% (average: 46.6). Additionally, males can be differentiated fromS. glaseriandS. cubanumby the values of several ratios:D% (average: 68),E% (average: 323) and SW% (average: 120). The natural distribution of this species in Florida encompasses both natural areas and citrus groves, primarily in shallow groundwater ecoregions designated as ‘flatwoods’. The morphological, molecular, phylogenetic and ecological data associated with this nematode support its identity as a new species in theS. glaseri-group.

scholarly journals Putting the Biological Species Concept to the Test: Using Mating Networks to Delimit Species

PLoS ONE ◽  
2013 ◽  
Vol 8 (6) ◽  
pp. e68267 ◽  
Author(s):  
Lélia Lagache ◽  
Jean-Benoist Leger ◽  
Jean-Jacques Daudin ◽  
Rémy J. Petit ◽  
Corinne Vacher
Keyword(s):  
Species Concept ◽  
Biological Species ◽  
Biological Species Concept

Fern nothogenera and ×Lepinema, a new hybrid genus between Ellipinema and Lepisorus (Polypodiaceae)

Phytotaxa ◽  
2020 ◽  
Vol 455 (4) ◽  
pp. 262-266
Author(s):  
LIANG ZHANG ◽  
LI-BING ZHANG
Keyword(s):  
Species Concept ◽  
Intergeneric Hybrid ◽  
Molecular Data ◽  
Biological Species ◽  
Biological Species Concept

The biological species concept is not exclusively applicable in many groups of organisms including ferns. Interspecific fern hybrids are not rare: there are 16 intergeneric hybrid genera in ferns confirmed with molecular data. Here we add one more hybrid genus in the tribe Lepisoreae of Polypodiaceae, ×Lepinema, formed via hybridization between parents in two genera: Ellipinema and Lepisorus.

The increasing multiplicity of the species concepts

2005 ◽  
Vol 176 (2) ◽  
pp. 221-225
Author(s):  
Jean Génermont
Keyword(s):  
Species Concept ◽  
Cladistic Analysis ◽  
Biological Species ◽  
Point Of View ◽  
Biological Species Concept ◽  
Phylogenetic Species ◽  
Phylogenetic Species Concept ◽  
Ecological Criteria ◽  
Stem Species ◽  
Definition Of

Abstract In 1980, Henri Tintant advocated the usefulness of the biological species concept in paleontology. At this time, this concept was still accepted by many neontologists, but it was already rather severely criticized by some others. In fact, a lot of new concepts appeared in the course of the following two decades. While a few ones are mere adjustments of the biological concept, for instance taking in account ecological criteria, in such a way that it could be applied to clonal organisms, some others, which were developed in connexion with the cladistic theory of taxonomy, are truly new from a conceptual point of view. The diagnosable version of the phylogenetic species concept is somewhat reminiscent of Simpson’s evolutionary species concept, since it accepts phyletic speciation as well as survival of the stem species after a cladogenetic event. One of its more criticizable features, from a cladistic point of view, is that the species are not necessarilly monophyletic. On another hand, according to the monophyly version of the phylogenetic species concept, species are recognized rather subjectively as monophyletic taxa revealed by some previous cladistic analysis dealing with operational taxonomic units. A consensus on the definition of species cannot be expected, since all concepts related to the biological one are founded on population grouping on the basis of potentially identical evolutionary fates, while those which are related to cladistic taxonomy are exclusively concerned with historical features.

scholarly journals Group selection and the development of the biological species concept

2010 ◽  
Vol 365 (1547) ◽  
pp. 1853-1863 ◽  
Author(s):  
James Mallet
Keyword(s):  
Species Concept ◽  
Biological Species ◽  
Second World War ◽  
Species Level ◽  
Biological Species Concept ◽  
Ernst Mayr ◽  
World War ◽  
Mutualistic Interaction ◽  
Theodosius Dobzhansky ◽  
Second World

The development of what became known as the biological species concept began with a paper by Theodosius Dobzhansky in 1935, and was amplified by a mutualistic interaction between Dobzhansky, Alfred Emerson and Ernst Mayr after the second world war. By the 1950s and early 1960s, these authors had developed an influential concept of species as coadapted genetic complexes at equilibrium. At this time many features of species were seen as group advantages maintained by selection to avoid breakdown of beneficial coadaptation and the ‘gene pool’. Speciation thus seemed difficult. It seemed to require, more so than today, an external deus ex machina , such as allopatry or the founder effect, rather than ordinary within-species processes of natural selection, sexual selection, drift and gene flow. In the mid-1960s, the distinctions between group and individual selection were clarified. Dobzhansky and Mayr both understood the implications, but their views on species changed little. These group selectionist ideas now seem peculiar, and are becoming distinctly less popular today. Few vestiges of group selectionism and species-level adaptationism remain in recent reviews of speciation. One wonders how many of our own cherished views on evolution will seem as odd to future biologists.

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