Variation of Sicilian pond turtles, Emys trinacris – What makes a species cryptic?

2006 ◽  
Vol 27 (4) ◽  
pp. 513-529 ◽  
Author(s):  
Uwe Fritz ◽  
Stefania D'Angelo ◽  
Maria Grazia Pennisi ◽  
Mario Lo Valvo
Keyword(s):  
Cryptic Species ◽  
Species Concept ◽  
Biological Species ◽  
Morphological Data ◽  
Similar Species ◽  
Last Common Ancestor ◽  
Species Determination ◽  
Phylogenetic Species Concept ◽  
The North ◽  
Emys Trinacris

Abstract Variation of the Sicilian pond turtle, Emys trinacris, is described, based on morphological data of more than 200 adult and immature turtles and mtDNA sequences of 31 new known-locality specimens. Emys trinacris is morphologically more variable than thought before. There exist pronounced population-specific differences. Adults are barely distinguishable from Emys orbicularis galloitalica. Hatchlings of E. trinacris are, however, significantly different patterned, allowing immediate species determination. Moreover, hatchlings of E. trinacris seem to be on average smaller and lighter than in E. orbicularis. This could be related with different reproductive strategies. Coloration polymorphism of adult Sicilian pond turtles comprises fair part of variation known in E. orbicularis. Thus, adult E. trinacris might have preserved the whole array of variation of the last common ancestor with E. orbicularis. We hypothesize that similarity of certain southern E. orbicularis subspecies and E. trinacris on one hand and pronounced differences in size, coloration and pattern of northern E. orbicularis subspecies on the other result from stabilising selection in the north. While dark coloration and large body-size seem to be beneficial in the north, light coloration and small size could be simply not disadvantageous in the south, allowing coloration polymorphisms in E. trinacris and southern E. orbicularis subspecies. Further, the term 'cryptic species' and its meaning in regard to species concepts and bar-coding is discussed. It is concluded that species delineation based on mtDNA barcoding requires application of a Phylogenetic Species Concept. Under the Biological Species Concept, animal mtDNA is not always an ideal tool for delineating species boundaries because taxa with monophyletic mitochondrial gene trees are neither necessarily genetically isolated nor must represent the same Biological Species. Cryptic species are nothing special in nature because difficulties with their identification are due to deficits in cognitive abilities of man. This is illustrated by the fact that distinct live stages of 'cryptic species' may differ to various degrees from similar species, as is the case in hatchlings and adults of E. trinacris and E. o. galloitalica.

A revision of Calamus (Arecaceae, Calamoideae, Calameae, Calaminae)

Phytotaxa ◽  
2020 ◽  
Vol 445 (1) ◽  
pp. 1-656
Author(s):  
ANDREW HENDERSON
Keyword(s):  
New Species ◽  
Species Concept ◽  
Morphological Data ◽  
Herbarium Specimens ◽  
Phylogenetic Species ◽  
Type Specimens ◽  
Phylogenetic Species Concept ◽  
Distribution Maps ◽  
Qualitative Variables ◽  
Geographic Distributions

A revision of Calamus was carried out based on morphological data. Eight thousand, six hundred and thirty-three herbarium specimens were examined and scored for 14 quantitative and 157 qualitative variables. Application of the Phylogenetic Species Concept to 516 preliminary species of Calamus resulted in recognition of 411 phylogenetic species. Of these, 38 are recognized as new (C. barisanensis, C. brevissimus, C. brunneus, C. calciphilus, C. densifloropsis, C. disjunctus, C. divergens, C. exiguus, C. furvus, C. gaharuensis, C. goramensis, C. heteracanthopsis, C. hosensis, C. impressus, C. insolitus, C. insularis, C. johanis, C. kinabaluensis, C. kubahensis, C. latus, C. lengguanii, C. lobatus, C. notabilis, C. obiensis, C. oresbiopsis, C. oxleyoides, C. pahangensis, C. powlingii, C. saltuensis, C. seropakensis, C. spinosus, C. sulawesiensis, C. tambingensis, C. tapanensis, C. trigynus, C. vinaceus, C. viridis, C. wedaensis). Analysis of quantitative variables and geographic distributions resulted in the division of 11 species into 36 subspecies. Eight species were considered to be ochlospecies (C. erioacanthus, C. inermis, C. javensis, C. melanochaetes, C. micranthus, C. moseleyanus, C. plicatus, C. siphonospathus). Nomenclature, descriptions, and distribution maps are provided for all species. Images of the type specimens of all new species are provided as well as images of most qualitative variables. One hundred and forty–three species are illustrated with images from living plants.

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 Predictors of Taxonomic Inflation and its Role in Primate Conservation

2021 ◽  
Author(s):  
Maria J.A. Creighton ◽  
Alice Q. Luo ◽  
Simon M. Reader ◽  
Arne Ø. Mooers
Keyword(s):  
Perceived Risk ◽  
Species Concept ◽  
Research Effort ◽  
Biological Species ◽  
Primate Species ◽  
Biological Species Concept ◽  
Primate Conservation ◽  
Phylogenetic Species Concept ◽  
Initial Application ◽  
Positive Message

ABSTRACTSpecies are the main unit used to measure biodiversity, but different preferred diagnostic criteria can lead to very different delineations. For instance, named primate species have more than doubled since 1982. Such increases have been termed “taxonomic inflation” and have been attributed to the widespread adoption of the ‘phylogenetic species concept’ (PSC) in preference to the previously popular ‘biological species concept’ (BSC). Criticisms of the PSC have suggested taxonomic inflation may be biased toward particular taxa and have unfavourable consequences for conservation. Here, we explore predictors of taxonomic inflation across primate taxa since the initial application of the PSC nearly 40 years ago. We do not find evidence that diversification rate, the rate of lineage formation over evolutionary time, is linked to inflation, contrary to expectations if the PSC identifies incipient species. We also do not find evidence of research effort in fields where work has been suggested to motivate splitting being associated with increases in species numbers among genera. To test the suggestion that splitting groups is likely to increase their perceived risk of extinction, we test whether genera that have undergone more splitting have also observed a greater increase in their proportion of threatened species since the introduction of the PSC. We find no cohesive signal of inflation leading to higher threat probabilities across primate genera. Overall, this analysis sends a positive message that threat statuses of primate species are not being overwhelmingly affected by splitting in line with what has recently been reported for birds. Regardless, we echo warnings that it is unwise for conservation to be reliant on taxonomic stability. Species (however defined) are not independent from one another, thus, monitoring and managing them as such may not meet the overarching goal of conserving biodiversity.

Species limits in Pteruthius (Aves: Corvida) shrike-babblers: a comparison between the Biological and Phylogenetic Species Concepts

Zootaxa ◽  
2009 ◽  
Vol 2301 (1) ◽  
pp. 29-54 ◽  
Author(s):  
FRANK E. RHEINDT ◽  
JAMES A. EATON
Keyword(s):  
Species Concept ◽  
Molecular Data ◽  
Biological Species ◽  
Species Concepts ◽  
Biological Species Concept ◽  
Phylogenetic Species ◽  
Species Status ◽  
Phylogenetic Species Concept ◽  
Sampling Regime ◽  
Morphological And Molecular Data

The question of how to define a species continues to divide biologists. Meanwhile, the application of different species concepts has led to disparate taxonomic treatments that confound conservationists and other biologists. The most widely followed guidelines to species designation in avian and other vertebrate taxonomy are Ernst Mayr’s Biological Species Concept (BSC) and Joel Cracraft’s version of the Phylogenetic Species Concept (PSC). Although the BSC is considered to be more conservative in its assignment of species status, there is a lack of research demonstrating differences in taxonomic treatment between the BSC and the PSC with reference to a multi-taxon multi-trait study system. We examined the case of five traditionally recognized species of shrike-babbler (Pteruthius) that have recently been divided into 19 species under the PSC. Re-analyzing previous morphological and molecular data and adding new vocal data, we propose a BSC classification of 9 species. However, taking into consideration geographic gaps in the sampling regime, we contend that additional data will likely reduce discrepancies between the total numbers of species designated under the PSC and BSC. The current PSC species total is a likely overestimate owing to species diagnosis based on characters that erroneously appear to be unique to a taxon at low sample size. The current BSC species total as here proposed is a likely underestimate on account of the conservative designation of taxa as subspecies in equivocal cases, e.g. where BSC species status is potentially warranted but may be masked by insufficient data.

Species and speciation.

2022 ◽  
pp. 7-8
Author(s):  
Richard A. I. Drew ◽  
Meredith C. Romig
Keyword(s):  
New Species ◽  
Natural Selection ◽  
Dna Sequences ◽  
Species Concept ◽  
Natural Habitat ◽  
Biological Species ◽  
Biological Species Concept ◽  
Similar Species ◽  
Host Fruit ◽  
Morphological Species

Abstract This chapter discusses two species models, which are diametrically opposed. The first, often called the 'biological species concept', defines species in terms of 'reproductive isolation', convinced that species arise when subsets of a population are split off and remain geographically isolated over evolutionary time. If and when such new species are reunited with their founder population, interbreeding does not occur, or if it does, infertile progeny result. Hence, from the biological species concept, natural selection is a primary agent of change and directly selects for new species. In this sense, species are the direct products of natural selection and they are therefore 'adaptive devices'. When applying this species concept, it has been impossible to separate some sibling species of fruit flies in the genus Bactrocera where distinct morphological species can be similar in molecular analyses of certain DNA sequences, while similar species morphologically are distinct in the same molecular characters. A radically different model, the 'recognition concept of species', relies heavily on a knowledge of species ecology and behaviour, particularly in their natural habitat. The principal points in this concept are given. In contrast to the now-outdated biological species concept that leads one to depend on laboratory-based research to define species, the recognition concept requires workers to undertake extensive field research in the habitat of the taxon under investigation. In translating this approach to research in the insect family Tephritidae, particularly the Dacinae, some 35 years of field surveys have been undertaken throughout the Indian subcontinent, South-east Asia and the South Pacific region. These surveys included trapping using male lure traps and host fruit collections of commercial/edible fruits. The results of this work have included the provision of specimens of almost all known species for morphological descriptions (c.800 species), material for male pheromone chemistry, and data on host fruit relationships and biogeographical studies.

scholarly journals Geographic Variation in the Wingtip Patterns of Black-Legged Kittiwakes

The Condor ◽  
2002 ◽  
Vol 104 (3) ◽  
pp. 687-693
Author(s):  
John W. Chardine
Keyword(s):  
Geographic Variation ◽  
Barents Sea ◽  
Species Concept ◽  
Biological Species ◽  
Biological Species Concept ◽  
Genotypic Differences ◽  
Phylogenetic Species Concept ◽  
Rissa Tridactyla ◽  
The Pacific ◽  
Circumpolar Arctic

Abstract This paper reports geographic variation in wingtip patterns of Black-legged Kittiwakes (Rissa tridactyla) from the circumpolar Arctic. The amount of black in the wingtip increased and the amount of white decreased from Arctic Canada–west Greenland, counterclockwise to the Pacific. Differences were greatest between Pacific and Atlantic, but were also apparent within the Atlantic sample. Patterns of variation were not clinal. Known levels of philopatry in kittiwakes would tend to maintain both phenotypic and genotypic differences between regions, but the similarity of birds from Newfoundland, British Isles, and Barents Sea suggests some degree of dispersal over this wide area. Wingtip pattern data support continued separation of Pacific and Atlantic kittiwakes into two subspecies under the biological species concept. Under the phylogenetic species concept, Pacific and Atlantic Black-legged Kittiwakes may represent two species. Variación Geográfica en los Patrones de Coloración de la Punta del Ala de Rissa tridactyla Resumen. Este trabajo presenta la variación geográfica existente en los patrones de coloración de la punta del ala de Rissa tridactyla en el área circumpolar ártica. La cantidad de negro en la punta del ala incrementó y la cantidad de blanco disminuyó desde el ártico canadiense y el oeste de Groenlandia en sentido contrario a las agujas del reloj hacia el Pacífico. Las mayores diferencias se registraron entre el Pacífico y el Atlántico, pero también fueron evidentes en la muestra del Atlántico. Los patrones de variación no fueron graduales. Los niveles conocidos de filopatría en R. tridactyla tenderían a mantener las diferencias tanto fenotípicas como genotípicas entre regiones, pero la similitud de las aves de Newfoundland, las Islas Británicas y el Mar de Barents sugiere algún grado de dispersión a través de esta extensa área. Considerando el concepto biológico de especie, los datos sobre los patrones de la punta del ala apoyan la separación de las aves del Pacífico y del Atlántico en dos subespecies. Considerando el concepto filogenético de especie, los individuos de R. tridactyla del Pacífico y del Atlántico pueden pertenecer a dos especies diferentes.

A revision of the Trimeresurus puniceus-complex (Serpentes: Viperidae: Crotalinae) based on morphological and molecular data

Zootaxa ◽  
2006 ◽  
Vol 1293 (1) ◽  
pp. 1 ◽  
Author(s):  
PATRICK DAVID ◽  
GERNOT VOGEL ◽  
S. P. VIJAYAKUMAR ◽  
NICOLAS VIDAL
Keyword(s):  
Species Concept ◽  
Distinct Species ◽  
Morphological Characters ◽  
Molecular Data ◽  
Biological Species ◽  
Valid Species ◽  
Biological Species Concept ◽  
Phylogenetic Species Concept ◽  
Morphological And Molecular Data ◽  
A New Species

The brown Asian pitvipers of the genus Trimeresurus related to Trimeresurus puniceus (informal Trimeresurus puniceus-complex) are revised on the basis of morphological and molecular analyses. Variation in morphological characters were investigated among 119 specimens from 62 populations of the whole range of the pitvipers currently known as Trimeresurus puniceus (Boie, 1827), Trimeresurus borneensis (Peters, 1872) and Trimeresurus brongersmai Hoge, 1969. Molecular and morphological analyses clearly differentiate two groups of taxa, referrable to the informal Trimeresurus puniceus-group and Trimeresurus borneensis-group, and confirm the distinct specific status of T. puniceus and T. borneensis. Morphological univariate and multivariate analyses differentiate six clusters of populations that are morphologically diagnosable, of which five are here considered to represent independent lineages and one is placed incertae sedis pending the availability of further specimens. These clusters are considered to be distinct species following the Biological Species Concept and the Phylogenetic Species Concept. One of them is described as a new species, Trimeresurus andalasensis spec. nov. (T. borneensis-group), which includes populations from northern Sumatra. Trimeresurus wiroti Trutnau, 1981 is revalidated to accommodate populations from Thailand and West Malaysia. Trimeresurus borneensis is here considered endemic to Borneo. Trimeresurus puniceus is known from Java and from South Sumatra, but the taxonomy of this species in Sumatra is left unresolved. Also left unresolved is the taxonomic position of specimens from western Sumatra and the Mentawai Archipelago, and from the Natuna Islands and Anamba Islands. Although belonging to the T. puniceus-group, they show some differences to other specimens of the group. They are not referred to any taxon pending the collection of additional specimens. Lastly, Trimeresurus brongersmai is confirmed as a valid species from the Mentawai Archipelago. A key to these taxa is provided.

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.

scholarly journals An alternative species taxonomy of the birds of Mexico

2004 ◽  
Vol 4 (2) ◽  
pp. 1-32 ◽  
Author(s):  
Adolfo G. Navarro-Sigüenza ◽  
A. Townsend Peterson
Keyword(s):  
Species Concept ◽  
Bird Species ◽  
Biological Species ◽  
Species Concepts ◽  
Biological Species Concept ◽  
Phylogenetic Species ◽  
Phylogenetic Species Concept ◽  
Alternative Species ◽  
Species Taxonomy

Extensive debate has surrounded the application of alternative species concepts in Ornithology. The biological species concept (BSC) and phylogenetic species concept (PSC) have typically been set in opposition, with extensive debate on the relative merits of each. An alternative is the evolutionary species concept (ESC), which offers a perspective similar to that of the PSC, yet with several significant differences. To date, no major avifauna has been examined and compared among taxonomic viewpoints. Herein, we develop an alternative phylogenetic/evolutionary species taxonomy to the current BSC treatment for the more than 1000 bird species of Mexico. A total of 135 biological species was divided to produce a total of 323 phylogenetic/evolutionary species, 122 of which represent “new” endemic forms in Mexico.

scholarly journals Conservation and species lists: taxonomic neglect promotes the extinction of endemic birds, as exemplified by taxa from eastern Atlantic islands

1996 ◽  
Vol 6 (2) ◽  
pp. 181-196 ◽  
Author(s):  
C. J. Hazevoet
Keyword(s):  
Species Concept ◽  
Conservation Status ◽  
Morphological Differentiation ◽  
Taxonomic Status ◽  
Biological Species ◽  
Hierarchical Level ◽  
Conservation Priorities ◽  
Biological Species Concept ◽  
Clinal Variation ◽  
Phylogenetic Species Concept

SummaryWhen formulating conservation priorities, conservation biologists often rely on published lists of species-level taxa. This paper discusses the nature and taxonomic status of “species” and “subspecies” and different ways of defining “species”. Species are here taken to be terminal and evolutionarily independent units which are qualitatively diagnosable and reproductively cohesive; genealogical biodiversity is thus taken for what it is in the first place, namely the observable result of evolutionary history, an approach which has become known as the phylogenetic species concept (PSC). In contrast to the widely applied Mayrian or “biological” species concept (BSC), no inferences are made about how the degree of morphological differentiation of allopatric but seemingly closely related taxa translates in the absence or presence of reproductive isolation. Many diagnosably distinct endemic island taxa have traditionally been treated as “subspecies” of widespread “polytypic biological” species. At the same time, the “subspecies” category is also used to name arbitrarily delimited sections of intraspecific clinal variation. Thus, the “subspecies” category subjects entirely different evolutionary phenomena to the same hierarchical level through the use of trinomials. Nevertheless, and despite the discrepancy in ontological status among its contents, “subspecies” are usually considered to be of lower evolutionary and/or conservation status than “species” and this has resulted in low conservation priorities allotted to diagnosably distinct island endemics, many of which have traditionally been considered to be “merely Mayrian subspecies”. This has been recognized by some authorities who, because of the threatened status of certain island taxa, advocated treating them binomially in order to generate appropriate conservation measures to save them from extinction, without however justifying their action by any sort of phylogenetic reasoning. Although well intended and sometimes quite successful as regards the follow-up by conservationists, this demonstrates the arbitrary manner in which “species” can be defined under the BSC. Some examples of endemic taxa from eastern Atlantic islands are discussed, demonstrating the way “list thinking” and the lack of phylogenetic reasoning among conservationists translates into the presence or absence of conservation actions. Some of the criticisms of the PSC by adherents of the BSC are discussed. It is advocated that conservationists replace “list thinking” with “lineage thinking”.

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