Cyto-Genetics and the Species Concept

Nepenthes is a genus of 130-160 species, almost half of which were described after 2001. The recent, rapid increase in species descriptions has been driven by application of a less rigorous species concept by botanists, taxonomic inflation, and discoveries of new taxa during explorations of remote parts of Southeast Asia. Many recently published species descriptions of Nepenthes are based entirely upon qualitative morphological information and are not supported by adequate research. Accordingly, the status of many Nepenthes taxa is contested. Evolution within the genus is not well understood, because nuclear and maternally inherited plastid genomes cannot resolve relationships between many species, particularly those that evolved recently through introgression or reticulate evolution. Improvement in our understanding of the systematics and evolution of Nepenthes requires the adoption of ‘best practice’ collection and preservation methods, and the application of quantitative analytical methods for morphological, genetic, and ecological information.

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The future of research with carnivorous plants

10.1093/oso/9780198779841.003.0029 ◽

2018 ◽

Author(s):

Aaron M. Ellison ◽

Lubomír Adamec

Keyword(s):

Natural Selection ◽

Population Biology ◽

Field Experiments ◽

Evolutionary Dynamics ◽

Species Concept ◽

Intraspecific Variability ◽

Carnivorous Plants ◽

Assisted Migration ◽

Transcriptomic Data ◽

Phylogenetic Framework

The material presented in the chapters of Carnivorous Plants: Physiology, Ecology, and Evolution together provide a suite of common themes that could provide a framework for increasing progress in understanding carnivorous plants. All speciose genera would benefit from more robust, intra-generic classifications in a phylogenetic framework that uses a unified species concept. As more genomic, proteomic, and transcriptomic data accrue, new insights will emerge regarding trap biochemistry and regulation; interactions with commensals; and the importance of intraspecific variability on which natural selection works. Continued elaboration of field experiments will provide new insights into basic physiology; population biology; plant-animal and plant-microbe relationships; and evolutionary dynamics, all of which will aid conservation efforts and contribute to discussions of assisted migration as the climate continues to change.

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The Species Concept

Evolution ◽

10.2307/2405675 ◽

1951 ◽

Vol 5 (4) ◽

pp. 285 ◽

Cited By ~ 114

Author(s):

George Gaylord Simpson

Keyword(s):

Species Concept

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Rubus gizellae (Rosaceae), a bramble species from southeastern Europe—identification history, neotypification, and taxonomic notes

Phytotaxa ◽

10.11646/phytotaxa.167.1.12 ◽

2014 ◽

Vol 167 (1) ◽

pp. 141

Author(s):

GERGELY KIRÁLY ◽

ZOLTÁN BARINA ◽

BOHUMIL TRÁVNÍČEK

Keyword(s):

Breeding System ◽

Species Concept ◽

Critical Group ◽

Type Material ◽

Southeastern Europe ◽

Modern Species ◽

Poor Understanding

The genus Rubus Linnaeus (1753: 492) with nearly 700 species in Europe (Kurtto et al. 2010) constitutes an extraordinarily taxonomically critical group within the Rosaceae (Rosoideae). The richness of morphotypes combined with a poor understanding of the breeding system of apomictic brambles has resulted in the description of thousands of entities. Lack of taxonomic standards and an overwhelming number of scientific names has caused nomenclatorial chaos, which mainly has been resolved by the modern species concept developed in Europe in the late 1900s (“Weberian reform”, Weber 1999; Haveman & de Ronde 2012). However, the review of older names is an extended process and re-evaluation of names has often failed due to lack of type material.

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Discriminating arboviral species

Journal of General Virology ◽

10.1099/jgv.0.001572 ◽

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.

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Taxonomic Re-Examination of the Late Cretaceous Planktonic Foraminiferal Species Archaeoglobigerina Cretacea (d'Orbigny, 1840) and Constraints on Its Morphologic Variability and Stratigraphic Distribution in One of The Type Localities (Kent, SE England)

The Journal of Foraminiferal Research ◽

10.2113/gsjfr.51.1.46 ◽

2021 ◽

Vol 51 (1) ◽

pp. 46-63

Author(s):

Francesca Falzoni ◽

Annachiara Bartolini

Keyword(s):

Late Cretaceous ◽

Species Concept ◽

Morphological Features ◽

Single Individual ◽

Type Specimens ◽

Foraminiferal Species ◽

Morphological Differences ◽

Lower Campanian ◽

Original Drawings

ABSTRACT Distinctive and taxonomically relevant morphological differences exist between the original drawings of Archaeoglobigerina cretacea illustrated by d'Orbigny (1840) and the lectotype designated by Banner & Blow (1960), particularly regarding the equatorial periphery, which is rounded in the former and double-keeled in the latter specimen. Such differences would suggest that they are not conspecific, but this hypothesis cannot be easily tested because d'Orbigny's drawings likely represent a synthesis of observations on several specimens rather than a single individual and the slide intended to contain the lectotype is empty. In this study, we have re-examined the A. cretacea type specimens deposited in the d'Orbigny collection at the Muséum National d'Histoire Naturelle in Paris and samples from one of the type localities (Kent, SE England) with the aim to reconstruct d'Orbigny's species concept, clarify its morphological features, and better constrain its stratigraphic distribution. Our study suggests that d'Orbigny's concept for A. cretacea was broad and included unkeeled as well as double-keeled morphotypes. However, assemblages from Kent yield common and large-sized specimens conspecific with the lectotype in the middle Santonian-lower Campanian, while morphotypes resembling the drawings of d'Orbigny are absent. Accordingly, five topotype specimens from the lower Campanian of Kent are herein illustrated in order to stabilize the species concept adopted over the last 60 years on the basis of the lectotype drawing and description. All topotypes possess a wide imperforate peripheral band and a moderately to weakly developed double-keeled periphery. Finally, the description of A. cretacea is emended to exclude specimens that do not possess an imperforate peripheral band and to include those that show curved and weakly beaded spiral sutures.

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The speciation continuum and species relations between populations: in search of agreement between the theory and practice of systematics

Species in Biology - Novitates Theriologicae ◽

10.53452/nt1226 ◽

2021 ◽

pp. 173-179

Author(s):

Oleksandr Zinenko

Keyword(s):

Reproductive Isolation ◽

Species Concept ◽

Climatic Conditions ◽

Point Of View ◽

Theory And Practice ◽

Hybrid Origin ◽

Isolated Populations ◽

As Species ◽

Mitochondrial Cytochrome B ◽

Traditional Taxonomy

From an evolutionary point of view, the achievement of species status by a group of populations is an ongoing process (except for rare cases of instantaneous speciation), during which isolated populations acquire traits and adaptations that minimize gene flow between them. However, depending on the group, the ways and timing of the gaining of reproductive isolation may be different. In such a complex group for systematics as small vipers (genus Vipera, subgenus Pelias), there are a number of problematic situations for species delimitation: the ability to form hybrids and hybrid populations between species, adaptive hybridization and hybrid speciation, and possible traces of reversed speciation, which indicate that complete and irreversible reproductive isolation may not be achieved at all. The effectiveness of reproductive isolation largely depends on external factors, mostly related to the range spatial structure, ecology of species in areas of sympatry, as well as climatic conditions and their changes, landscape dynamics, etc. The only species concept that allows to describe new species in the absence of reproductive isolation, recognizes the possibility of hybrid and reverse speciation — de Queiroz unified species concept — is practically unsuitable due to the need to consider as species a large number of isolated populations. Therefore, the solution is a conservative approach in practical taxonomy, which takes into account as a species criterion the ecological divergence of species, the possibility of their sympatric existence, which is usually achieved at 5% divergence of the mitochondrial cytochrome b gene. Stabilized hybrid populations occupying distinct ecological niche different from those of parental species also deserve recognition as species of hybrid origin. Not only species deserves to be protected, but also a distinguishable and diverged group of populations — Evolutionary Significant Unit (ESU) or subspecies in traditional taxonomy.

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