scholarly journals A combined analysis of morphological traits, chloroplast and nuclear DNA sequences within Santiria trimera (Burseraceae) suggests several species following the Biological Species Concept

2010 ◽  
Vol 143 (2) ◽  
pp. 160-169 ◽  
Author(s):  
K. Guillaume Koffi ◽  
Myriam Heuertz ◽  
Charles Doumenge ◽  
Jean Michel Onana ◽  
Frederick Gavory ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Morphological Traits ◽  
Nuclear Dna ◽  
Species Concept ◽  
Biological Species ◽  
Biological Species Concept ◽  
Combined Analysis

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 In contrast to the now-outdated biological species concept that leads one to depend on laboratory-based research to define species, the recognition concept requires workers to undertake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 Combining morphology and population genetic analysis uncover species delimitation in the widespread African tree genus Santiria (Burseraceae)

Phytotaxa ◽  
2017 ◽  
Vol 321 (2) ◽  
pp. 166 ◽  
Author(s):  
DAVY U. IKABANGA ◽  
TARIQ STÉVART ◽  
K. GUILLAUME KOFFI ◽  
FRANCK KAMENI MONTHÉ ◽  
ELIE C. NZIGOU DOUBINDOU ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Species Delimitation ◽  
Nuclear Dna ◽  
Central Africa ◽  
Taxonomic Revision ◽  
Biological Species ◽  
Morphological Data ◽  
Biological Species Concept ◽  
Population Genetic Analysis ◽  
Genetic Clusters

Taxonomic classification based on morphology alone can prove difficult. This is the case of the polymorphic forest tree species Santiria trimera in Africa, whose classification has remained controversial for over a century. Studies combining chloroplast and nuclear DNA sequences show the existence of several phylogenetic clades in this taxon, with some occurring in sympatry in western Central Africa suggesting the existence of at least two species. By combining genetic and morphological markers, we aim to assess the species delimitation in the Santiria species complex. Morphological trait (trunk, leaflet, flower and fruit characteristics) analysis using 223 standing individuals and 103 herbarium samples were combined with genetic analyses using 479 individuals genotyped at eight microsatellite markers. Genetic clusters were identified using Bayesian assignment in order to delimit species following the Biological Species Concept and to identify distinctive characters from morphometric analyses in retrospect. Three genetic clusters were identified and found to occur in sympatry. The type of inflorescence and the colour of unripe fruit were the most discriminant morphological traits among those genetic clusters, while many quantitative traits showed overlapping distributions between genetic clusters and explain the difficulty encountered by previous botanists to resolve the taxonomy of Santiria. The combination of genetic and morphological data suggests the presence of three species within the taxon Santiria trimera from western Central Africa. This work should guide a taxonomic revision within the genus Santiria in Africa.

scholarly journals Taxonomy and Species Delimitation in Cyanobacteria

2021 ◽  
Author(s):  
Alessio Papini ◽  
Sara Falsini ◽  
Tiruha Habte Karssa
Keyword(s):  
Dna Sequences ◽  
Species Delimitation ◽  
Species Concept ◽  
Cell Structure ◽  
Ultrastructural Level ◽  
Biological Species ◽  
Botanical Nomenclature ◽  
Biological Species Concept ◽  
Theoretical Point ◽  
Main Concept

Cyanobacteria are prokaryotes whose taxonomy follows the same rules of a code (the International Botanical Nomenclature Code, IBNC) built for eukaryotic photosynthetic organisms. Hence, names of cyanobacteria follow the same rules and are assigned to biological entities (species) that should correspond to eukaryotic species. The main difficulty in the current situation is that the species concept in eukaryotes is based theoretically mainly on the biological species concept, that is centered on genetic exchange through sexual reproduction or lack of them. However, as shown, this difference is important from a theoretical point of view, but also in eukaryotes, the boundaries between different species are very rarely checked experimentally by direct observation of sexual barriers and hybridization events. The main concept for species delimitation is hence that related to morphology and, more recently and always in relation to morphology, DNA sequences. The introduction of distances obtained from matrixes of aligned sequences in the framework of a barcoding project provides a quantitative interpretation of species delimitation in relation to genetic distance that can be used both in eukaryotes and prokaryotes. However, the introduction of quantitative criteria needs the definition of distance thresholds to identify the boundaries between different species and, for doing that, it is necessary to test the distance thresholds in models of traditionally defined and recognized species. An alternative approach may be the comparison of the molecular distance (quantitative approach) to data about the capability of strains/species to exchange genetic information. Unfortunately data about this last question is still scarce. The adoption of molecular criteria to check species boundaries based on morphological characters has proved particularly challenging in cyanobacteria: a known example is provided. In conclusion, the only possible approach appears to be the association of molecular data to the increase of available data about the cell structure and the variation thereof in different physiological situations, particularly at the ultrastructural level. A further necessity is the check of the typus for a large number of cyanobacteria species, often based on old basionyms. In many of these cases the typus is often a drawing and more rarely a herbarium specimen or a microscope slide. In many cases an epitypification or a neotypification appears to be necessary.

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.

scholarly journals A Molecular Phylogeny of the Dove Genus Zenaida: Mitochondrial and Nuclear DNA Sequences

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 864-870 ◽  
Author(s):  
Kevin P. Johnson ◽  
Dale H. Clayton
Keyword(s):  
Molecular Phylogeny ◽  
Cytochrome B ◽  
Dna Sequences ◽  
Nuclear Dna ◽  
Bootstrap Support ◽  
Zenaida Asiatica ◽  
Species Status ◽  
Combined Analysis ◽  
Significant Conflict

AbstractWe reconstructed a phylogeny for the seven species of doves in the genus Zenaida on the basis of a combined analysis of mitochondrial (ND2 and cytochrome b) and nuclear (fibrinogen intron 7) DNA sequences. This phylogeny, which is completely resolved, is well supported with all nodes showing greater than 50% bootstrap support. There was no significant conflict between trees based on each gene independently, although trees produced from fibrinogen intron 7 did not resolve relationships among five of the Zenaida species. The species status of Z. graysoni, as well as that of Z. meloda, is suggested based on their divergence from sister taxa (about 1% and 4%, respectively) and other differences. Zenaida can be divided into two major groups: Zenaida asiatica and Z. meloda versus Z. aurita, Z. galapagoensis, Z. auriculata, Z. graysoni, and Z. macroura.

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.

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