Articles > Reference > Encyclopedias, Almanacs, Transcripts, and Maps > The Oxford Companion to the Earth excerpts

Encyclopedia entry: species concept

Article from:
The Oxford Companion to the Earth
Author:
Copyright

species concept The definition of a species is a problem that has exercised the minds of many evolutionary biologists. Although we can use the term rather loosely for groups that are visibly distinct because directional selection causes accumulating changes in traits through time, a more objective definition is needed. It is particularly important to know whether species really exist as natural units or whether they are merely divisions that are useful for taxonomists. In biology two meanings of species are recognized, one of which is reproductive and the other morphological or shape-related.

The reproductive species concept states that species are communities of interbreeding organisms. ...

Read all of this article with a FREE trial

Related newspaper, magazine, and journal articles:

Dictionary definition: typological species concept
A Dictionary of Biology;      330 words ...typological species concept The concept of a species as a group whose ... other concepts, notably the biological species concept . These could better account for the many ... agamospecies ). See also phylogenetic species concept .

Dictionary definition: phylogenetic species concept
A Dictionary of Biology;      342 words ...phylogenetic species concept ( PSC ) The concept of a species as an irreducible group whose members are descended ... history. It is less restrictive than the biological species concept , in that breeding between members of different species ...

Dictionary definition: recognition species concept
A Dictionary of Zoology;      282 words ...recognition species concept The concept that a species is characterized by a unique fertilization system (the ... species. This changes the emphasis in the biological species concept from negative (not interbreeding with other species ...

Dictionary definition: biological species concept
A Dictionary of Biology;      365 words ...biological species concept ( BSC ) The concept of a species as a group of populations whose members are capable ... early 20th centuries, largely replacing the typological species concept favoured by pioneer naturalists. Central to the concept ...

Dictionary definition: evolutionary species concept
A Dictionary of Zoology;      259 words ...evolutionary species concept A suggestion made by G. G. Simpson for adapting the biological species concept for a palaeontological context: ‘a species is a lineage with its own evolutionary role and tendencies’.

Dictionary definition: cohesion species concept
A Dictionary of Zoology;      272 words ...cohesion species concept A proposal, made by Alan R. Templeton in 1989, to broaden the biological species concept by including asexual organisms and ... sexually reproducing organisms. A species, in this view, is a population ...

Dictionary definition: internodal species concept
A Dictionary of Zoology;      263 words ...internodal species concept The notion that a species exists between two branching points in a fossil lineage; it is based on a fiction, maintained as a convenience by Willi Hennig , that a species ceases to exist as soon as it branches into two daughter species.

Article: Neuroecology, chemical defense, and the keystone species ...
The Biological Bulletin;  December 1, 2007 ;     700+ words ... ... Similarly, the "keystone" species concept is intrinsically valuable for directing ... community dynamics. A keystone species is one whose impacts on a community ... associated invertebrate and fish species (Estes and Duggins, 1995; Steinberg ...

 
 
Newsweek Harper's Magazine The Washington Post Chicago Tribune Crain's Chicago Business PRNewswire Pediatric News The Nation Advertising Age The Economist (US) A FREE trial gives you access to over 80 million articles! Access over 6,500 publications with a FREE trial!

Find articles, research, and archives