speciation

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spe·ci·a·tion

(spē'shē-ā'shŭn),
The evolutionary process by which diverse species of animals or plants are formed from a common ancestral stock.

speciation

/spe·ci·a·tion/ (spe″se-a´shun) the evolutionary formation of new species.

speciation

(spē′shē-ā′shən, -sē-)
n.
The formation of new biological species through the process of evolution.

spe′ci·ate′ v.
spe′ci·a′tion·al adj.

spe·ci·a·tion

(spē'shē-ā'shŭn)
The evolutionary process by which diverse species of animals or plants are formed from a common ancestral stock.

speciation

the process by which new species are formed. Speciation occurs when gene flow has effectively ceased between populations where it previously existed and is brought about by ISOLATING MECHANISMS.see GEOGRAPHICAL ISOLATION.
References in periodicals archive ?
Mr Bell said he fears that diseases which humans are immune to at the moment could be passed on through breaking the species barrier.
Although the disease will continue to break the species barrier, the ultimate goal of all disease surveillance, research, and development is the avoidance of a major pandemic of H5N1 avian influenza.
The varying potential for avian-to-human transmission depending on the virus strain highlights the need for permanent serosurveillance studies in animals and in humans, both during outbreaks of highly pathogenic avian influenza and when less pathogenic strains are circulating, in order to gain more knowledge about the crossing of the species barrier, the authors said.
But just how prevalent TSEs may become is related to the resistance to infection across species--the so-called species barrier.
Experts at a Royal Society conference in London cite the risk that new diseases will "learn" to jump the species barrier.
But disturbing news arose last month when Chinese researchers discovered that the virus has now appeared in pigs, revealing its ability to jump yet another species barrier.
Some people may express a fear, distaste, revulsion, or general anxiety about the "unnatural" mixing of species--about creating chimeras, about altering the telos of species (so as to interfere with a fish's "fishness," for example), about crossing the species barrier, and about the intertwining of human and animal genes.
Acts of abuse are about power and control regardless of the species of the victim, and crossing the species barrier is but a small step.
Although these strains of flu are different than the one in Asia and pose no risk of crossing the species barrier to humans, in Delaware, more than 80,000 chickens were slaughtered and many farms were quarantined as a precaution to protect the rest of the poultry flocks.
But even after Great Britain announced in March 1996 that Mad Cow could leap the species barrier and infect humans (killing about 140 people there, to date), U.
In a somewhat alarming development, during the past 6 years, influenza A has jumped the species barrier, with infection passing directly from poultry to humans, as exemplified by the 1997 experience in Hong Kong with influenza A H5N 1, and more recently in the Netherlands with influenza A H7N7.