extinction


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Related to extinction: Mass extinction, Extinction of Species

extinction

 [eks-ting´shun]
in psychology, the disappearance of a conditioned response as a result of its not being reinforced; also, the process by which the disappearance is accomplished. See also conditioning.

ex·tinc·tion

(eks-tingk'shŭn),
1. In behavior modification or in classical or operant conditioning, a progressive decrease in the frequency of a response that is not positively reinforced; the withdrawal of reinforcers known to maintain an undesirable behavior.
2. Synonym(s): absorbance
[L. extinguo, to quench]

extinction

/ex·tinc·tion/ (eks-tink´shun) in psychology, the disappearance of a conditioned response as a result of nonreinforcement; also, the process by which the disappearance is accomplished.

extinction

(ĭk-stĭngk′shən)
n.
1.
a. The act of extinguishing: The extinction of the fire took several hours.
b. The condition of being extinguished: mourned the extinction of her dreams.
2. The fact of being extinct or the process of becoming extinct: the extinction of the passenger pigeon; languages that are in danger of extinction.
3. Psychology A reduction or a loss in the strength or rate of a conditioned response when the unconditioned stimulus or reinforcement is withheld.
4. Physiology A gradual decrease in the excitability of a nerve to a previously adequate stimulus, usually resulting in total loss of excitability.

extinction

[iksting′shən]
a state of being lost or destroyed.

extinction

Psychiatry A facet of operant–classical conditioning, in which the conditioned response is weakened and eventually disappears by nonreinforcement. See Operant conditioning, Respondent conditioning, Sensory extinction.

ex·tinc·tion

(eks-tingk'shŭn)
1. In behavior modification or classical or operant conditioning, a progressive decrease in the frequency of a response that is not positively reinforced.
See: conditioning
2. Synonym(s): absorbance.
[L. extinguo, to quench]

extinction

  1. the act of making EXTINCT or the state of being extinct.
  2. the elimination of an allele of a gene in a population, due to RANDOM GENETIC DRIFT or to adverse SELECTION pressures.
  3. any periodical, catastrophic event resulting in a species or larger taxonomic group dying out abruptly at a particular point in geological history. Such extinctions are thought to be cyclical, occurring every 28.4 million years, and have been attributed to cosmic activity such as showers of large asteroids or comets, though neither the periodicity nor its causes are at present universally accepted.

extinction

the disappearance of a conditioned response as a result of nonreinforcement.
References in periodicals archive ?
These efforts by the winery will significantly help our cause to save every hummingbird that is at risk of extinction.
Because of the bears' critically low numbers, these latest poaching episodes may have pushed the bears in these ecosystems into extinction.
Keller has joined other scientists in focusing her research on the 30-year-old idea first championed by Virginia Tech geologist Dewey McLean that Deccan volcanism was the root of the Cretaceous mass extinction.
Dark Vanishings: Discourse on the Extinction of Primitive Races, 1800-1930, by Patrick Brantlinger.
The researchers have "found the smoking gun for this extinction event," says geoscientist Richard Ernst of Carleton University in Ottawa.
Scientists associate mass extinction events like the Cretaceous-Paleogene (abbreviated K-Pg) event with a reduction in organism size in the aftermath, a phenomenon termed 'the Lilliput effect.
Corridors to extinction and the Australian megafauna.
Second, the premise of Spielberg's and Crichton's film seems to be that the human race is endangered because a group of prehistoric creatures have been imprudently brought back from extinction and reintroduced into our modern ecosystem.
Myers first gained the public eye with his 1979 book The Sinking Ark, which posits that species extinction is running rampant.
Furthermore, until larger issues such as international fish export agreements are addressed, local efforts to prevent wildlife extinction will fall short.
Peter D Ward is one of maybe a dozen leading scholars of the Permian extinction.
Yet within the scientific community, the debate over extinction rates is about details, like just how much extrapolation is appropriate, rather than the big picture.