News tagged with extinction
Researchers at Boston University School of Medicine (BUSM) have, for the first time, identified a specific group of cells in the brainstem whose activation during rapid eye movement (REM) sleep is critical for the regulation ...
Neuroscience Mar 05, 2013 | 5 / 5 (3) | 0 |
(Medical Xpress)—The drug scopolamine has been used to treat a variety of conditions, including nausea and motion sickness. A new study by UCLA life scientists suggests that it may also be useful in treating anxiety disorders.
Psychology & Psychiatry Feb 21, 2013 | not rated yet | 0 |
Cuba's Public Health Ministry on Tuesday acknowledged 51 new cases of cholera in the capital amid growing concerns about the illness' spread and disappointment in the diplomatic community over the government's lack of transparency.
Diseases, Conditions, Syndromes Jan 15, 2013 | not rated yet | 0
(Medical Xpress)—Researchers at Stanford University have developed a procedure that reduces a fear response in mice. It involves, team lead Asya Rolls said as she presented the groups' findings at this year's ...
Neuroscience Oct 19, 2012 | 5 / 5 (1) | 1 |
Researchers from the University of Wisconsin-Milwaukee (UWM) have identified mechanisms in the brain responsible for regulating cocaine-seeking behavior, providing an avenue for drug development that could greatly reduce ...
Neuroscience Oct 17, 2012 | not rated yet | 0 |
A new study by Weill Cornell Medical College researchers shows that adolescents' reactions to threat remain high even when the danger is no longer present. According to researchers, once a teenager's brain is triggered by ...
Psychology & Psychiatry Sep 27, 2012 | 4.2 / 5 (5) | 8 |
Exposure therapy for irrational fear of spiders seems to be more effective if it is followed by sleep, according to a recent study in the Journal of Psychiatric Research. The results have implications for treatme ...
Psychology & Psychiatry Jul 24, 2012 | 5 / 5 (2) | 0
(Medical Xpress) -- Traditionally, treatment for drug addicts has centered around so-called extinction procedures designed to disassociate memories tied with taking drugs to help reduce the cravings that so often result in ...
Addiction Apr 13, 2012 | 4.7 / 5 (6) | 0 |
(Medical Xpress) -- The antidepressant fluoxetine, which is marketed under the name "Prozac," has been approved for use in the US for over two decades, and while some people find it effective, the results ...
Neuroscience Dec 23, 2011 | 3.6 / 5 (5) | 0 |
(Medical Xpress) -- In a new study, University of Michigan researchers identified brain circuits in rats that are responsible for the return of fear after it has been suppressed behaviorally.
Neuroscience Nov 29, 2011 | not rated yet | 0 |
(Medical Xpress) -- Neuroscientists at UQ's Queensland Brain Institute have discovered a previously unrecognized layer of gene regulation associated with fear extinction.
Neuroscience Aug 15, 2011 | 5 / 5 (2) | 0 |
In biology and ecology, extinction is the end of a species or group of taxa. The moment of extinction is generally considered to be the death of the last individual of that species (although the capacity to breed and recover may have been lost before this point). Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "re-appears" (typically in the fossil record) after a period of apparent absence.
Through evolution, new species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive virtually unchanged for hundreds of millions of years. Extinction, though, is usually a natural phenomenon; it is estimated that 99.9% of all species that have ever lived are now extinct.
Prior to the dispersion of humans across the earth, extinction generally occurred at a continuous low rate, mass extinctions being relatively rare events. Starting approximately 100,000 years ago, and coinciding with an increase in the numbers and range of humans, species extinctions have increased to a rate unprecedented since the Cretaceous–Tertiary extinction event. This is known as the Holocene extinction event and is at least the sixth such extinction event. Some experts have estimated that up to half of presently existing species may become extinct by 2100.
For more information about Extinction, read the full article at
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