News tagged with population size
Bird populations near Fukushima are more diminished than expected
(PhysOrg.com) -- Low-level radiation in Fukushima Prefecture appears to have had immediate effects on bird populations, and to a greater degree than was expected from a related analysis of Chernobyl, an international ...
Feb 09, 2012 |
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New fluorescent imaging sorts microbiome in human mouth
New fluorescent labeling technology that distinguishes in a single image the population size and spatial distribution of 15 different taxa has uncovered new taxon pairings that indicate unsuspected cooperation -- and standoffishness ...
Dec 07, 2011 |
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Powerful mathematical model greatly improves predictions for species facing climate change
UCLA life scientists and colleagues have produced the most comprehensive mathematical model ever devised to track the health of populations exposed to environmental change.
Dec 03, 2011 |
4.3 / 5 (7) |
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Study of wolves will help scientists predict climate effects on endangered animals
Scientists studying populations of gray wolves in the USA's Yellowstone National Park have developed a way to predict how changes in the environment will impact on the animals' number, body size and genetics, amongst other ...
Dec 01, 2011 |
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How does a plant survive with few mates or pollinators? A European herb has figured out its own way
In plants that rely on animals for pollination, the number of seeds they produce, or their relative fitness, is influenced by pollinator visits and the successful deposition of pollen. The number of visits ...
Nov 10, 2011 |
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Between geometry and biology: How and why does the number of species depend on area
There are few universal rules in ecology, but arguably one is the relationship between the area of a study plot and the number of species counted within that plot, the so called species-area relationship. Larger study plots ...
Nov 10, 2011 |
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After-hours care affects emergency department use in Leduc
(Edmonton, Canada) Access to health care and the usage of emergency departments are popular topics in the news.
Aug 11, 2011 |
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Atlantic herring population trends linked to egg predation by haddock
(PhysOrg.com) -- NOAA scientists have developed a population model for Atlantic herring that links herring population trends to the size of the haddock population. The model also provides evidence that egg predation by haddock ...
Aug 09, 2011 |
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There's no magic number for saving endangered species
A new study offers hope for species such as the Siberian Tiger that might be considered 'too rare to save', so long as conservation efforts can target key threats.
May 16, 2011 |
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Bats keep separate households
(PhysOrg.com) -- The use of different resources by males and females exacerbates the estimation of population sizes. However, the monitoring of population sizes, particularly for rare and threatened species, ...
Mar 24, 2011 |
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Why New York City is average: Researchers want to improve how we determine urban exceptionality?
Think New York is an exceptional city? It's not. The Big Apple is just about average for a city of its size. However, San Francisco is exceptional. Its inhabitants are wealthier, more productive, more innovative, and subject ...
Other Sciences / Social Sciences
Nov 10, 2010 |
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Population trends: Another influence on climate change
Changes in population growth and composition, including aging and urbanization, could significantly affect global emissions of carbon dioxide over the next 40 years, according to a new study out next week.
Oct 11, 2010 |
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Largest ever white-shouldered ibis count
A record-breaking 429 White-shouldered Ibis Pseudibis davisoni have just been recorded in Cambodia, making the known global population much larger than previously thought. With so many birds remaining in the wild the chance ...
Sep 14, 2010 |
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'Ribbit Radio' shows frog population estimates are likely flawed
Scientists track amphibian populations because these animals are sensitive to changes in their environment and can serve as "canaries in the coal mine" to give researchers early warnings about pollution or ...
Aug 02, 2010 |
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Climate change causes larger, more plentiful marmots, study shows
This week, one of the world's foremost scientific journals will publish results of a decades-long research project founded at the University of Kansas showing that mountain rodents called marmots are growing ...
Jul 21, 2010 |
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Population size
In population genetics and population ecology, population size (usually denoted N) is the number of individual organisms in a population.
The effective population size (Ne) is defined as "the number of breeding individuals in an idealized population that would show the same amount of dispersion of allele frequencies under random genetic drift or the same amount of inbreeding as the population under consideration." Ne is usually less than N (the absolute population size) and this has important applications in conservation genetics.
Small population size results in increased genetic drift. Population bottlenecks are when population size reduces for a short period of time.
Overpopulation may indicate any case in which the population of any species of animal may exceed the carrying capacity of its ecological niche.
For more information about Population size, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
