News tagged with population size
New analysis shows 'hobbits' couldn't hustle
A detailed analysis of the feet of Homo floresiensis—the miniature hominins who lived on a remote island in eastern Indonesia until 18,000 years ago -- may help settle a question hotly debated among paleontologists: how si ...
Other Sciences / Archaeology & Fossils
May 06, 2009 |
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Buried Coins Key to Roman Population Mystery?
(PhysOrg.com) -- The first century BC in Italy was culturally a brilliant age, unequaled by any other period in Roman history. It was a time of Cicero, Caesar, Vergil, Horace and many other major literary ...
Oct 05, 2009 |
3.5 / 5 (14) |
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High population density triggers cultural explosions
Increasing population density, rather than boosts in human brain power, appears to have catalysed the emergence of modern human behaviour, according to a new study by UCL (University College London) scientists published in ...
Other Sciences / Social Sciences
Jun 04, 2009 |
4.8 / 5 (8) |
3
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 |
3.5 / 5 (11) |
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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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Physicists Show that Correlated Environmental Variations Can Quicken Extinctions
(PhysOrg.com) -- In general, population extinction is a natural process. For one reason or another, an estimated 99.9% of all species that have lived on Earth are now extinct. However, the reasons for a species ...
Jan 13, 2009 |
4 / 5 (7) |
5
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 |
4.8 / 5 (5) |
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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 |
3.8 / 5 (4) |
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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 |
5 / 5 (3) |
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Big-mouthed babies drove the evolution of giant island snakes
Some populations of tiger snakes stranded for thousands of years on tiny islands surrounding Australia have evolved to be giants, growing to nearly twice the size of their mainland cousins. Now, new research ...
May 15, 2012 |
5 / 5 (3) |
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Study finds human population expanded during late Stone Age
Genetic evidence is revealing that human populations began to expand in size in Africa during the Late Stone Age approximately 40,000 years ago. A research team led by Michael F. Hammer (Arizona Research Laboratory's Division ...
Jul 29, 2009 |
4.3 / 5 (3) |
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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 |
5 / 5 (2) |
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Seals quickly respond to gain and loss of habitat under climate change
Southern Elephant seals responded rapidly to climate and habitat change and established a new breeding site thousands of kilometres from existing breeding grounds, according to new research.
Jul 10, 2009 |
4 / 5 (2) |
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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 |
3.5 / 5 (2) |
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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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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.
