News tagged with population size

Related topics: population

A key gene for brain development

(Medical Xpress)—Neurobiologists at the Research institute of Molecular Pathology (IMP) in Vienna have discovered one of the key genes required to make a brain. Mutations in this gene, called TUBB5, cause ...

Dec 14, 2012
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Cancer incidence predicted to increase 75 percent by 2030

The global cancer burden is set to surge more than 75% by 2030, according to new research published Online First in the Lancet Oncology. The rise is predicted to be even larger in the developing world, with the poorest countr ...

May 31, 2012
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Ovarian cancer risk reduced by prolonged lactation

Curtin University researchers have found that women who breastfeed their babies have significantly reduced rates of ovarian cancer in a study that extends what was known about the beneficial effects of breastfeeding on mothers.

Feb 01, 2013
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Economics influence fertility rates more than other factors

The world population could top 8 billion in the year 2023 if current growth rates remain constant, according to United Nations figures. However, if global fertility rates slow more quickly than expected, there could be up ...

Apr 30, 2013
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New study notes disparities in periodontal disease

A new article by Dr. Luisa N. Borrell, the chair of Lehman College's Department of Health Sciences, explores the disparities in periodontal disease (gum disease) among U.S. adults along age, sex, racial/ethnic and socioeconomic ...

Aug 28, 2012
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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.

This text uses material from Wikipedia licensed under CC BY-SA