News tagged with population size

Related topics: population



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 and is available under the GNU Free Documentation License.


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 ...

Health created Apr 30, 2013 | popularity not rated yet | comments 0

Screening could avert 12,000 lung cancer deaths each year in the US

Screening for lung cancer with low-dose computed tomography (LDCT) in all screening-eligible current and former smokers has the potential to avert approximately 12,000 lung cancer deaths each year in the United States. That ...

Cancer created Feb 25, 2013 | popularity 5 / 5 (1) | comments 0

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.

Cancer created Feb 01, 2013 | popularity 5 / 5 (1) | comments 0

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 ...

Genetics created Dec 14, 2012 | popularity 5 / 5 (2) | comments 0 | with audio podcast

Harmful protein-coding mutations in people arose largely in the past 5,000 to 10,000 years (Update)

(Medical Xpress)—A study dating the age of more than 1 million single-letter variations in the human DNA code reveals that most of these mutations are of recent origin, evolutionarily speaking. These kinds ...

Genetics created Nov 28, 2012 | popularity 4.5 / 5 (4) | comments 1 | with audio podcast

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 ...

Dentistry created Aug 28, 2012 | popularity not rated yet | comments 0

Unique scientific collaboration reveals hard facts on European drug use

Surveys of drug use form an important basis for the development of effective drug policies, and also for measuring the effectiveness of existing policies. For the first time in history, scientists have now made direct comparisons ...

Addiction created Jul 26, 2012 | popularity not rated yet | comments 0

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 ...

Cancer created May 31, 2012 | popularity 5 / 5 (2) | comments 0 | with audio podcast

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.

Other created Aug 11, 2011 | popularity not rated yet | comments 0