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The physiological density or real population density is the number of people per unit area of arable land . A higher physiological density suggests that the available agricultural land is being used by more and may reach its output limit sooner than a country that has a lower physiological density. Egypt is a notable example, with physiological ...
Population density is the number of people per unit of area, usually transcribed as "per square kilometer" or square mile, and which may include or exclude, for example, areas of water or glaciers. Commonly this is calculated for a county, city, country, another territory or the entire world . The world's population is around 8,000,000,000 [3 ...
John B. Calhoun. John Calhoun (age 69) in the fall of 1986 at the baby shower of his first grandchild. John Bumpass Calhoun (May 11, 1917 – September 7, 1995) was an American ethologist and behavioral researcher noted for his studies of population density and its effects on behavior. He claimed that the bleak effects of overpopulation on ...
Population dynamics has traditionally been the dominant branch of mathematical biology, which has a history of more than 220 years, [1] although over the last century the scope of mathematical biology has greatly expanded. [citation needed] The beginning of population dynamics is widely regarded as the work of Malthus, formulated as the ...
Behavioral sink. " Behavioral sink " is a term invented by ethologist John B. Calhoun to describe a collapse in behavior that can result from overpopulation. The term and concept derive from a series of over-population experiments Calhoun conducted on Norway rats between 1958 and 1962. [1] In the experiments, Calhoun and his researchers created ...
A demographic structure of a population is how populations are often quantified. The total number of individuals in a population is defined as a population size, and how dense these individuals are is defined as population density. There is also a population's geographic range, which has limits that a species can tolerate (such as temperature).
The term population biology has been used with different meanings. In 1971, Edward O. Wilson et al. used the term in the sense of applying mathematical models to population genetics, community ecology, and population dynamics. [1] Alan Hastings used the term in 1997 as the title of his book on the mathematics used in population dynamics. [2]
r. /. K. selection theory. A North Atlantic right whale with solitary calf. Whale reproduction follows a K -selection strategy, with few offspring, long gestation, long parental care, and a long period until sexual maturity. In ecology, r/K selection theory relates to the selection of combinations of traits in an organism that trade off between ...