Search results
Results from the WOW.Com Content Network
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 ...
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 ...
Recruitment in behavioral ecology. In behavioral ecology and studies of animal communication, recruitment is the process by which individuals in a social group direct other individuals to do certain tasks. [2] This is often achieved through the use of recruitment pheromones that direct anywhere from one to several hundred individuals to ...
This is a list of countries and dependencies ranked by population density, sorted by inhabitants per square kilometre or square mile. The list includes sovereign states and self-governing dependent territories based upon the ISO standard ISO 3166-1. The list also includes unrecognized but de facto independent countries.
Delayed density dependence has been used by ecologists to explain population cycles. [2] Ecologists have been unable to successfully explain regular population cycles for many decades; delayed density dependence may hold the answer. [2] Here populations are allowed to increase above their normal capacity because there is a time lag until ...
Genetic isolate. A genetic isolate is a population of organisms that has little to no genetic mixing with other organisms of the same species due to geographic isolation or other factors that prevent reproduction. Genetic isolates form new species through an evolutionary process known as speciation.
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 ...
Life history theory. Life history theory ( LHT) is an analytical framework [1] designed to study the diversity of life history strategies used by different organisms throughout the world, as well as the causes and results of the variation in their life cycles. [2] It is a theory of biological evolution that seeks to explain aspects of organisms ...