Red Queen hypothesis

The Red Queen hypothesis, also referred to as Red Queen's, Red Queen's race or the Red Queen effect, is an evolutionary hypothesis which proposes that organisms must constantly adapt, evolve, and proliferate not merely to gain reproductive advantage, but also simply to survive while pitted against ever-evolving opposing organisms in an ever-changing environment. The hypothesis intends to explain two different phenomena: the constant extinction rates as observed in the paleontological record caused by co-evolution between competing species, and the advantage of sexual reproduction (as opposed to asexual reproduction) at the level of individuals.

Leigh Van Valen proposed the hypothesis to explain the "Law of Extinction", showing that, in many populations, the probability of extinction does not depend on the lifetime of the population, instead being constant over millions of years for a given population. This could be explained by the coevolution of species. At other times, established species have evolved cooperatively by assuming adaptive coevolutionary dependencies. These complementary relationships develop through graduated symbiosis, directing punctuated advantages specialized enough to ensure a greater survivability and fitness rate for both species, coupled. Indeed, however, an adaptation in a population of one species (e.g. predators, parasites) may change the natural selection pressure on a population of another species (e.g. prey, hosts), giving rise to common antagonistic coevolutions. If this positive feedback occurs reciprocally, a potential dynamic coevolution may result.

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