Red Queen's Hypothesis

Red Queen's 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 Red Queen 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 at the level of individuals.

The original idea of the Red Queen hypothesis (macroevolutionary) was given by Leigh Van Valen in order to explain the “Law of Extinction”. Leigh Van Valen showed that in many populations the probability of extinction does not depend on the lifetime of this population. In addition, the probability of extinction is constant over millions of years for a given population. This could be explained by the coevolution. Indeed, an adaptation in a population of one species (e.g. predators, parasites ...) may change the selection pressure on a population of another species (e.g., prey, hosts), giving rise to an antagonistic coevolution. If this occurs reciprocally, a potential dynamic coevolution may result. The phenomenon's name is derived from a statement that the Red Queen made to Alice in Lewis Carroll's Through the Looking-Glass in her explanation of the nature of Wonderland:

Now, here, you see, it takes all the running you can do, to keep in the same place.

In another idea (microevolutionary), the Red Queen hypothesis is used by Bell to explain the evolution of sex, by John Jaenike to explain the maintenance of sex and W. D. Hamilton explain the role of sex in response to parasite. In all cases, sexual reproduction allows to create variability and a faster response to selection by making offspring genetically unique. Sexual organisms are able to improve their genotype in function of changing conditions. Consequently a co-evolutionary interactions, between host and parasite for example, may select for a sexual reproduction in hosts in order to reduce the risk of infection. Oscillations in genotype frequencies are observed between parasites and host in an antagonistic coevolution way. Once again, the two stay at the same place.