Evolutionary suicide

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Evolutionary suicide the an idea that the adaptation of an individual animal works in such a way that an entire species dies out. This is different from group selection where the biological fitness of an animal is linked to the entire population.

The idea is that evolution makes plants and animals pass on their genes to the next generation more efficiently, but it does not guarantee the survival of the population or the species.[1] For this reason, the evolutionary benefit of an individual and its descendants might lead to the extinction of the respective population, or the whole species.

An example of this would be that an animal of a population starts to eat the seeds, or the buds of a food plant. This would destroy the supply of plants that would usually be available. All animals would then starve.

As of 2010, there is no proof that evolutionary suicide exists. Different scientific studies found a correlation between acquired traits and a higher risk of a population disappearing.[2]

A candidate for a future evolutionary suicide migh be cod. Cod is caught as fish by humans. There is evolutionary pressure on the bigger fish, which are caught. This has led to the fish not growing as much as they used to. They also mature earlier.[3][4] These adaptations are a reaction that should save the species from becoming extinct, in the short run. They do however also mean that the amount of offspring per fish is reduced. This bears the risk of the population becoming extinct.[5]

References[change | edit source]

  1. D. J. Rankin et al.: Species-level selection reduces selfishness through competitive exclusion. In: J Evol Biol. 20, 2007, pp 1459–1468. PMID 17584239
  2. E. H. Morrow & T. E. Pitcher: Sexual selection and the risk of extinction in birds. In: Proc Biol Sci. 270, 2003, pp. 1793–1799. PMID 12964981
  3. E. M. Olsen et al.: Maturation trends indicative of rapid evolution preceded the collapse of northern cod. In: Nature. 428, 2004, pp. 932–935. PMID 15118724
  4. D. O. Conover & S. B. Munch: Sustaining fisheries yields over evolutionary time scales. In: Science. 297, 2002, pp. 94–96. PMID 12098697
  5. F. Courchamp et al.: Allee effects in ecology and conservation. Oxford University Press, 2008, ISBN 0-198-57030-9 S. 156