| The Extended Phenotype | |
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 |
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| Author(s) | Richard Dawkins |
| Subject(s) | Evolutionary biology |
| Publisher | Oxford University Press |
| Publication date | 1982 |
| Pages | 307 |
| ISBN | 0-19-286088-7 |
| OCLC Number | 19921696 |
| Dewey Decimal | 575 20 |
| LC Classification | QH375 .D38 1983 |
| Preceded by | The Selfish Gene |
| Followed by | The Blind Watchmaker |
The Extended Phenotype is a biological concept introduced by Richard Dawkins in a 1982 book with the same title. The main idea is that phenotype should not be limited to biological processes such as protein biosynthesis or tissue growth, but extended to include all effects that a gene has on its environment, inside or outside of the body of the individual organism.
Dawkins considers the Extended Phenotype to be his principal contribution to evolutionary theory.[1]
Contents |
Genes synthesize only proteins [edit]
In the main portion of the book, Dawkins argues that the only thing that genes control directly is the synthesis of proteins. He points to the arbitrariness of restricting the idea of the phenotype to apply only to the phenotypic expression of an organism's genes in its own body.
Genes affect the organism’s environment [edit]
Dawkins develops this idea by pointing to the effect that a gene may have on an organism's environment through that organism's behaviour, citing as examples caddis houses and beaver dams. He then goes further to point to first animal morphology and ultimately animal behaviour, which can seem advantageous not to the animal itself, but rather to a parasite which afflicts it. Such behaviour is seen, for example, in a study that found that female mosquitoes carrying malaria parasites are significantly more attracted to human breath and odours than uninfected mosquitoes. [2]
Dawkins summarizes these ideas in what he terms the Central Theorem of the Extended Phenotype:
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An animal's behaviour tends to maximize the survival of the genes "for" that behaviour, whether or not those genes happen to be in the body of the particular animal performing it.[1] |
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Gene-centred view of life [edit]
In conducting this argument, Dawkins aims to strengthen the case for a gene-centric view of life, to the point where it is recognized that the organism itself needs to be explained. This is the challenge which he takes up in the final chapter entitled "Rediscovering the Organism."
See also [edit]
References [edit]
- ^ a b Dawkins, Richard (1989). The Extended Phenotype. Oxford: Oxford University Press. p. xiii. ISBN 0-19-288051-9.
- ^ http://www.newscientist.com/article/dn23543-malaria-bug-may-give-mosquitoes-a-super-sense-of-smell.html
External links [edit]
- From The World of Richard Dawkins
- Video of cricket exhibiting behavioral extended phenotype of parasite
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