Fisher's Fundamental Theorem of Natural Selection

from Wikipedia, the free encyclopedia

The fundamental theorem of natural selection formulates mathematical laws of population genetics for increasing the fitness of organisms .

history

Ronald Fisher (1913)

The theorem was first formulated by Ronald Fisher in his book The Genetical Theory of Natural Selection in 1930:

"The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time."

"The rate of increase in fitness of any organism at any time is equal to the genetic variance of its fitness at that time."

- Ronald Aylmer Fisher

Or, in more modern terminology :

"The rate of increase in the mean fitness of any organism at any time ascribable to natural selection acting through changes in gene frequencies is exactly equal to its genetic variance in fitness at that time."

"The increase in the mean fitness of every organism, which follows from natural selection at any point in time and is mediated by a change in the gene frequency , is exactly the same as the genetic variance in fitness at this point in time."

- Anthony William Fairbank Edwards

Fisher stated that it was "not a little revealing that, like a law, it should hold the highest position among the biological sciences". Even so, for forty years it has been misunderstood and read as if it were to say that the average fitness of a population would always go up, even though models showed it wasn't. The misunderstandings can largely be seen as a result of Fischer's feud with the American geneticist Sewall Wright , which mainly centered on the theme of fitness landscapes .

The American George R. Price showed in 1972 the correctness of Fisher's theorem and that the proof is also correct, except for one or two typing errors. (see Fischers equation ). Price showed the results were correct but did not see this as being of great significance. The sophistication Price pointed out, which made it difficult to understand, is that the theorem gives a formula for some of the changes in gene frequency, but not all of them. This is a part that is due to natural selection.

More recent work (examined in Grafen 2003) builds on Price's understanding in two ways. One aims to improve the theorem by completing it, for example by finding a formula for the set of changes in gene frequency. The other argues that the partial change does indeed have great conceptual significance and aims to extend similar results of the partial change into increasingly general population genetic models.

Because of the irritating factors, tests of the fundamental theorem are rare. For an example of this effect in a natural population, see Bolnick, 2007.

Individual evidence

  1. ^ A b Ronald Aylmer Fisher : The Genetical Theory of Natural Selection , Clarendon Press, Oxford 1930
  2. ^ Anthony William Fairbank Edwards: The fundamental theorem of natural selection. In: Biological Reviews 69 : pp. 443-474, 1994
  3. ↑ George R. Price : Fisher's "fundamental theorem" made clear. In: Annals of Human Genetics 36 : pp. 129-140, 1972
  4. ↑ DI Bolnick, P. Nosil: Natural Selection in Populations Subject to a Migration Load. Evolution, Advance access , doi: 10.1111 / j.1558-5646.2007.00179.x

literature

  • DR Brooks, EO Wiley: Evolution as Entropy, Towards a unified theory of Biology. The University of Chicago Press, 1986
  • WJ Ewens: An interpretation and proof of the Fundamental Theorem of Natural Selection. Theor. Pop. Biol. 36 : pp. 167-180, 1989
  • SA Frank: The Price Equation, Fisher's fundamental theorem, kin selection, and causal analysis. Evolution 51 : pp. 1712-1729. Abstract , 1997
  • SA Frank: Foundation of Social Evolution , Princeton University Press ( website of the book ), Princeton 1998, ISBN 0-691-05934-9
  • SA Frank, M. Slatkin: Fisher's fundamental theorem of natural selection. Trends in Ecology and Evolution 7 : pp. 92-95. Abstract , 1992
  • A. Grafen: Developments of the price equation and natural selection under uncertainty. Proceedings of the Royal Society of London B, 267 : pp. 1223-1227, 2000
  • A. Grafen: A first formal link between the Price equation and an optimization program. Journal of Theoretical Biology 217 : pp. 75-91, 2002
  • A. Grafen: Fisher the evolutionary biologist. Journal of the Royal Statistical Society: Series D (The Statistician), 52 : pp. 319-329, 2003
  • G. Kjellström: Evolution as a statistical optimization algorithm. Evolutionary Theory 11 : pp. 105-117, January, 1996.
  • Maynard Smith: J. Evolutionary Genetics. Oxford University Press, 1998.
  • E. Mayr: What evolution is. Basic Books, New York 2001.

Web links