Fisher's runaway ( Fisherian runaway ) - a hypothetical sexual selection mechanism proposed by Ronald Fisher at the beginning of the 20th century, designed to explain the evolution of non-adaptive, biologically neutral traits - in particular, hypertrophic mating ornaments found in males of many species of living creatures that are characterized by sexual reproduction . Fisher described the mechanism due to which the preference on the part of the females and, as a consequence, the reproductive advantage, were obtained by the most “decorated” males.
The evolution of male jewelry, an example of which is the colorful tail of male peacocks , which differs significantly from the more modest tail of females, is a paradox for evolutionary biologists , from Charles Darwin to the modern synthetic theory of evolution . The selection of individuals with expensive and often disadvantageous jewelry for personal survival seems incompatible with natural selection . The theory of Fischer runaway is an attempt to resolve this paradox using a putative genetic mechanism that explains both the preferences of females and the appearance of males based on the principle of sexual selection .
The hypothesis of the author of the theory is that females choose attractive males with the most developed decorative characters only because of the males possessing these characters - unlike the handicap concept , where females are supposed to take into account how these jewelry makes life difficult for the male and therefore testify about his best fitness in general. According to Fisher, males with more developed ornaments, accidentally arising due to mutations, can lead to the fact that males with a higher degree of development of this trait begin to leave more offspring than those that have this trait to a lesser extent. As a result, the next generation inherits both more developed ornaments in males and preferences of females for such males. Thus, a positive feedback mechanism arises, fixing both the sign and its preference [1] .
Fisher's hypothesis has become a topic of lively discussion, which has not been completed so far. Alternative explanations of this effect were put forward and substantiated [2] .
Notes
- ↑ Markov, 2011 , p. 396.
- ↑ Zhukov, 2017 , p. 34-42.
Literature
- Markov A.V. Human evolution. - Astrel, 2011 .-- T. I. - 464 p. - ISBN 978-5-271-36293-4 .
- Zhukov B. Beauty contests as an engine of evolution // Science and Life. - 2017. - No. 7.