Sexual selection and the handicap principle

Population genetic models have shown that female choice is a potential cause of the evolution of male display. In these models the display is assumed to be the immediate object of female choice. Here I present an explicit genetic model that shows that male display can evolve as a consequence of female choice even when the display is not the immediate object of choice. When females initially base their preferences on the existence of variance in a cue that is correlated with male viability, a rare display can evolve to fixation if it amplifies the previously recognized differences in males, (i. e. if it increases the resolution power of females with respect to the original cue). By definition, amplifying displays (or amplifiers) increase mating success of the more viable males and decrease mating success of the less viable males. Therefore, the higher the frequency of the preferred, more viable males, the more likely it is that amplifiers will evolve to fixation. The evolution of an amplifier is further facilitated by a genetic association that is built up between the amplifier allele and the more viable allele. If the expression of the amplifier is limited to the more viable males, the amplifier will evolve to fixation provided only that the change in total fitness to the more viable males (higher mating success, lower viability), is positive.

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SEXUAL SELECTION, HONEST ADVERTISEMENT AND THE HANDICAP PRINCIPLE: REVIEWING THE EVIDENCE

Biological Reviews ◽

10.1111/j.1469-185x.1995.tb01439.x ◽

1995 ◽

Vol 70 (1) ◽

pp. 1-65 ◽

Cited By ~ 397

Author(s):

RUFUS A. JOHNSTONE

Keyword(s):

Sexual Selection ◽

Handicap Principle

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Sexual Selection, Signal Selection and the Handicap Principle

Reproductive Biology and Phylogeny of Birds, Part B: Sexual Selection, Behavior, Conservation, Embryology and Genetics ◽

10.1201/9781482280517-7 ◽

2007 ◽

pp. 153-170

Keyword(s):

Sexual Selection ◽

Handicap Principle ◽

Signal Selection ◽

Selection Signal

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Signalling among relatives. I. Is costly signalling too costly?

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1997.0041 ◽

1997 ◽

Vol 352 (1353) ◽

pp. 609-617 ◽

Cited By ~ 73

Author(s):

Carl T. Bergstrom ◽

Michael Lachmann

Keyword(s):

Sexual Selection ◽

Information Transfer ◽

Sir Philip Sidney ◽

Handicap Principle ◽

Signalling System ◽

Signal Value ◽

Related Individuals ◽

Signalling Systems

Zahavi's handicap principle,originally proposed as an explanation for sexual selection ofelaborate male traits, suggests that a sufficient cost to dishonest signals can outweigh the rewards of deception and allow individuals to communicate honestly. Maynard Smith (1991) and Johnstone and Grafen (1992) introduce the Sir Philip Sidney game in order to extend the handicap principle to interactions among related individuals, and to demonstrate that stable costly signalling systems can exist among relatives. In this paper we demonstrate that despite the benefits associated with honest information transfer, the costs incurred in a stable costly signalling system may leave all participants worse off than they would be in a system with no signalling at all. In both the discrete and continuous forms of the Sir Philip Sidney game, there exist conditions under which costly signalling among relatives, while stable, is so costly that it is disadvantageous compared with no signalling at all. We determine the factors which dictate signal cost and signal benefit in a generalized version of this game, and explain how signal cost can exceed signal value. Such results raise concerns about theevolutionary pathways which could have led to the existence of signalling equilibria in nature. The paper stresses the importance of comparing signalling equilibria with other possible strategies, beforedrawing conclusions regarding the optimality of signalling.

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