lecture 17 - Inter-sexual selection Choosey females Female...

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Inter-sexual selection Choosey females Female choice occurs, and females make good choices Genetic benefits “Good genes” vs. “sexy son”
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Stalk eyed flies: Diopsidae
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Fisher (1930) – Runaway sexual selection Initially, males have a trait (e.g., long eye stalks) that provides a benefit. Female preference leads to a double advantage: fitness and attractiveness Positive feedback loop can lead to a maladaptive trait that ensures mating success but not necessarily fitness. “Sexy sons,” but not necessarily good genes
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Handicap principle (Zahavi 1975) Heritable trait with an energetic cost, reduces viability. ‘High-quality’ males can survive despite the handicap Often expression of the trait is linked to physical condition…degree informs quality “Good genes” hypothesis – this is an honest signal of fitness
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Fit individuals can have greater handicaps They produce larger ornaments Handicap size advertises fitness Receivers' preference for large handicaps is justified
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This note was uploaded on 02/27/2010 for the course ENTOMOLOGY ent 104 taught by Professor Edwinlewis during the Spring '10 term at UC Davis.

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lecture 17 - Inter-sexual selection Choosey females Female...

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