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Unformatted text preview: ETHOLOGY AND COMPARATIVE PSYCHOLOGY – EXAM 5 • Sexual Selection o Darwin in 1871… Isogamy : gametes from both sexes are the same size (microbial organisms) Heterogamy : one gamete much larger than other o Consequences of Heterogamy : (explain sexual selection) 1. Eggs are expensive, sperm are cheap. 2. Female makes ↑ parental investment than male (per gamete) 3. Females have lower Reproductive Value, males ↑ (more gametes produced) 4. Females are selective, males are demonstrative (as many females as possible) 5. Females exhibit lower levels of sexual activity, males ↑ o Conclusions of Heterogamy: Females ought to engage in intersexual (between sexes) selection Males ought to engage in intrasexual (among same sex) selection Males hold resources that females need and fight other males for these goods. • Male – Male competition Females choose males • Intersexual selection o Intersexual Selection – or – Female Choice Male competition as intrasexual selection • Systematic: all females go to one male who has some special advantageous attribute. (genes propagate over time fixing attribute) Drives Evolution • Unsystematic : Choosy Females determine who to mate with equal reproduction success but this doesn’t drive evo o Insights into human nature… o H 2 of personality disorders (acting out) substance abuse H 2 = .81 with normal at .3 o Bare Branches – Asian males of low status/etc, unlikely to reproduce....
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This note was uploaded on 02/26/2008 for the course PSYC 4385 taught by Professor Chizar during the Fall '07 term at Colorado.
- Fall '07