PSYCH 3F03 Lecture Notes - Lecture 8: Homicide, Anisogamy, Parental Investment
13 Apr 2018
School
Department
Course
Professor
Document Summary
Component of natural selection differential access to mates or gametes, (cid:271)e(cid:272)ause of : vanquishing same-sex rivals (intrasexual selection, being chosen by the opposite sex (intersexual selection) Favours traits that natural selection, under other circumstances, would tend to oppose. Anisogamy differential size and number of gametes: distinguishes males from females in an evolutionary sense. Males gai(cid:374) fit(cid:374)ess fro(cid:373) additio(cid:374)al (cid:373)ates i(cid:374) a (cid:449)a(cid:455) fe(cid:373)ales do(cid:374)"t. Males reproductive success (rs) is always more variable than female rs: male rs increases with # of mates, female rs does not. Ex. honey locust beetles (sex-role reversed) manipulated to be m-biased or f-biased: f biased osr more sex role reversed; m biased osr less sex role reversed. Ratio of male fitness variance to female fitness variance: monogamous = 1, effectively polygynous > 1, effectively polyandrous < 1. For every many who acquires an additional wife, another man has none osr influenced by effective polygyny.
