LIFESCI 2D03 Lecture Notes - Lecture 15: Sensory System, Guppy, Parental Investment
12 Jan 2018
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Sexual selection favours characteristics that enhance reproductive success. Primary sexual characteristics the genitalia and organs of reproduction. Sexual selection a form of natural selection that acts on heritable traits that affect reproduction: sexual selection = mate competition + mate choice. Mate competition (intrasexual selection) members of the same sex compete for access to the other sex for reproduction: direct aggressive interactions, or contests over resources/breeding territories. Mate choice (intersexual selection) selection by one sex for members of the other sex for reproduction. Males tend to produce many small, motile gametes (sperm) while females tend to produce much larger, nutrient-rich, nonmotile gametes (eggs) Anisogamy the existence of differently sized gametes (small & large) in the different sexes. Isogamy the production of gametes of the same size by all individuals: appears to be the ancestral form (fungi, unicellular protozoans) Model by parker & colleagues assumptions.
