BIOL 115 Lecture Notes - Lecture 4: Pleiotropy, Sensory System, Fisherian Runaway
Document Summary
Sexual selection and natural selection: over time (generations) female preference can skew population toward preferential traits, only mate with males that have preferred trait, producing offspring with said traits. Ex. crabs with large claws, at some point claws will become too large that it is inconvenient and natural selection will disallow such an exaggeration. Bateman"s gradient: hypothesized a relationship between mating success and reproductive success, relationship could differ between males and females. Ex. in species where investment might limit the reproductive output of females but not males, mating more frequently doesn"t improve reproductive success for females but it would for males: steep batsman"s gradient: more mates = more offspring. Models and hypotheses: females that are not able to increase reproductive success with additional mating may be able to improve the quality of offspring (and therefore their reproductive success) by choosing a better mate.
