PPT-Chapter 7: Sexual Selection

Intersexual and Intrasexual Selection Evolutionary Models of Mate Choice Learning and Mate Choice Cultural Transmission and Mate Choice MaleMale Competition and Mate Choice I n 1860 Charles Darwin wrote in a letter to his friend Asa Gray that the sight of a feather in a peacocks tail whenever I gaze at it makes me sick Darwin was worried that the peacocks tail couldnt possibly help in its survival and thus could be construed as evidence against his grand theory of evolution by natural selection. In fact we already did this when we were discussing the ABO blood group polymorphism Just to get some notation out of the way though lets de64257ne ij as the frequency of genotype and as the frequency of allele Then ij if if Unfortunately the simpl brPage 4br Mate Guarding Titi monkey male showing mate guarding by preventing female partner from visiting male neighbor brPage 5br Humans have malemale competition Topkapi Harem then and now brPage 6br Mean number of offspring for males and females Misleading signals of . crypsis. Warning signals of aposematism. S. ignals as isolating mechanisms. Sexual selection. Parental social selection. Membracid bizzare may be sensory crypsis. Neuron stereotypy and the omega neuron. Evolutionary Mechanisms. Genetic Drift . Migration. Mutations. Natural Selection. Non-adaptive. Adaptive. Natural. . . Selection. (1) Sexual Selection. (2) Constraints on Natural Selection. Pleiotropy. - Recognized as a deviation from predictions offered by a strict selection model. . In this case, there are different selective pressures on each SEX.. Sexual Selection . - Recognized as a deviation from predictions offered by a strict selection model.. Population Genetics . DEFINITIONS. POPULATION. : a localized group of individuals belonging to the same species. . SPECIES. : a group of populations whose individuals have the potential to . interbreed and produce fertile offspring. involves…. A. the acceptance of all hypotheses. .. B. rejection of hypotheses that are inconsistent with experimental results. .. C. the acceptance of only data consistent with the hypothesis. .. 2014. Why learn about evolution in . Env. . Ed?. Extinction is important. -95-99% of species that have ever existed are now extinct. -this allows “an opening” for other creatures to develop . -the current mass extinction event is not natural which causes a concern for some. In Birds of Prey. By: Angel Gosnell. Reverse of the norm. In normal size dimorphism, males are typically larger than females due to intrasexual selective pressures. . In RSD, females are larger than males. . Evolutionary Mechanisms. Genetic Drift . Migration. Mutations. Natural Selection. Non-adaptive. Adaptive. Natural. . . Selection. (1) Sexual Selection. (2) Constraints on Natural Selection. Pleiotropy. SEXUAL SELECTION. John Hunter . (1728-1793). John Hunter. -distinguished primary sexual characteristics (those present at birth) . from . secondary sexual characteristics (those that appear with sexual maturity). Solomon Chak. Virginia Scientists & Educators Alliance – VA SEA. 2016. I. Background. Top : . ChrisO. at . English . Wikipedia. Bottom: . Hagerty. . Ryan, U.S.FWS . , public domain. Top: Darwin . Intersexual and . Intrasexual. Selection. Evolutionary Models of Mate Choice. Learning and Mate Choice. Cultural Transmission and Mate Choice. Male-Male Competition and Mate Choice. I. n 1860, . Charles Darwin wrote in a letter to his friend Asa Gray that “…the sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick!” Darwin was worried that the peacock’s tail couldn’t possibly help in its survival, and thus could be construed as evidence against his grand theory of evolution by natural selection.. In this case, there are different selective pressures on each SEX.. Sexual Selection . - Recognized as a deviation from predictions offered by a strict selection model.. 1. The Basics. Sexual Selection .