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finalstudyguide - 1. a) Across species, sexual selection...

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Explain why this occurs. As males are the sex with a greater variance in reproductive success, successful heritable male traits are passed more quickly through the population because those who don’t have reproductively successful traits do not pass their genes in the next generation. Therefore, sexual selection acts more strongly on males than on females because favorable sexual traits are passed with greater frequency than nonfavorable sexual traits. b) Describe three human male morphological (not behavioral) attributes thought to have resulted from sexual selection and explain how sexual selection may have acted to produce each. 1. Large power muscles – intrasexual competition over resources 2. Facial hair – intersexual, an orniment for females, help distinguish age and good genes 3. Large penis size – displace other male seminal fluid in vagina c) Compared to other mammalian females, women are unusual in that they seem to exhibit a number of sexually selected morphological traits. Describe two functionally distinct and prominent morphological traits that distinguish human females and explain how these may have been produced by sexual selection. 1. Female breast size – a true sign of age and ability to reproduce, with the perkiness indicating time left to reproduce and the size indicating whether or not she has the fat reserve necessary for late stage and lactacion. Having breasts are not beneficial to females, as the location is not efficient place to store fat and it also displaces her center of gravity. Therefore, thought to be sexually selected 2. Small, narrow feet in women are also thought to be a result of sexual selection because it is not beneficial especially during pregnancy. However, it is a true indicator of age d) Given that sexual selection appears to have shaped human female morphology, explain how aspects of human reproduction have altered the general pattern addressed in (a). Human reproduction has altered the general pattern addressed in (a) because of the benefits of monogamous mating for both sexes. Human men will benefit from investing in a female mating partner “for the long run”. Since in an essentially monogamous society, the variance in female and male reproductive success is equal, assuming an equal number of men to women, it is beneficial for the male to invest early in the female. Therefore, when a male is looking for a mate he looks for cues of youth that indicates greater potential to produce offspring. The need for females to display honest signs of youth have pressures the sex to develop morphological cues. e) Two different processes have been proposed as explanations for how sexual selection could produce a wide variety of traits that do not enhance the chances of survival. Name and describe each of these processes, and explain how they differ from one another. Get better definitions
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finalstudyguide - 1. a) Across species, sexual selection...

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