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PSY266 Exam II
PSY 266 Exam II
Question | Answer |
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Sexual Selection | Applies to those characteristics that provide individuals with advantages in gaining access to mates. |
Sexual Selection Explained | Why certain animals had elaborate displays that could potentially attract predators. Why males were sometime larger than females. Why the behavior of one sex would be more risky or use energy that could otherwise go toward gathering food or evading predat |
Intersexual Selection | Members of one sex trying to impress that of the opposite sex Using displays that could reveal them to predators and put them in harm’s way. |
Intrasexual Selection | Members of one sex competing for the right to mate with those of the opposite sex. Usually done by males. Have developed secondary characteristics and behaviors such as weapons to defend a territory or fight for control of a harem. Typically, the femal |
Sexual Dimorphism | Distinguishing characteristics between two sexes of the same species (i.e. size, weight, color, etc). o In humans, males have more upper body muscles, women have wider hips, and men tend to be taller. |
Parental Investment | The effort that each parent puts into raising their offspring. Females tend to put in more and are likely to be more choosey as a result. Put more energy in developing offspring, Put more energy in providing offspring necessary nutriment and protection |
Male adornment | Physical characteristics of males that shows they are healthy and are able to stay alive despite their ‘handicap.’ |
Fisher’s “sexy sons” hypothesis | Females look for males with the “sexiest” traits because it is more likely that those traits will pass on to their sons, making them “sexy” to other females. |
Good genes hypothesis | Male adornments shows females that the males have good genes. |
Zahavi’s handicap hypothesis | Males develop ornaments not to look attractive, but to show that they are capable of surviving despite their ‘handicap.’ |
Parasite hypothesis | Male adornments are signs that they do not have parasites, o Displays health rather than handicap. |
Advantages of sexual reproduction | There is variation within sexual reproduction and not asexual reproduction. o With variation, the species is more likely to survive if something catastrophic was to occur or the environment was to change drastically. |
Faster Evolution Argument | Organisms that reproduce sexually can evolve faster in rapidly changing environments. |
Muller’s Ratchet | In an asexual population, if a deleterious mutation were to occur, it would spread to all offspring. In sexual populations, there’s only a 50/50 chance. Sex helps to wean out harmful mutations. |
Raffle Analogy | Sex will be more common in highly unstable environments. o Not a sound theory, Some asexual organisms are able to live in very unpredictable places. |
Red Queen Theory | Parasites and their hosts are at constant evolutionary battle. o Arms Race, Parasites evolve much more rapidly than host The host produces variable offspring in response that will, by chance, develop a resistance. In species that can produce either |
Polygamy | Non monogamous behavior. |
Polygyny | One male with multiple females. |
Polyandry | One female with multiple males. |
Monogamy | One male with one female and vice versa. |
Polygamy and Monogamy’s relationship to sexual dimorphism | Sexual dimorphism is more apparent in species where a male protects an entire harem. Male gorillas have small testicles, but control large harems and are plygynous. Sexual dimorphism is unnoticeable in monogamous species such as the gibbons. They are t |