Evolution of Sexuality Review Exam 1 Thursday September 26th Essays Choose 1 out of 2 Relationship between food and mating systems o Food is needed to sustain for growth and development cell repair o Diet must satisfy energy requirements provide nutrients and and for reproduction minimize exposure to toxins o Smaller animals need small amounts of high quality food large animals value quantity over quality o Food distribution affects ranging patterns Ranging patterns affect grouping patterns and thus social organization and mating systems Female ranging patterns map onto the food in the environment Males ranging patterns map into the females o Territoriality Relationship between male to male competition and female choice o Sexual selection is the struggle by one sex for mating with another o Intersexual Selection Female choice Choose most beautiful correlates with good genetics good genetics give the offspring best chance for survival Female choice favors Traits that directly increase fitness of female Traits that indicate good genetics fitness of offspring Traits that are nonadaptive but conspicuous o Intrasexual Selection Male to male competition Body size dimorphism Canine size Testes size sperm competition Intensity of competition is hard to measure Commonly believed that male mating competition results in increased sexual dimorphism o Females are expected to be more choosy and males more competitive during fertile periods o Bateman s Answer Females are choosy because eggs are large expensive and scarce More females enhance a male s reproductive success but more males do not increase a female s o Female female competition occurs when males are scarce or provide something valuable o Triver s Amendment Whichever sex invests more in the offspring should be choosier o Infanticide Short Answers Choose 3 out of 4 Sexual Dimorphism o The strong selection pressure that makes males bigger than females o Usually occurs when there is strong competition for mates o Body size and canine size Good in fights o Testes size Sperm competition Sex ratio is predictive o Reduced sexual dimorphism Less intrasexual selection More balanced operational sex ration with increased population levels Red Queen Hypothesis o It takes all the running you can do to keep in the same place o Leigh van Valen o With sex each offspring is different from their parents and each other so pathogens must begin anew each generation o Bet hedging Diversity the principle behind investment for the future By only passing on 50 of your genes you are betting that more of your offspring are going to survive Handaxe o Indicator of sexual selection o Kohn and Mithen 1999 o Ability to construct a beautiful handaxe is being selected for Largest and most symmetrical impress females Explains minimal wear and variation Variation is an indicator of male ability good genes o For this to work hominins must Be attracted to symmetry quality of manufacturing must be heritable heritable quality must be a sign of fitness female choice was based on handaxe quality Human Mating System o Foragers o The amount of male provisioning determines the mating system Increased return rates by certain hunters results in increased pair bonds If food is shared benefit is lost o When provisioning is less important females should pay more attention to Pathogen protection Gene shopping Results in increase in polygyny o Women value male provisioning less where males bring in less food which results in greater polygyny Multiple Choice 25 Questions Chapter 1 Anthropology is the study of humans Subfields of anthropology o Archeological past societies and cultures o Cultural cultures and societies o Linguistic language o Physical biological human evolution and variation The evolutionary theory tries to explain human biology through evolution and natural selection Naturalistic Fallacy is the error of deriving what ought to be from what is Genetic Determinism is the idea that behavior is unalterable and unchangeable Sexuality is o How people experience and express themselves as sexual beings o Biologically it can encompass sexual intercourse and contact o Sociologically it can cover cultural political and legal aspects o Philosophically it can contain moral ethical and theological aspects Prehistory sexuality is represented in art and symbolism The Greeks were one of the few major civilizations to institutionalize homosexuality pederasty The Romans viewed sex and marriage socially and economically Kama Sutra is a guide to sex love and family The Moche from Peru created sex pottery Christianity outlined natural and unnatural sexual acts Islam shared Jewish and Christian roots along with Arab tribal beliefs In the Victorian Era sexuality became more conservative in public but in private they were not pornography adultery prostitution The Comstock Act of 1873 prohibited the mailing of obscene lewd lascivious and indecent writing or advertisements Social Hygiene Movement o Women were catching STDs from husbands who frequently used prostitutes Sexology o Blood tests before marriage and police action against prostitutes o Alfred Kinsey sex more important than originally thought o Masters Johnson studied physiology of sexual response A theory is a set of assumptions principles or methods that helps a researcher understand the nature of a phenomenon being studied o Evolutionary perspectives Biological theory biological process Evolutionary psychological theory environmental influences Sociobiological theory natural selection o Psychological theories Psychoanalytic theory ego superego libido Cognitive theory thoughts behavior Social learning theory conditioning reward punishment o Sociological perspectives Symbolic interaction theory prior learning Reiss theory kinship power Natural Selection is the primary explanation of sex and sexuality sexual selection is driven by the instinct to pass on genes o Variation among individuals o Competition for survival and for mates o Favorable traits survive and get passed down Adaptation is the evolutionary process whereby a population becomes better suited to its habitat Fitness o Reproductive success o Intraspecific within a species o Interspecific between two species Chapter 2 Strategies o Maximize reproductive success Males mate with every female possible without getting hurt from other males Females mate with the most fit male Strump and Boesch o Females are expected to be more choosy and males more competitive during fertile