Thursday March 10 y Human Sexuality Exam 1 History Four fields of anthropology Cultural Archeology Linguistic Physical Evolutionary Theory explains human biology through evolution natural selection Naturalistic Fallacy error of deriving what should be from what is Genetic Determinism Idea that behavior is pre set and unchangeable wrong Sexuality How people express themselves as human beings components Biologically intercourse and sexual acts Sociologically cultural political legal aspects Philosophically moral ethical religious aspects Past Cultures Sex Hebrews had bible that outlined rules and told tales of misconduct Greeks Free and open about sex Romans few restrictions about sexuality means to improve socioeconomic life Indian Patriarchal Karma Sutra a guide to pleasing spouse raise a family Chinese Tao yin yang sex is strictly procreative Islam drew from christianity and judaism strong rules of modesty Moche used pottery to express themselves before writing Jesus was liberal about sex St Paul is the one to deny sexuality The Reformation 1 Thursday March 10 y Martin Luther Sex is blessed within marriage but females are subjective John Calvin men and women are partners in everything Victorian Era Sexuality very taboo in public but free and open in private 19th century Medical model of sexuality Comstock Act no mailing obscenity 20th century Hygiene movement Sexology Flapper Era Feminism birth control sexual satisfaction Gay Liberation The Origins of Sex Primary explanation is Sexual Selection the goal is to pass genes to next gen Sex Process of combining genetic traits through sex cells called gametes allele one of two or more forms of a DNA sequence of a particular gene Genotype genetic constitution of an organism w reference to a specific character Phenotype an observable characteristic that develops after birth depending on an environment gene environment Meiosis cell division that produces reproductive cells in sexually reproducing organ Recombination Gene Mixing is why we all look different Natural Selection Competition for survival those w favorable traits survive and re produce therefore passing favorable traits on to the next generation Adaptation evolutionary process where a population becomes better suited to its habitat structural physical change behavioral ability to learn isms 2 Law of Segregation parental genetics are split evenly to offspring Red Queen Hypothesis with clones pathogens can attack effectively and exploit genotype kill every member With sex pathogens must begin anew each genera Thursday March 10 y tion Strategies of the sexes females as possible vest in Male gametes sperm are small numerous and cheap they mate with as many Female gametes egg are large rare and costly they pick the best male to in The costs of sex includes injury being eaten STD s breaking successful genes Theory a set of assumptions principles or methods that helps a researcher under stand the nature of a phenomenon being studied Biological theory sexual behavior is a biological process Sociobiology sexual behaviors are a result of natural selection in evolution Evolutionary psychology sexual behaviors are a result of psychological mecha nisms and environmental influences Social learning theory reward punishment conditioning Cognitive theory our thoughts are responsible for our behaviors Sexual Selection Inter Sexual Selection Female Choice Females choose most beautiful males decorate polygyny 3 3 favorable traits directly increases fitness of female indicate good genetics and are nonadaptive but conspicuous Mate choice behavior can come in form of active solicitation refusal to males or Thursday March 10 y subtle signs with low rank and age Females with high rank and age have better success refusing males than those most choosy while ovulating have sex with alpha males during ovulation Intra Sexual Selection Male Male Competition Sexual Dimorphism is the difference in size between a male and a female of a species Usually happens where there is polygamy and males must defend fe males Dimorphism is determined by operational sex ratio where there is 5 females one large male is enough to defend the more females there are the more males there must be and the smaller they will be Less male male competition leads to less dimorphism Triver s Amendment whichever sex is more invested in offspring will be choosier except for primates because females are always invested Infanticide Male primates kill infants they believe not to be theirs so females mate with every male to confuse paternity Sperm competition it pays to have better sperm so that the male is actually the one to impregnate the female Mostly in multi male multi female groups Sexual selection in Hominins pair bonding dimorphism much less 1 2 1 Australopithecines our ancestors who had a large degree of dimorphism 4 Handaxe tool made thousands of times over but with no use or signs or wear Maybe to attract partners Movious line no hand axes in east asia Thursday March 10 y genitals fully structured at birth but not functional release of eggs and sperm yet Sexual Characteristics Primary characteristic is the genitals Male Penis and testes Female Vagina cervix uterus and ovaries Early child development 2 5 yrs begin exploring their bodies asking what is a boy girl do not yet understand sexual behavior Middle child development 6 12 yrs genitals grow with the rest of the body sexual behavior becomes more private changing in private begin asking about sex too smart for stork Male Puberty change in genitals Female puberty 5 size of testes and scrotum rapidly increase sperm production begins testosterone main catalyst eggs ripen and period first sign of reproductive ability Thursday March 10 y First Menses the heavier a women the earlier she menstruates race african american girls 12 caucasian girls 13 in the hadza culture females do not menstruate until age 16 or 17 because of a lack of nutrition Secondary characteristics physical traits that distinguish male and female Male secondary characteristics include hair body before facial hair line changes face shape changes voice drops body increases in size and strength Female secondary characteristics include hair pubic region first breast develop ment using tanner stages to measure pelvis hips broaden Girls start and finish puberty earlier but boys grow bigger Biologically an adult when you can procreate males ejaculate females menstruate Socially transition into an adult through puberty