Lecture 10 Outline of Last Lecture I. Macroevolution and Microevolution Outline of Current Lecture II. Modern Human VariationA. Is variation random?B. RaceCurrent LectureHumans - Homo sapiensUnderstand variation:Produced through genetics, gene expressionProduct of '4 forces' (mutation, gene flow, genetic drift, natural selection) ANTHRO 1031st editionMicroevolution (evolution within a species)Human cultureNatural selection patterns variationIs variation random? -NoEx: Is sickle cell anemia a random variation? -No, it is found in places with malaria. This is understandable in biological terms.Human culture - Ex: lactase persistence -> dairying communities drank moremilk and developed lactase persistenceTay-Sachs allele - found in Quebec, Pennsylvania, Louisiana, Eastern EuropeThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.There is a frequency - genetic drift, founder effectClinal variation - environment changes graduallyEx: Cerumen (ear wax) - two phenotypes, dry and wet96% of dry ear wax in Asia, declines to 10% frequency in middle eastVariation is clinal (gradual change)Note: There are not people between Asia and the Middle East with partially wet but partially dry ear wax because there are only 2 phe-notypes.Result of genetic drift (founder) - people movedSkin color: You can measure percentage of light reflected from someone's skinDark skin absorbs light, light skin reflects light If all 7 billion people lined up according to skin color, we could not divide them saying they are different races. There would be one skin tone differ-ence between the people on the border of two "races".Rangifer tarandus (italics): Caribou and reindeer sub-species: 70% of tiny ge-netic variation is between subspeciesHomo sapiens: Less than 10% of tiny human genetic variationHuman race is not biologyVariation is clinal; race is disjunctTraits are discordantRace implies you can tell things about a person based on their race - their hair type, color, etc. - this is wrong.More variation within 'populations' vs. between 'populations'population thinking vs. essentialismPeople within a race are more genetically different from each other than theyare from someone from a different "race"Evolution - change is the norm; race is not permanentYou did not inherit your "race" from your parents. Your "race" has changed over time.Human race is not biology (skin color is biology, but clinal)However... Human races exist and are importantHuman races are cultural categories (sharply defined, not clinal)We decided what race isEx: Obama - half black and half white? Multi-racial? Self identifiesas an African American, though his mother is a white AmericanRace affects our biology, well-beingAffects our wealth, % of children in
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