ANTH 120 1nd Edition Lecture 27Current LectureBiology in the Present: Living People1. What are the four types of adaptation?a. Geneticb. Developmental (Ontogenetic)c. Acclimatization (Physiological)d. Cultural (Behavioral)2. Is race a valid biologically meaningful concept?3. What do growth and development tell us?Adaptation: Meeting the Challenges of LivingFour Levelsa. Geneticb. Developmental (Ontogenetic)c. Acclimatization (Physiological)d. Cultural (Behavioral)Heat and Cold Selective Pressures- Hot Temperature: Body overheats, water loss: Hyperthermia- Cold Temperatures: Body heat loss, frostbite: HypothermiaGenetic Adaptations to Climate- Cold Environments:o Increase body mass, volumeo Shorten limbso Surround vital organs in fat- Hot Environments:o Decrease body mass, volumeo Elongate limbso Decrease amount of body fatCultural Adaptations to Cold TemperaturesThese 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.- Thick or layered clothing- High calorie fatty foodsPhysiological Adaptations to Climate- Vasoconstriction- blood closer to internal side to surface of the skin, keeps heat closer to body to stay warm- “Goosebumps”  traps a layer of heat or warm air around your skin- Vasodilation  (Hot Climate) heat loss across epidermis, dilation of blood vesselsFunctional Adaptations  occur over an individual lifetime- Developmental (Ontogenetic)- Acclimatization (Physiological)Is race a valid, biologically meaningful concept?Debunking the Race Concept- Johann Freidrich Blumenbacho Typological classification 5 fixed races by skull shape- Monogoloids- Malays- Ethiopians (Africans)- American Indians- Caucasoids- Franz Boaso Biological Variationo Skull shape changeso Behavior determine by culture- R.C. Lewontino Genetic (DNA) variation does not follow racial categorization- Geographical Clineso Gradual change in a phenotypic character from one population to anothero High frequencies of a trait on one end and decreasing on the other end- Gene Flow (admixture)  spread of genetic material between populations- Cline: a gradual change in a phenotypic character from one population to anothero Close to the equator = darker skin colorIntegumentary System: The Skin an Organ System- Skin, hair, nails, glands- Functionso Prevents dehydration and injuryo Defense against microorganismso Vitamin D synthesiso Protect against UV damage- Epidermis (top layer) and Dermis (thicker layer of skin)- Cells that make up the skino Keratinocytes Majority of skino Melanocytes Octopus, nucleus with arms that cover over the other keratinocytes Responsible for producing melanin a pigment in skin and hairo Melanin Function: protect nucleus from UV radiation Amount and type of melanin is genetically determined Skin color is a polygenic (multi gene) trait- Quantity, type and distributiono Eumelanin: group of dark brown, almost blacko Pheomelanin: group of reddish and orange- Many genes (polygenic) determine an individuals skin color by controlling the amount of melanin synthesized- More melanin = darker skin | Less melanin = lighter skin - Skin Color follows a geographic cline Gloger’s Rule  decrease sunlight = decrease skin pigmentation, increase in sunlight = increase skin pigmentationSelective Pressures1. UV light initiates Vitamin D Synthesis2. UV light protectiona. Rickets and Melanoma Low sunlight = low UV light Maximizes vitamin D synthesis by decreasing melanin productionHigh Sun = High UV radiation Decreases skin damage produce more