AnthNotesExamTwo - ANTH LECT TEXT NOTES: CHAPTER 16 and 17...

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ANTH LECT TEXT NOTES: CHAPTER 16 and 17 CHAPTER 16: THE BIOLOGY OF MODERN HOMO SAPIENS There are three principle mechanisms that bring about variation among individuals and populations: 1) Nongenetic means of coping with the environment called adjustments: Behavioral adjustments are cultural responses to environmental stress, acclimatory adjustments are reversible physiological responses to such stress, and developmental adjustments are alterations in the pattern of growth and development 2) Microevolutionary change or adaptation 3) Genetic differences in the processes of growth and development HUMAN ADAPTIBILITY: ADJUSTMENTS One reason that the human species survives in a wide diversity of habitats is nongenetic changes termed adjustments >>>Behavioral Adjustments --BA’s are cultural responses to environmental stresses. --Nongenetic, may be continuously altered to meet new environmental situations --Example: housing: igloos --It is through all aspects of technology that people can survive under difficult environmental conditions. Acclimatory Adjustments --Reversible physiological changes to environmental stress >>>Artic Habitats -- Hypothermia : Lowered body temperature induced by cold stress --Normal body temp averages 98.6 ° The ability of the hypothalamus of the brain to control body temperature is impaired when the temp falls below 94 ° ; Temp-regulating ability is lost at 85 ° , may result in death -- Critical Temperature : The body must begin to resist a lowering of body temperature; occurs in the nude human body at 87.8 ° --Two short-term methods of producing additional body heat are exercise and shivering -- Vasoconstriction : Constriction of the capillaries in the skin in response to cold temperatures that prevents much of the warm blood from reaching the surface of the body where heat could be lost -- Basal Metabolic Rate : Maybe the most important acclimatory adjustment; The measure of the total energy utilized by the body to maintain those body processes necessary for life; the minimum level of heat produced by the body at rest—25% in adults, 170% in infants >>Desert Habitats --In some ways humans are better able to survive in the hot and arid climates of the world than in the Arctic—ability due to general lack of body hair (insulting material) --Four losses of body heat : 1) Conduction : Them movement of heat from one object to another by direct contact 1
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ANTH LECT TEXT NOTES: CHAPTER 16 and 17 2) Convection : The warm object is surrounded by a cooler fluid; Movement of heat from an object to the surrounding fluid, either gas or liquid; heat causes the gases and fluid to move away from the object; Currents set up in the air carry away heat 3) Radiation : Electromagnetic energy that is given off by an object 4) Evaporation : Liquid is transformed into a gas-utilized energy; When water is turned from a liquid to a gas (water vapor) a certain amount of energy, in the form of heat, is required (think swimming) --In temps above 95 ° body heat is lost mainly thru
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AnthNotesExamTwo - ANTH LECT TEXT NOTES: CHAPTER 16 and 17...

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