HLTC23H3 Lecture Notes - Lecture 5: Dibenzofuran, Akwesasne, Peroxidase
Document Summary
Bergman s rule: populations in colder climates are fenerally larger, with wider torsos/stockier stature, since reduced surface area relative to body weight limits heat loss. Allen s rule: populations in colder climates will have shorter arms and legs relative to height (to limit heat loss), while those in warmer climates will have longer arms/legs. Note: improved nutrition, particularly in tropical regions, is now reflected in weaker climate-body size relationships than in past. Temp: cold requires higher rate of basal metabolic rate and robs body of energy used for growth. Energy used to keep body alive instead of growth. Altitude: reduced oxygen hypoxia, high solar radiation, cold, low humidity, high wings, rough terrain. Limits life and agricultural productivity: hypoxia: most severe climatic stress. Less oxygen reach body tissues, can t be compensated by cultural or behavioural adaptions. Normal rbc saturated with oxygen 97%, at 3000 m, 90% only. Enough to disrupt cellular growth and metabolism.
