BIO 1130 Lecture Notes - Lecture 8: Plant Hormone, Chorionic Villi, Osmoregulation

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Adam Brown

Document Summary

The naked ape: primates have become hairlessness over evolutionary history. Mammal hair: used for thermoregulation, protection (abrasion, sunlight, parasites), camouflage themselves, species recognition and social communication. Hairless mammals: large mammals (elephants) that live in hot environments do not have hair as a thermal adaptation for heat dissipation. Climate change: around 3mya, cooling of the atmosphere lead to reduced precipitation, shrinking of forests causing the trees to leave our ancestors due to decrease in availability of food sources and scarcity of water holes. On the hot savannah: travelling over distances became a danger because of overheating, particularly in the brain. Mammal vs. human skin: sebaceous glands (abundant) shed heat because of the saturated fur: mammals: density of eccrine sweat glands focus water on bare skin (2-5m in humans). Homo ancestors: australopithecus were arboreal in tropical forests since they were capable of bipedalism. Their diet of fruits, leaves and tubers made them have a sedentary (easy) lifestyle.