BIOL 111 Lecture Notes - Lecture 20: Thermoregulation, Keratin, Convergent Evolution

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: All

Document Summary

How to get into the air: feathers, better lungs, lighter bones. The ancestor to birds was probably a theropod dinosaur. Archaeopteryx early bird developing from therapod dinosaurs. 4-chambered heart (completely separate pulmonary and systemic circuits) Most fly but there has been a lot of loss of flying ability. Diverse beaks diverse diets (carnivorous, herbivores, nectivores) Different birds show multiple types of beaks. Relationship between radiation, evaporation, conduction and convection. Source of body heat: ectotherms: absorb external heat, endotherms: generate their own internal heat through metabolic processes. Work with heat recognition recognize endotherm organisms because they are the ones generating energy mammals, bees, etc. Metabolic rate increases when the organism is warmer temperature dependent activity and metabolic rate. In the field, a lizard actually maintains body temperature at a different temperature than its environment. Behavioral thermoregulation: a lizard maintains its body temperature between upper and lower limits by moving between hot and cold microhabitats.