BIOL 3753 Lecture Notes - Lecture 3: Arctic Circle, Crypsis, Adipose Tissue
Document Summary
Anatomical the structures of the body what is where and what they look like. Behavioral the manner in which animals move and act. Reduce thermal conductance (how much heat is lost from body) Reduce thermal gradient from body to environment (minimize exposure of systems to heat loss) Bergmann"s rule within a taxonomic group, organisms of larger size will be found in colder climates a smaller sa : volume ratio. This rule only applies to a certain point right around 60 degrees north (right below the arctic circle), the trend begins to go backwards. Around the poles, animals actually get smaller and this is because there is less sun and therefore less vegetation and less productivity without excess energy, it is impossible to grow large. Endotherms from colder climates have shorter limbs/appendages than those from warmer climates. Terrestrial endotherms populations in colder, drier climates have lighter pigmentation. Paler animals radiate less heat than dark ones.
