Question

How does having a small surface area to volume ratio minimize heat loss in polar bears?

Answer 1

Hint: Bergmann’s rule is an ecological rule that states how the distribution of animals occurs depending on the climatic conditions of a geographical area. It states that areas with colder climates are inhabited by animals with larger bodies and shorter appendages such as the polar bears.

Complete answer:
Metabolic processes occurring in our body produce heat in the body. This heat is lost from the surface of the body of organisms. Animals adapt to the climatic conditions of the area they inhabit for better survival. This was better explained by Carl Bergmann in 1847 who said that the endothermic mammals and birds with larger bodies tend to occupy areas with cold climates.
Larger animals have a lower surface area to volume ratio than smaller animals, so they radiate less body heat per unit of mass, and therefore stay warmer in cold climates. This is the case with polar bears. For animals in warmer climates, body heat generated by metabolism needs to be dissipated quickly rather than stored within. Thus, the higher surface-area-to-volume ratio of smaller animals in hot and dry climates facilitates heat loss through the skin and helps cool the body.

Note: Although we can explain the minimal heat loss in polar bears because of having a smaller surface area to volume ratio by Bergmann’s rule, many other factors influence body size. These factors are the availability of food and other resources and the effect of predation on the organism.