What is the Bergmann rule?

Bergmann's rules are a theory that states that animals will tend to be greater in higher latitudes than they are in the equator, and correlate average temperatures with the body size. This principle is one of the families of "ecogeographic rules", the theory that biologists have given to explain natural phenomena based on ecology and geographical location. Bergmann's rule is not without controversy, not least, because there are some remarkable exceptions that would seem to refute the rule, such as a massive African elephant.

The idea of ​​Bergmann's rule is that the lower ratio of body mass to the surface surface, and less heat loss, and experience the animal. The greater the ratio, the more heat loss will be experienced. In regions such as Arctic, animals naturally want to reduce the amount of heat that lose to become hypothermic and do not die. On the other hand in the equatorial regions, animals want to lose heat so that they do not rotate hyperahermic and suffer from the related ZdraVoto complications. And the general rule, equatorial animals should be smaller, while the arctic animals should be more appropriate.

There is evidence that supports Bergmann's rule: for example, polar bears are much larger than magnificent bears who live closer to the equator, and many animals develop size change in both species and closely related species that can correlate with geographical location. Bergmann's rule was also used to explain the typically heavier types of body of people from Arctic regions compared to equatorial nations.

However, the dunner also emphasize that the conrapoity to Bergmann's rule. For example, some Polynesian nations have great body structures and tendency to overweight with age, although they live in warm climate and some arctic animals are relatively small, while some equatorial creatures are growing greatly. Most likely to be beRgmann's rules just one of the large family of factors that can affect the size and development of creatures on Earth, and although it is something to be taken into account, it is not a hard and rapid explanation for a wide range of body, shape and size dispersion.