Different Yet Complimentary :: essays papers

Different Yet Complimentary Even though the Bergmann rule and Allan rule are different rules entirely they are both complementary to each other. In 1847 Bergmann observed that within the same spices of warm-blooded animals, populations have less bulky individuals are more often found in warm climates near the equator while, those with greater bulk, mass, are found further from the equator in colder regions. This is due to the fact that big animals generally have larger body masses that result in more heat being produced. The greater amount of heat results from there being more cells. A normal by product of metabolism in cells is heat production. Subsequently the more cells an animal has, the more internal heat it will produce. In addition, larger animals usually have smaller surface area relative to their body masses and therefore are comparatively, in efficient at radiating their body heat off into the surrounding environment. This is illustrated when the volume increases twice as fast as the surface size. Rel atively less surface area results in relatively less heat being lost. In 1877, Allen went further than Bergmann in observing that the length of arms, legs, and other appendages also has an effect on the amount of heat lost to the surrounding environment. He noted that among warm-blooded animals, individuals in populations living further away from the equator in colder environments. This is due to the fact that a thin body with relatively long appendages is less compact and subsequently has more surface area. The greater the body area, the faster body heat will be lost to the environment. A tall and slender individual will have the same volume but greater surface area. It is comparable to an animal with arm and legs. I will demonstrate to you in this essay that even though the Allan rule and Bergmann rule are two different rules they are also complementary to each other. I will show this through explaining each on thoroughly, compare and contrast them and by presenting examples for e ach rule. Carl Bergmann was a 19th century biologist who pointed out that amongst birds and mammal individuals of the same species tend to be larger and heavier when they lived in colder climates. This applies to pumas, bears, koalas, penguins, etc. Even in the case of people, there is an obvious difference between the height and weight of a high-latitude Scandinavian and those of an equatorial pygmy.