The Meaning, Mechanism, And Evidence Of Bergman’s Rule Essay Example for Free

The Meaning, Mechanism, And Evidence Of Bergman’s Rule Essay The publication of Charles Darwin’s â€Å"Origin of Species† was the turning point for nascent evolution theorists. Basically, he stated that organisms evolved into genotype or specie that breeds progenies which possess attributes of fitness, survivability, and adaptation to their environment over that of another of a related specie. This results to new generations becoming better adapted to their environment and more likely to survive than those that are less adapted, and this difference is not due to chance (Rittner and MacCabe, 2004, p. 241). Christian Bergmann, A contemporary of Darwin published a paper which embodied his Bergmanns rule that correlates latitude with body mass in animals. Broadly it asserts that within a species the body mass increases with latitude and colder climate and decreases with warmer climate. The difference in size makes this a better adaptive strategy in the climatic environs these species are found. The Mechanism of Determining Bergman’s Rule Christopher Ruff of the John Hopkins University has conducted studies on variation of humans in to climate. To make it simple, Ruff views the human body as a cylinder, the diameter of which represents the width of the body, or, more specifically, the width of the pelvis; the length of the cylinder represents trunk length. The link between anatomy and climate relates to thermoregulation, or the balance between heat produced and the ability to dissipate it. This relationship translates to the ratio of the surface area to the volume of the cylinder, or body mass. In hot climates, a high ratio that is, a large surface area relative to body mass, or a slim, long trunk a facilitates heat loss. In cold climates, a low ratio that is, a small surface area relative to body mass, a bulky, short trunk allows heat retention. Differences in body breadth among human populations largely explain differences in body mass, the basis of Bergmann’s rule (Lewin, 2005, p. 69). Ruff’s scientific studies could be summed as follows: on the relationship between body breadth and latitude, Ruff concluded that people living at high latitudes have broad bodies, as measured by the bi-iliac (pelvic) breadth; those residing at low latitudes have narrow bodies; on the relationship between the ratio of surface area to body mass and latitude people living at high latitudes have a low ratio as a consequence of Bergmann’s rule; and an increase in the length of the trunk has no effect on the ratio of surface area to body mass.