Allen's Rule: Relation Between Limb Length And The Environment

1877 Allen’s Rule An American zoologist Joel Allen discovered the relation between limb length and the environment that a population lives in (Larsen 2017, pg,115). This rule stated, “The principle that an animal’s limb lengths are heat-related; limbs are longer in hot environments and shorter in cold environments” (Larsen 2017, pg 115). Furthermore, Allen’s rule states that heat-adapted mammal populations will have long limbs, which maximize the body’s surface area and this promotes heat dissipation (Larsen 2017, pg 115). Similarly, cold-adapted mammal populations will have short limbs, which minimize the body’s surface area and this promotes heat conservation (Larsen 2017, pg 115). By studying different populations and their relation to the equator, Allen was able to develop this scientific breakthrough. This scientific breakthrough is similar to Bergmann’s rule that was discovered in 1847. Allen’s breakthrough allowed scientists to find an understanding between environments and populations. This is important because it allowed scientists to find advantages and disadvantages between certain populations and their environments, and to identify the adaptations that occurred between populations (Larsen 2017, pg 115). Allen’s rule provides part of an explanation in
Mendel noticed that the linked traits had a possibility of separating, however only a certain few would undergo this process. As the traits separated Mendel discovered that the traits went through a process, which was later named recombination. There is one step prior to recombination, which is a cross-over event. This event was when, “a homologous chromosome wraps itself around another and then exchange genetic information during meiosis” (Larsen 2017, pg 54). From this event recombination takes place, “the exchange of genetic material between homologous chromosomes, resulting from a cross-over event (Larsen 2017, pg