Question

plz.... gives five rules of Adaptation fir Thermoregulation????plz give ANSWER fastly plzzzzzzzzzz

Answer 1

Allen's rule is an ecogeographical ruleformulated by Joel Asaph Allen in 1877,broadly stating that animals adapted to cold climates have shorter limbs and body appendages than animals adapted to warm climates. More specifically, it states that the body surface area-to-volume ratio for homeothermic animals varies with the average temperature of the habitat to which they are adapted (i.e. the ratio is low in cold climates and high in hot climates).A contributing factor to Allen's rule in vertebrates may be that the growth of cartilage is at least partly dependent on temperature. Temperature can directly affect the growth of cartilage, providing a proximate biological explanation for this rule. Experimenters raised mice either at 7 degrees, 21 degrees or 27 degrees Celsius and then measured their tails and ears. They found that the tails and ears were significantly shorter in the mice raised in the cold in comparison to the mice raised at warmer temperatures, even though their overall body weights were the same. They also found that the mice raised in the cold had less blood flow in their extremities. When they tried growing bone samples at different temperatures, the researchers found that the samples grown in warmer temperatures had significantly more growth of cartilage than those grown in colder temperaturesBergmann's rule and Allen's rule played important roles in mid-twentieth century discussions of adaptation, variation, and geographical distribution. Although inherited from the nineteenth-century natural history tradition these rules gained significance during the consolidation of the modern synthesis as evolutionary theorists focused attention on populations as units of evolution. For systematists, the rules provided a compelling rationale for identifying geographical races or subspecies, a function that was also picked up by some physical anthropologists



There are two primary responses to fluctuating ambient temperatures (TA) exhibited by animals: poikilothermy and homeothermy (Figure 1). Because poikilotherms lack the physiological means to generate heat, the body temperature of these animals tends to conform to that of the outside environment in the absence of any behavioral intervention. Examples of poikilotherms include the "cold-blooded" animals (Kearney et al. 2009), such as most fish, amphibians, and reptiles. On the other hand, homeotherms have specific physiological adaptations for regulating their body temperatures; body temperatures of homeotherms do not fluctuate as much as those of poikilotherms. Indeed, all homeotherms maintain high body temperatures in the range of 36 to 42oC (Ivanov 2006) and include the "warm-blooded" animals, such as birds and mammals.