Size and Animal Biology:

Size affects the morphology, physiology, life history, ecology of animals. Further, these parameters are all interrelated with one another. Below is a table which contains some of the derived allometric equations which relate particular attributes to body size. Recall the allometric equation is in the form Y= a*M^b where a is the intercept and b the slope of the log transformed data. The constant a is generally important when comparing different groups - for example mammals and reptiles or herbivores and carnivores. The slope is generally examined to see if the factor being examined increases or decreases as body size increases and in what manner. As a point of reference if b = 1 then if the body size doubles then the parameter being predicted by the equation doubles. For example when b is greater than one when examining a morphological like femur mass would indicate that the femur represents an increasing proportion of the total body mass as size increases. Reviewing the data below clearly illustrates the profound influence of size on the biology of organisms.