science

7 rules that explain Earth's most extreme animal shapes and sizes


Animals come in extreme shapes and sizes, from enormous elephants and colossal squids to miniature marmoset monkeys and teeny-weeny frogs. But there is some method to nature’s madness, and while evolution can be unpredictable, there are a few established rules that govern how animals take these extreme shapes.

Below are seven rules that scientists have established to describe evolutionary trends. Keep in mind that these are general trends, and not every species is covered. Even nature’s rules are made to be broken.

Bergmann’s rule

A polar bear walking through the Arctic National Wildlife Refuge in Alaska.  (Image credit: Patrick J. Endres via Getty Images)

Bergmann’s rule states that animals evolve to be larger in colder climates. This trend occurs because larger animals have a smaller surface area-to-volume ratio, which helps to reduce heat loss. Thus bigger bodies are better at retaining heat compared to smaller bodies.



READ SOURCE

This website uses cookies. By continuing to use this site, you accept our use of cookies.