Apes are not monkeys, and all monkeys are not the same. When primatologists’ describe a type of monkey, they begin by defining it as an Old World or New World species. As the name suggests, the Old World monkeys are those found throughout Europe, Africa and Asia while the so called New World varieties are restricted to the Americas. DNA evidence strongly suggests that the old and new world species are derived from a common ancestral stock that diverged about 40 million years ago. With an ocean separating the two populations, each variety evolved in response to their respective habitats. Forty million years later, there are now 78 species in old world and 53 in the new.
Geographic isolation and environmental characteristics are responsible for some of the key differences between the two groups. Monkeys found in the Old World tend to be larger than those in the new. New World varieties are entirely arboreal and many have prehensile tails that allow them to move throughout the dense forest canopies found in the American tropics. In contrast, many Old World species are as comfortable on the ground as they are in trees. Found from the deserts of Ethiopia to the snow-capped mountains of Japan, Old World monkeys have adapted to a variety of habitats. Other anatomical differences include an opposable thumb and trichromatic vision throughout the Old World, compared to a thumb in line with fingers and dichromatic vision in the new. When faced with the choice of new or old, one just needs to look at the face. The flat-faced Platyrrhines are found throughout the Americas while the narrow-nosed Catarrhines with their downward faced nostrils are found in the Old World.
©2000-2015 BTLeventhal.com / Bruce & Tamy Leventhal. All rights reserved. No image on this site may be used without permission.