Understanding Evolution and Classification

What are haplorhines?

Anthropoidea + Tarsiers

What are strepsirhines?

lemurs and lorises

What is divergent evolution

The process by which two or more species become increasingly different due to the environment

What is convergent evolution

Unrelated species become more and more alike due to environmental factors. They appear to have similar traits but that is NOT due to shared ancestors

What are primitive traits

Traits that came from mammals, what makes mammals mammals; warm blooded, live young, feed young with mammary glands

What are derived traits

newly evolved features; grasping foot, nails, increase in brain size, forward rotation of eyes for stereoscopic vision

What are derived traits of prosimii

Tooth comb, bottom teeth look like a come; long nose that is wet at the end; post orbital bar only, eye is not fully enclosed in bone

What are derived traits of anthropoids

Hairy nose rather than a wet nose; mobile upper lip; reduction in facial length; nearly complete bony eye sockets

What are derived traits of Platyrhinni

Nostrils face laterally; 12 premolars in adult dentition, 2-1-3-3; Some have prehensile tail

What are derived traits of Catarhinni

Downward facing nostrils; 8 permanent molars

What are derived traits of Hominoids (Apes and Humans)

Larger brains than monkeys; no tails; broad chests; long arms with mobile wrists, elbows, and shoulders

Derived traits of Hominin

- bipedalism

- larger brain size

- more complex behavior

- eyes capable of sharp 3d vision in color

What is sexual dimorphism?

distinct difference in size or appearance between the sexes of an animal in addition to difference between the sexual organs themselves.