1. 12.6 Primate Evolution
How did modern humans evolve?

2. KEY CONCEPT Humans appeared late in Earth’s history.

3. Humans share a common ancestor with other primates.
Common ancestor of all primates probably arose before the mass extinction that ended the Cretaceous Period.
Primates are mammals with flexible hands and feet, forward-looking eyes and enlarged brains.

4. Primates evolved into prosimians and anthropoids.
Prosimians are the oldest living primates.
They are mostly small and nocturnal. (lemurs)
These are the tarsiers.
Their physical appearance
has changed little since their
appearance 40 MYA.

5. Anthropoids are humanlike primates.
They are subdivided into the New World monkeys, Old World monkeys, and hominoids.

6. New world monkeys are native to the Americas.
Live in trees
Have grasping tails

7. Old world monkeys are native to Africa.
spend some time in trees, but spend much of the
time foraging on the ground
They have larger brains and can grasp things better.

8. Homonoids are divided into hominids, great apes,
and lesser apes.
Homonids include living and extinct humans.

9. Homonids walk upright, have longer lower limbs, opposable thumbs, and large brains
Include all species in the human
lineage, both modern and extinct.
The skeletal changes required
to walk upright can be seen in
intermediate fossils between
homonoids.

10. Bipedal means walking on two legs.
Walking upright has important adaptive advantages.
foraging
carrying infants and food
using tools

11. There are many fossils of extinct hominids.
Most hominids are either the genus Australopithecus or Homo.
Australopithecines were a successful genus.
The Homo genus first evolved 2.4 million years ago.

12. Modern humans arose about 100,000 years ago.
Homo sapiens fossils date to 100,000 years ago in Ethopia.
Human evolution is influenced by a tool-based culture.
There is a trend toward increased brain size in hominids.
Australopithecus
afarensis
Homo habilis
Homo
neanderthalensis
Homo sapiens