Chapter 6:

Adaptations over Time

7th Grade Life Science

CHAPTER 6: SECTION 3

EVOLUTION of PRIMATES

I. Primates

A. Humans, monkeys, and apes belong to the group of

mammals known as primates.

1. All primates have opposable thumbs, binocular vision, and

flexible shoulders that allow the arms to rotates.

2. These shared characteristics indicate evolution from common

ancestors.

B. Opposable thumb allows us to grasp and hold things

with our hands.

1. Tree dwelling primates can hold on to branches.

C. Binocular vision permits judgment of depth or distance

with eyes.

I. Primates

D. Primates are divided into two major groups.

1. Strepsirhines: includes lemurs, and tarsiers (See figure ).

2. Haplorhines: includes monkeys, apes, and humans.

I. Primates

E. Hominids

1. About 4 to 6 million years ago (mya) Humanlike primates

appeared that were different from the other primates.

2. Hominids ate both meat and plants, walked upright on two legs.

a. Shared some of these characteristics with

gorillas, orangutans, and chimpanzees, but a larger brain

separated them from apes!!!!

I. Primates

F. African Origins

1. Early 1920’s a fossil skull was discovered in a quarry in South

Africa.

a. Skull had small space for brain but humanlike jaw and

teeth.

2. Fossil named Australopithecus, was one of the oldest

hominids discovered.

3. An almost complete skeleton of Australopithecus was found in

N. Africa in 1974, called Lucy.

a. Had similar brain, but was thought to have walked upright.

b. This fossil indicates that modern hominids might have

evolved from similar ancestors.

I. Primates

G. Early Humans

1. 1960’s the hominid fossil that was found in Africa was more like

present day humans than Australopithecus.

a. Hominid fossil was named Homo habilis , meaning “handy

man” because simple tools were found near him.

b. Homo habilis is estimated to be 1.5 to 2 million years old.

c. Homo habilis gave rise to the Homo erectus, about 1.6

million years ago.

i. Homo erectus had a large brain than Homo habilis, and

traveled from Africa to Southeast Asia, China, and

possibly Europe.

d. Homo habilis and Homo erectus are thought to be

ancestors of humans. **Because they had larger brains

and more human like features than Australopithecus**

II. Humans

A. Homo sapiens

1. Evolved about 400,000 years ago; according to fossil records.

2. Neanderthals and Cro-Magnon probably lived at the same time

in parts of Africa and Europe about 125,000 years ago.

II. Humans

B. Neanderthals

1. Characteristics of Neanderthals

a. Short, heavy bodies with thick bones, small chins, and

heavy browridges were physical characteristics of

Neanderthals.

b. Families lived in caves

c. Used well made stone tools to hunt large animals.

2. Disappeared from fossil record about 30,000 years ago.

3. Probably not direct ancestors of modern humans, but represent

a side of human evolution.

II. Humans

C. Cro-Magnon Humans

1. Fossils have been found in Europe, Asia, and Australia; date

from 10,000 to about 40,000 years in age.

2. Physical appearance was almost the same as that of modern

humans.

3. Characteristcs

a. Lived in caves, made stone carvings, buried their dead

4. The oldest recorded art has been found on the walls in caves in

France.

a. Painted bison, horses, and people carrying spears.

5. Cro-Magnons are thought to be direct ancestors of early

humans, Homo sapiens, which means wise humans.

6. Evidence indicates that modern humans, Homo sapien

sapiens, evolved from homo sapiens.