1. Chapter 16
Primate Evolution

2. What is a Primate?
A group of mammals that include lemurs, monkeys, apes, & humans that evolved from a common ancestor

3. Characteristics of Primates
Movable fingers & toes
Flattened nails instead of claws
Opposable thumb
Used for grasping and manipulating tools
Color vision
Aids in depth perception
Front-facing eyes (perceive depth)
Rounded head with flattened face

4. More primate characteristics
Flexible shoulder and hip joints
Large Brain
Leads to diverse behaviors and social interactions
Binocular vision
Perceive depth and gauge distances

5. Common Ancestry
Humans are not descended from chimpanzees or modern apes, but they likely all descended from a primitive apelike ancestor.
Evidence: structural and social similarities

6. Bipedalism
One group of ancestors (hominoids) became bipedal (they walked on two feet).
Why?
Maybe they had to leave the trees in search of food on the ground.
These bipedal primates are called hominids—modern humans and their direct ancestors

7. Why was bipedalism beneficial?
Increased speed
Hands are free to feed and protect young
Able to use tools

8. How do we know what ancient hominids were like?
Paleoanthropologists study fossils of hominids to find out what they were like.
Shape and arrangement of bones gives clues about how they lived.

9. Who were the first hominids?
Australopithecines
Lived in Africa
Possessed both apelike & humanlike characteristics
“Lucy” was the first complete Australopithecine fossil found (3.2 million yrs)
Small, apelike brain

10. A new genus
Hominids with a large cranial (brain) capacity have been grouped into the genus Homo.
Examples:
Homo erectus
Homo sapiens
Evolved from Homo erectus

11. Sister species of Homo sapiens
Neanderthals
Larger brains than modern humans
Shorter, stalkier
Lived in caves
Used tools
Spoken language
Thick bones, large faces
Existed at the same time as Homo sapiens

12. Early Homo sapiens Cro-magnons
Same height, skull structure, tooth structure, & brain size as modern humans
Tool-makers, artists (cave drawings)
Language

13. Modern Humans Originated in Africa 100,000-200,000 years ago
Inhabited Africa, Asia, & Europe before crossing a land bridge into N. America