1. Chapter 6-3
Rate of Change

2. How Do New Species Form?
A new species can form when a group of individuals remains isolated from the rest of its species long enough to evolve different traits that prevent reproduction.
Example-Fig 1 on p181 The squirrels are separated by the Grand Canyon. They are the species but overtime can become separate species.

3. What Patterns Describe the Rate of Evolution?
Two patterns describe the pace of evolution: gradualism & punctuated equilibrium.

4. Gradualism
Involves small changes that add up to major changes over a long period of time.

5. Punctuated Equilibrium
Short periods of rapid change and then don’t change much.

7. Primates
A group of mammals that includes humans, apes, monkeys, and prosimians
Characteristics:
Opposable thumb (bends opposite index finger)
Binocular vision (eyes at front of head, 3-D)

9. Our closest living relative?
Chimpanzee!
97% of our genetic material is identical
Humans did not descend from chimps
Instead, humans and chimps share a common ancestor
Split approximately 7 mya

11. Hominids Hominids include humans and human-like ancestors
Walk upright on two legs for locomotion
Called bipedalism

12. Prosimians First primates Only 1 species, the lemur survives today
About 55 mya
Only 1 species, the lemur survives today

13. Australopithecines “Southern Man Ape”
Long arms, short legs, small brains
Brains are larger than ape brains, but smaller than modern humans
Lucy (1979) 2 mya
Footprints 3.6 mya
Australopithicus afarensis

15. Homo habilis “Handy Man” 2.3 mya Used crude stone tools
Short in size, small brain, and large jaw

16. Homo habilis

17. Homo erectus Survived for nearly 1 million years
Longer than any other species
Lived in caves, built fires, wore clothing, hunted large animals, made tools
Migrated across the globe

19. Homo sapiens? Neanderthals
230,000 years ago
Hunted large animals, made fires, wore clothing
Cared for the sick and elderly, buried the dead
Heavy brow rides, larger brain than modern humans

21. Homo sapiens Cro-Magnon
100,000 years old
Smaller and flatter faces, high round skulls, thicker and heavier bones
Made cave paintings, sculptures, and carvings
Complex social organization and civilizations

23. Cave Paintings