1. Evolution of Early Hominids Evolution of Later Hominids
CH 32 - Outline
Evolution of Primates
Mobile Limbs
Binocular Vision
Evolution of Early Hominids
Evolution of Later Hominids
Evolution of Early Homo
Modern Humans
Human Variation

2. The evolution of primates is characterized by trends towards:
Mobile limbs
Grasping hands
A flattened face
Binocular vision
A large, complex brain, and
A reduced reproductive rate

3. Primate Diversity

4. Prosimians Primate Diversity 4
Prosimians are a type of primate that include lemurs, lorises, bushbabies, and tarsiers, but not monkeys, apes, or humans (simians).
They are considered to have characteristics that are more "primitive" than those of monkeys and apes.
Prosimians are the only primates native to Madagascar, and are also found in Africa and Asia.
Primate Diversity 4

5. New World Monkeys
New World monkeys differ slightly from Old World monkeys in several aspects.
The most distinction is the nose, which is the feature used most commonly to distinguish between the two groups. The scientific name for the New World monkeys, Platyrrhini, means "flat nosed".
New World monkeys are the only monkeys with prehensile tails—in comparison with the shorter, non-grasping tails of the anthropoids of the Old World.

7. Old World Monkeys
Old world monkeys are more closely related to apes than new world monkeys

8. Old World Monkeys
The Old World monkeys are native to Africa and Asia today, inhabiting a range of environments from tropical rain forest to savanna, shrubland and mountainous terrain, and are also known from Europe in the fossil record.
Old World monkeys are medium to large in size, and range from arboreal forms, such as the colobus monkeys, to fully terrestrial forms, such as the baboons.

10. Apes: African, Asia, and Human?

11. Mobile Limbs Hands and feet
Most primates have flat nails
Sensitive pads on the undersides of fingers and toes
Many also have both an opposable big toe and thumb
Mobile limbs and clawless opposable digits allow primates to freely grasp and release tree limbs

12. Evolution of Primate Hand

13. Binocular Vision
Stereoscopic vision
Depth perception
Allows primates to make accurate judgments about distance and position of adjoining tree limbs

14. Binocular Vision

15. Primate Characteristics
Opposable thumb
Nails instead of claws
Single births
Binocular vision
Expanded, complex brain
Emphasis on learned behavior

16. Surviving anthropoids are classified into three superfamilies
Evolution of Primates
Prosimians were the first type of primate to diverge from the human line
Surviving anthropoids are classified into three superfamilies
New World monkeys
Old World monkeys
Hominoids

17. Evolution of primates

18. Evolution of Primates

19. Proconsul is believed ancestral to hominids
Evolution of Hominids
Proconsul is believed ancestral to hominids
Phylogenetic tree indicates humans are most closely related to African apes
Genetic changes used as a molecular clock to measure relatedness of different groups
Last common ancestor appears to have lived about 7 mya

20. Monkey Skeleton Compared to Proconsul Skeleton

21. Skeletal differences between humans and apes largely because:
Hominids
Hominid fossils:
Must have an anatomy suitable for standing erect and walking on two feet
Bipedalism
Skeletal differences between humans and apes largely because:
Humans are bipedal, while
Apes are quadrupedal

22. Adaptations for Standing 1. Location of spine in skull 2
Adaptations for Standing 1. Location of spine in skull 2. Human spine is S-shaped; ape spine is curved Human pelvis is bowl shaped; ape pelvis is long and more narrow Humans femur angle in towards the knees; ape femurs angle out. 5. Human knees can support more weight than ape knees Human foot has an arch; ape foot has no arch.

23. Australopithecines Australopithecines:
Evolved and diversified in Africa 4 mya
Possibly a direct ancestor of humans
Southern Africa
Australopithecus africanus
Eastern Africa
Australopithecus afarensis

24. Human Evolution

25. Australopithecus afarensis
The specimen was discovered in 1974 at Hadar in the Awash Valley of Ethiopia’s Afar Depression by Donald Johansson of the Cleveland Museum of Natural History
Lucy is estimated to have lived 3.2 million years ago.[
The discovery of this hominid was significant as the skeleton shows evidence of small skull capacity akin to that of apes and of bipedal upright walk akin to that of humans
Providing further evidence supporting the view that bipedalism preceded increase in brain size in human evolution

26. Australopithecus afarensis
Named “Lucy” after the Beatles song “Lucy in the Sky with Diamonds”
Several hundred pieces of bone representing about 40% of the skeleton

27. Evolution of Early Homo
Homo habilis
Dated between 2.3 and 1.4 mya
May be ancestral to modern humans
Skulls suggest portions of the brain associated with speech were enlarged
Ability to speak may have led to hunting cooperatively and the advent of culture

28. Homo erectus and similar fossils
Found in Africa, Asia, and Europe
Dated between 1.9 and 0.3 mya
Larger brain and flatter face than Homo habilis
Much taller than previous hominids
Thought to have first appeared in Africa and then migrated into Asia and Europe
First hominid to use fire

29. Homo ergaster

30. Evolution of Modern Humans
Most researchers believe Homo sapiens evolved from Homo erectus
Multiregional Continuity Hypothesis
Similar evolution occurred in many different places
Out-of-Africa Hypothesis
H. sapiens evolved from H. erectus only in Africa, and thereafter migrated to Europe

31. Evolution of Modern Humans
Which of these makes more sense and why?

32. Neanderthals
Neanderthal (H. neanderthalensis) skeletons were first discovered in Germany’s Neander Valley
Skeletons date back 200,000 years
Massive brow ridges with protruding nose, jaws, and teeth
Heavily muscled
Culturally advanced
Manufactured variety of tools

33. Neandertals

34. Oldest fossils to be designated H. sapiens
Cro-Magnons
Oldest fossils to be designated H. sapiens
Modern humans who entered Asia and Europe from Africa 100,000 years ago
Made advanced stone tools
Accomplished hunters
Hunted cooperatively
First to have language

35. Cro-Magnons

36. Comparative study of mitochondrial DNA
Human Variation
Hypothesized that human variations evolved as adaptations to local environmental conditions
Bergmann’s Rule - Animals in colder regions of their range have a bulkier body build
Allen’s Rule - Animals in colder regions of their range have shorter limbs, digits, and ears
Comparative study of mitochondrial DNA
Suggests human populations have a common ancestor no more than a million years ago

37. Ethnic Groups