1. Human Evolution

2. Classification Hierarchy
Kingdom Animal
Phylum Chordate
Class Mammal
Order Primates
Family Hominids
Genus Homo
Species Sapiens

3. Human Evolution

4. Important Vocabulary Paleoanthropologist
Scientist who studies fossil evidence of human evolution.
Homininds
Group that includes humans and their immediate ancestors.

5. Background
It is very rare to find a complete skeleton of a fossilized hominid.
Scientists need to look at many different things to try and piece together the puzzle of human evolution.

6. Background Cont’d
When hominid fossils are found, several important characteristics can help determine origin and lifestyle of the species.
Did organism walk upright?
Curvature of spine, position where spine attaches to skull and shape of pelvis
Brain size?
Examine skull fragments
Diet?
Wear and tear on fossilized teeth
How and where did it live?
Fossils found in same area & environment found

7. Primates 2 Divisions of Primates Characteristics:
1. Anthropoid primates
2. Prosimean primates
Characteristics:
Flat Nails (no claws)
Prehensile hands and feet (grasping)
Color vision and depth perception

8. Anthropoid Primates Include: Brain size Opposable thumbs
marmosets
Monkeys
Apes
Humans
Brain size
Large relative to their body size
Opposable thumbs
Similar dental formula
number and arrangement of teeth

9. HUMANS Bipedalism – Ability to walk on 2 feet
Aligned toes = Bipedalism
Enlarged brain =Vertical face
Areas for speech in the brain
S- shaped spine
Bowl-shaped pelvis

10. Prosimean primates
Include:
Lemurs
Lorises
Tarsiers

11. Tarsier Skeleton

12. Gorilla Skeleton

13. Human Skeleton

14. Hominids Hominids include humans and extinct humanlike primates
The oldest known hominid fossils are between 6 and 7 million years old
First fossils found in Africa

15. Australopithecus NOT ancestral to modern humans!
Oldest known genus of hominids
Lived more than 4 million years ago
Knee joints- Allow bipedalism!
Australopithecus anamensis
Australopithecus afarensis – believed to have given rise to:
A. africanus
A. robustus
A. boisei
more than 1 million years ago
NOT ancestral to modern humans!

16. A. africanus !

17. A. boiser !

18. Discovery of Lucy!
Fossils of nearly half complete early hominid Australopithecus afarensis
suggests hominids became bipedal before their brains began to dramatically enlarge

19. Ardipithecus ramidus Recent discovery Not clear whether it was bipedal
4.4 million years old

20. Existence of hominid species not ancestral to modern humans implies…
Hominid phylogenetic tree is very branchy in appearance
Representing species died out, leaving no descendants.

21. Early Members of the genus Homo H. habilis & H. erectus
Ancestors to modern humans
Larger brains than australopithecines
May have had speech
Started to develop tools
Homo erectus
Homo habilis

22. FIGURE 17-15 Representative hominid tools
(a) Homo habilis produced only fairly crude chopping tools called hand axes, usually unchipped on one end to hold in the hand. (b) Homo ergaster manufactured much finer tools. The tools were typically sharp all the way around the stone; at least some of these blades were probably tied to spears rather than held in the hand. (c) Neanderthal tools were works of art, with extremely sharp edges made by flaking off tiny bits of stone. In comparing these weapons, note the progressive increase in the number of flakes taken off the blades and the corresponding decrease in flake size. Smaller, more numerous flakes produce a sharper blade and suggest more insight into toolmaking, more patience, finer control of hand movements, or perhaps all three.

23. Neanderthals
For years, the thinking among anthropologists was that homo sapiens, being superior to Neanderthal man, ran him off the planet. More recently, that view has been discarded and the picture become more complicated. For one thing, Neanderthals may have mixed with the ancestor of modern man, which means that we could be carrying Neanderthal genes.

24. Cro-Magnons
Cro-Magnons coexisted with Neanderthals in Europe and the Middle East for as many as 50,000 years
Cro-Magnons had domed heads, smooth brows, and prominent chins
30,000-year-old Cro-Magnon artifacts include:
Bone flutes
Ivory sculptures
Evidence of elaborate burial ceremonies

25. Cro-Magnon Cave Painting

26. Homo sapiens Evolved about 800,000 years ago A) Neanderthals
Were early Homo sapiens
They may be ancestral to modern humans OR
They may have died out and been replaced by modern humans

27. Some hypotheses:
1. some anthropologist think H. sapiens evolved in PARALLEL from populations of H. erectus all over the world. (interbreeding)
2. some anthropologists propose that H. sapiens DESCENDED from H. erectus in Africa and then dispersed across Earth.

29. Waves of Hominid Emigration
Two hypotheses have been proposed for the evolution of Homo sapiens
“African replacement” hypothesis
Also called Out of Africa, Recent-African-Origin
“Multiregional origin” hypothesis

30. “African Replacement” Hypothesis
Members of the genus Homo made repeated long-distance migrations out of Africa beginning 1.8 million years ago
H. sapiens emerged from Africa about 150,000 years ago and spread across the Near East, Europe, and Asia
The dispersing H. sapiens populations replaced all other hominids

31. FIGURE 17-18a Competing hypotheses for the evolution of Homo sapiens
(a) The "African replacement" hypothesis suggests that H. sapiens evolved in Africa, then migrated throughout the Near East, Europe, and Asia, displacing the other hominid species that were present in those regions.

32. “Multiregional Origin” Hypothesis
H. erectus emerged from Africa 1.8 million years ago and spread across the Near East, Europe, and Asia
Continued migrations and interbreeding occurred among widespread H. erectus populations
Regional populations of H. erectus evolved into H. sapiens

33. FIGURE 17-18b Competing hypotheses for the evolution of Homo sapiens
(b) The "multiregional" hypothesis suggests that populations of H. sapiens evolved in many regions simultaneously from the already widespread populations of H. erectus.