1. Chapter 2 – Human Evolution

2. Today’s Objectives How do humans differ from apes?
Skeleton, organs, culture
Why was Homo erectus so successful as an early hominid?
What happened to Neandertals?
Be able to briefly trace the cultural development of:
tools, fire, clothing, shelter, art
What is so important about the Upper Palaeolithic?

3. Theories of Evolution Origin Myths/Cosmologies Greek – Prometheus
Genesis
Western examples
Left: Prometheus and Athena
Top: God and Adam

4. Carl Sagan’s Universe Calendar
24 days = 1 billion years
1 second = 475 years
“Big Bang” January 1
Milky Way May 1
Solar System September 9
Life on Earth September 25
Humanlike Primates December 31, 10:30pm
Milky Way

5. Theories of Evolution Darwin and Wallace, 1850s
Evolution theory holds that existing species of plants and animals have emerged over millions of years from simple organisms.
Darwin, On the origin of species, 1859
Influenced by the principle of uniformitarianism
Charles Darwin

6. Theories of Evolution - Corollaries
Darwin’s principle of natural selection
“Natural selection is the gradual process by which nature selects the forms most fit to survive and reproduce in a given environment.”
For natural selection to work on a given population, there must be variety within that population and competition for strategic resources.
The concept of natural selection argues that organisms which have a better fit within their environmental niche will reproduce more frequently than those organisms that fit less well.

7. Theories of Evolution - Corollaries
Random genetic drift is the loss of alleles from a population's gene pool through chance.
Mutation introduces genetic variation into a breeding population.
Gene flow occurs through interbreeding: the transmission of genetic material from one population to another. Gene flow decreases differences and inhibits speciation, the formation of new species.

8. Theories of Evolution - Corollaries
Mendel’s principle of inheritance, 1856
The science of genetics explains the origin of the variety upon which natural selection operates.
By experimenting with successive generations of pea plants, Mendel came to the conclusion that heredity is determined by discrete particles, the effects of which may disappear in one generation, and reappear in the next.

9. Other Theories
Creationism accounts for biological diversity by referring to the divine act of Creation as described in Genesis.
Catastrophism is a modified version of Creationism, which accounts for the fossil record by positing divinely authored worldwide disasters that wiped out the creatures represented in the fossil record, who were then supplanted by newer, created species.
Intelligent Design states that modern physics and cosmology have uncovered evidence for intelligence in the structure of the universe and this intelligence seems to act with us in mind and that the universe as a whole shows evidence of design.

10. Early Primates Prosimians (65mya) Monkeys (35mya) Apes (23mya)
Hominids (5mya)

11. Early Primates - Traits
Common physical primate traits:
Dense hair or fur covering
Warm-blooded
Live young
Suckle
Infant dependence
Common social primate traits:
Social life
Play
Observation and imitation
Pecking order
Common Primate Traits

12. Primate Family Tree
Orangutan
Crown lemur

13. Evolution of Bipedalism
Anatomical changes
Neck (1), chest (2), lower back (3), hips and pelvis (4), thighs (5), knees (6), feet (7)
Theories
Tool use and bipedalism (Darwin/Washburn)
Energy efficiency and bipedalism (Isbell/Young)
Radiator theory (Falk)
Body temperature and bipedalism (Wheeler)
Habitat variability and bipedalism (Potts)
Reproduction and bipedalism (Lovejoy)
Canine reduction and bipedalism (Jolly)
(Click for interactive skeleton)

14. Pre-hominid Evolution
Ardipithecus ramidus ? mya
A. anamensis
A. afarensis
A. bahrelghazali
A. africanus
P. aethiopicus
A. garhi ?
P. boisei
P. robustus
Bipedalism
Tools
Language
Reconstruction of Australopithecine

15. Hominid Evolution Homo habilis (2.0 – 1.6mya)
H. rudolfensis ( mya)
H. erectus (1.9-27kyBP)
H. heidelbergensis ( kyBP)
H. neanderthalensis (300-30kyBP)
H. sapiens (130kyBP – present)
Scale: Millions of Years BP

16. Hominid Evolution Major Homo advances: Brain size Better bipedalism
Hunting
Fire (H. erectus)
Tools
Oldowon (H. habilis)
Acheulean (H. erectus)
Mousterian (H. heidelbergensis)
Solutrean (H. sapiens)
Built shelters (H. heidelbergensis)
Clothing (H. neandertalensis)
Language (Neandertals?)

17. Homo habilis 612 cc brain 2.3 - 1.6 mya first toolmaker
prognathic face, brow ridge
probable meat-eater
possibly arboreal
discovered in 1960 by Leakeys
no speech
Artist’s representation of a Homo habilis band as it might have existed two million years ago.

18. H. habilis v. H. erectus
Finds in east Africa indicate that Homo habilis was not very different from the australopithecines in terms of body size and shape.
The earliest Homo erectus remains indicate rapid biological change.
The fossil record for the transition from H. habilis to H. erectus supports the punctuated equilibrium model of evolution.
H. erectus was considerably taller and had a larger brain than H. habilis.

19. Homo erectus 1891 - Eugene Dubois discovers H. erectus in Java
Dubois calls it Pithecanthropus erectus initially, also dubbed “Java Man”
finds in China called Sinanthropus
dates from 1.9 mya to 27,000 years B.P.
994 cc brain size (compare to 612 for H. habilis)
Acheulean tool industry
Photograph of Nariokotome boy, an early Homo erectus found near Lake Turkana, Kenya.

20. Homo erectus – 1.9mya to 27k yBP
Why was H. erectus so successful?
Less sexual dimorphism = possible pair bonds, marriage
Less hair on body = wearing of furs, other clothing
Wearing of furs = ability to live further north
Quick adaptation to environment without physical changes
Culture is main reason H. erectus was so successful
organization for hunting
ability to protect against predators
control of fire?
possible campsites
tools (Acheulean industry)
Distribution of H. erectus

21. Homo neanderthalensis
discovered in the Neander Valley (Tal) near Dusseldorf, 1856
massive brain--about 1,400cc on average
large torso, short limbs, broad nasal passages
later remains show decrease in robustness of the front teeth and face, suggesting use of tools replaced teeth
retained occipital torus, some mid-facial prognathism
The skull of the classic Neandertal found in 1908 at La Chapelle-aux-Saints.

22. Neandertal Culture
Homesites – In caves, also in the open (near rivers, framed with wood and covered with skins)
Burial – Is there evidence of purposeful burial and ritual?
Language – Could Neandertals talk or not?
Tools – Mousterian tradition
Top: Reconstruction of Neandertal burial from Shanidar cave
Bottom: Mousterian tools

23. What happened to Neandertals?
H. neanderthalensis coexisted with H. sapiens for at least 20,000 years, perhaps as long as 60,000 years
What happened?
Neandertals interbred with H. sapiens
Neandertals were killed off by H. sapiens
H. sapiens drove Neandertals into extinction by competition

24. Homo sapiens Archaic – 100,000 to 35,000 years BP
Sometimes called Homo sapiens and Homo sapiens neanderthalensis
Modern – 35,000 years BP to present
Anatomically modern
Sometimes called Homo sapiens sapiens

25. Cro-Magnon Man Cro-Magnon humans
35,000 years B.P. in western Europe to 17,000 years B.P.
1,600 cc cranial capacity
Name comes from a hotel in France
Not a different species, just old Homo sapiens from Europe
Artist’s reconstruction of a Cro-Magnon man

26. Archaic H. sapiens Culture
Art
Traces of art found in beads, carvings, and paintings
Cave paintings in Spain and southern France showed a marked degree of skill
Female figurines
27,000 to 22,000 years B.P.
Called “venuses,” these figurines depicted women with large breasts and broad hips
Perhaps it was an example of an ideal type, or perhaps an expression of a desire for fertility

27. Archaic H. sapiens Culture
Cave paintings from 20,000 years ago at Vallon-Pont-d’Arc in southern France (left) and from Lascaux, in southwest France
Cave paintings
Mostly animals on bare walls
Subjects were animals favored for their meat and skins
Human figures were rarely drawn due to taboos and fears that it would somehow harm others

28. Upper Palaeolithic – Hotbed of Culture
40 – 10k yBP
Shelters
15,000 yBP Ukraine
Some made with mammoth bones
Wood, leather working; carpentry
Tools
From cores to blades
Specialization
Composite tools
Bow and arrow
Domestication of dogs
Gathering rather than hunting became the mainstay of human economies.
Top: Straw Hut
Left: Mammoth bone hut
Bottom: Tool progression

29. Modern Homo Sapiens Regional-Continuity Model (Milford Wolpoff, UMich)
Humans evolved more or less simultaneously across the entire Old World from several ancestral populations.
Rapid-Replacement Model (Chris Stringer, NHM London)
Humans evolved only once--in Africa from H. heidelbergensis ancestors--and then migrated throughout the Old World,
replacing their archaic predecessors. Also called the “Out of Africa” and “Killer Ape” hypothesis.

30. Social Organization Hunter-gatherer analogy Migration
Small group, low population density, nomadism, kinship groups
Migration
North America was the last colonized by hominids.
Beringia (land bridge) between Russia and Alaska
Asian origin of Native Americans
30,000 to 12,000 years B.P. was first migration

31. Human Variation
Modern humans vary in skin color, hair color, and eye color.
Will talk about anthropological conceptions of race and ethnicity later in the semester (April 23).