Human evolution began with early hominids like Proconsul that lived 20 million years ago. Early humans included Australopithecines like Lucy that walked upright 3.9-3 million years ago. Genus Homo emerged around 2.5 million years ago including Homo habilis and Homo erectus. Neanderthals lived in Europe 200,000-24,000 years ago before being replaced by modern humans with globular brains and flatter faces 130,000-90,000 years ago.

1. HUMAN EVOLUTION
A.Hominids
- Evolved during the Miocene Epoch
1. Proconsul- among the oldest known hominoids
- had features that suggest a close link to the
common ancestors of apes & humans
*Proconsul heseloni – species that lived in the trees of
dense forests in eastern Africa (20million years ago)
- an agile climber; w/ flexible backbone & wide range
of movement

4. 2. Afropithecus
- evolved about 18 million years ago in
Arabia & Africa after the large apes
underwent several radiations
3. Kenyapithecus – from Africa
4. Griphopithecus – from western Asia
5. Dryopithecus – from europe
* Appropriate classification of Hominoids = ?

5. Humans as Apes
•About 98% of the genes in people &
chimpanzee – are identical
Modern humans – have a number of physical
characteristics reflective of an ape ancestry
a. Shoulders with a wide range of movement
b. Fingers capable of strong grasping
Both – have larger brains & greater cognitive
ability than do most other mammals

6. Differences of modern humans from apes:
1.Much larger and more complex brains
2.Unique intellectual capacity
3.Elaborate forms of culture and
communication
4.Habitually walk upright
5.Can manipulate very small objects
6.With a throat structure that makes speech
possible

7. The first Humans: Australopithecines
-First evolved around 5 million years ago in
Africa; an ape-like species
2 important traits that distinguished it from apes:
a. Small canine teeth
b. Bipedalism
• Ardipithecus – the earliest Australopith species
known today
* Australopithecus and Paranthropus – other
species

11. Transition from Ape to Human:
Adaptations that marked the transition from
ape to human:
-Australopiths – resembled the apes in terms
of the face and amount of hair in the
body; brain size (therefore probably
with ape-like mental abilities; social
life similar to chimpanzees

12. Australopith Characteristics:
•Bipedal stance; habitual upright walking
1.Low cranium behind a projecting face
2.Brain size of 390 to 550 cubic cm (in the range
of an ape’s brain)
3.Body weight range: 27 to 49 kg
4.1.1 to 1.5 m tall
5.Large degree of sexual dimorphism, males much
larger than females
6.Had curved fingers & long thumbs with a wide
range of movement

13. 4 species of early australopiths:
- One from Genus Ardipithecus; 3 from
Genus Australopithecus
(1)Ardipithecus ramidus
-fossils – had a very ancient combination of
apelike and humanlike traits
-teeth – had a thin outer layer of enamel
-skeleton shows strong similarities to chimpanzee
but with slightly reduced canine teeth
-adaptations for bipedalism

14. (2) Australopithecus anamensis
1965 – discovery by a research team of Harvard
Univ. of a single arm bone of an early human
at Kanapol, Northern Kenya
1994- discovery by Meave Leakey of numerous teeth
& bone fragments at same site
- fossils discovered – about 4.2-3.9 million years old
- skull appeared ape-like; enlarged tibia – indicated
bipedal walking (supports full body weight)

15. (3)Australopithecus afarensis
- a gracile australopith that thrived in eastern
Africa (about 3.9-3 million years ago)
*Lucy – the most celebrated fossil of this species
- discovered by Donald Johanson in 1974 at
hadar, Ethiopia
- also discovered in Laetoli, northern Tanzania (1978)
by Mary Leakey; best known for its spectacular
trails of bipedal human footprints

16. -Foot anatomy & gait did not exactly match those
of modern humans – indication that they not only
lived on the ground but also on trees
-Skeleton of Lucy – indicates that it had longer, more
powerful arms than most later human species
(adept to climbing trees)
-Height of Lucy – only 1.1m (3.5 ft) tall; other similar
fossils – about 1.5 m tall
Possibilities:
- 2 species; one highly dimorphic species;
large adults (males), small adults (females)

18. (4)Australopithecus africanus
- thrived in the Transvaal region (now South Africa)
between about 3.5 – 2.5 million years ago
- discovered by Raymond Dart (1924) in Taung,
South Africa
- specimen as of a young child – Taung Child
- late 1930s – Robert Broom – unearthed many
more of these skulls from the Transvaal site

19. Globular braincase and less primitive-looking
face and teeth than A. afarensis
- features of A. africanus which scientists
considered to be a likely ancestor of the genus,
Homo
Heavily built facial and cranial features – were
thought to be signs of being ancestors of the
robust australopiths that lived later in same region
1998 – Ronald Clarke – unearthed an almost complete
early australopith skeleton in Sterkfontein

20. Late Australopith
-Evolved around 2.7 million years ago
-Had megadont cheek teeth – wide molars and
premolars coated with thick enamel
-With small incisors
-Robusts had expanded, flattened and more vertical
face than the gracile australopiths
-had a sagittal crest on top of head to which thick jaw
muscles were attached
-zygomatic arches curved out wide from side of face
and cranium –for massive chewing muscles to
pass through

21. •Research revelations:
- Robust australopiths actually stood about same
height and weight as A. afarensis & A. africanus
(1)A. aethiopicus
- the earliest known robust species
- lived in eastern Aftica about 2.7 million years ago
*”Black skull” – a 2.5 million year old skull fossil
discovered in 1985 at West Turkana, Kenya
by Alan Walker
- helped define this species
- with similar primitive features as A. afarensis

22. (2)A. boisei
- the other ell-known East African robust
australopith
- lived between about 2.3 and 1.2 million years ago
1959 – Mary Leakey – discovered the original fossil
of this species – a nearly complete skull at
the site of Olduvai Gorge, Tanzania
Louis Leakey – originally named the new species as
Zinjanthropus boisei (East African Man)

23. Features:
1.Skull – dates back from 1.8 million years ago
2.Has a massive, wide and dished-in face capable
of withstanding extreme chewing forces
3.Molars four times the size of those in modern humans
(3)A. robustus
- southern robust species which lived between about
1.8 and 1.3 million years ago in Transvaal
1938 – Robert Broom – found a fossil jaw and molar
that looked different from those of A. africanus

24. - named a new species, Paranthropus robustus
-Late 1940s & 1950 – discovery by Broom of many
more fossils of this species at the Transvaal site of
Swartkrans
Fate of the Late Australopith:
- Last robust australopiths – died out about
1.2 million years ago
*Factors which may have contributed to their decline:
a. Fluctuation in climate patterns around the world
- reduced the food supply on which robusts
depended

25. b.Interaction with larger-brained members of the
genus, Homo
c. Competition with several other species of plant-
eating monkeys and pigs

26. The Genus Homo
-Have evolved at least 2.3 million to 2.5 million
years ago
*Larger brains – made them distinctly different
from their predecessors
Three periods in the evolution of Homo:
a.Early Homo – resembled gracile australopiths;
- lived until possible 1.6 & 1.8 million years ago
b.Middle Homo – began perhaps between 2 million
and 1.8 million years ago
- Species evolved an anatomy similar to modern
humans but with smaller brains

27. c. Late Homo – around 200,000 years ago
- species have evolved large and complex brains
and eventually language
- evolution of culture
A. Early Homo
2 species:
a. Homo habilis
*early 1960s – Louis Leakey, John Napier &
Philip Tobias
- discovered in Olduvai Gorge, Tanzania , a group of
early human fossils that showed a cranial capacity
above the range of that in known australopiths

28. Features:
1.Evolved between 1.6 million and 2.4 million yrs ago
2.Lived in eastern and possibly South Africa
3.Has a cranial capacity from 590 to 690 cu cm.
4.With smaller and narrower molar teeth, premolar
teeth and jaws
5.Exhibited sexual dimorphism
6.Ratio of length of arms to legs greater than that in
the australopith Lucy
7.With very ape-like body proportions
8.Had more modern-looking feet and hands capable of
producing tools

29. b.Homo rudolfensis
Features:
1.Named after Lake Rudolf
2.Date from about 1.9 million years ago
3.Had a larger face and body than did H. habilis
4.Cranial capacity – about 750 cu cm
5.Had fairly large teeth
6.Thigh bones found by scientists – suggest a body
size of 1.5 m (5 ft) and 52 kg (114 lbs)

30. Middle Homo
1.Homo ergaster
- evolved in Africa around 2 million years ago
- had a rounded cranium with a brain size of
800 to 850 cu cm
- with a prominent brow ridge
- small teeth, and many features it shared with the
later H. erectus
*Turkana Boy: the most important fossil of this species
- had elongated leg bones and arm
- leg and trunk proportions – match those of modern
humans
- quite tall and slender

31. Indications in terms of the anatomy of the Turkan Boy:
a.Well adapted in terms of walking and for running
long distances in a hot environment
b.No significant amount of tree climbing
(2)Homo erectus
- Humans – first evolved in Africa
- Southeast Asia - w here the earliest human species
known to have spread in large numbers were first
discovered.
*Eugene Dubois – found the cranium of an early human
on the Indonesian Island of Java (called
Pithecanthropus erectus) - “erect ape-man,
but today called Homo erectus

32. Features:
1.Appears to have evolved in Africa between
1.8 million and 1.5 million years ago
2.With a low and rounded braincase that was elongated
from front to back
3.Prominent brow ridge
4.With an adult cranial capacity of 800 to 1,250 cu cm
(twice that of australopiths)
5, Thicker bones than those of earlier species
6.Prominent muscle markings and thick, reinforced
areas on the bones – indicative of a body that could
withstand powerful movements & stresses

33. 7. With much smaller teeth than australopiths
8. With heavy and strong jaw
1920s and 1930s – Franz Weidenreich
- excavated the most famous collections of
H. erectus fossils from a cave at the site of
Zhoukoudian, China
- called these Sinanthropus pekinensis or
Peking Man; later reclassified as H. erectus

34. (3)Homo heidelbergensis
- many paleoanthropologists – believed that early
humans migrated into Europe by 800,000 years ago
and that these were not H. erectus
- considered to be early migrants into Europe who
predated both Neanderthals and H. sapiens in the
region
- name comes from a 500,000 year old jaw found near
Heidelberg, Germany

35. -Considered to be massive-boned and larger-brained
humans replacing populations of H. ergaster
-Fossils of these found at sites in Bodo, Ethiopia;
Saldanha, South Africa; Ndutu, Tanzania and
Kabwe, Zimbabwe
-Were thought to have given rise to both Neanderthals
(in Europe) and H. sapiens (in Africa)

36. Late Homo
Neandertals and other Archaic Humans
-Lived in areas ranging from Western Europe through
Central Asia from about 200,000 to between 36,000
and 24,000 years ago
-Name comes from fossils found in 1856 in the
Feldhofer Cave in the Neander Valley in Germany
•Engis, Belgium (1829) & Forbes Quarry, Gibraltar
(1848) – where there were prior discoveries also
representing Neandertals

39. Features:
1.Walked fully upright without a slouch or
bent knees
2.Cranial capacity quite large (about 1500 cu cm),
slightly larger than that of modern humans
Differences from Modern Humans:
1.Skull with a low forehead
2.Large nasal area (suggesting a large nose)
3.Forward-projecting nasal and cheek region
4.Prominent brow ridge with a bony arch over
each eye
5.A non-projecting chin
6.An obvious space behind the third molar

40. 7. With a more heavily built and large-boned
skeleton
8. Bowing of the limb bones in some
9. Broad scapulae (shoulder blades)
10 .hip joints turned outward
11. With a long and thin pubic bone
12. With a short lower leg and arm bones relative
to the upper bones
13. With large surfaces on the joints of the toes
and limb bones
•These traits made a powerful, compact body of
short stature (males = 1.7 m & 84 kg; females =
1.5 m and 80 kg.)

41. Archaic Species – fossils, which, according to
scientists, are distinct from but similar to those
of Neanderthals
Modern Homo sapiens:
1.Oldest known fossils that possess skeletal physical
features typical of modern humans – date from
between 130,000 and 90,000 years ago
2.Have smaller bro ridge, if any
3.Globe-shaped braincase
4.Flat or only slightly projecting face of reduced size,
located under the front of the braincase

42. * Only humans among all mammals have a face
positioned directly beneath the frontal
lobe of the brain
5.Cranial capacity ranges from about 1,000 to
2,000 cu cm, with the average being about
1,350 cu cm.