1. Fossil Evidence for Hominid Evolution
SC.912.L.15.11

2. 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

3. 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

4. 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?)

5. 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.

6. 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.

7. 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.

8. 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

9. Human evolution was a series of adaptive radiations
First Adaptive Radiation: 6-7 mya in the late Miocene, potential last common ancestors
Second Adaptive Radiation: 4-5 mya in early Pliocene, first true hominids
Third Adaptive Radiation: 3-4 mya in middle Pliocene, more hominids
Fourth Adaptive Radiation: 2-3 mya in late Pliocene, more & “robust” hominids
Fifth Adaptive Radiation: mya in late Pliocene & first ice age, genus Homo

10. First Adaptive Radiation
6-7 mya in the late Miocene, potential last common ancestors
1. Sahelanthropus tchadensis
6-7 mya in Chad (North Central Africa)
2. Orrorin tungenensis
6 mya in Kenya (East Africa)
Note: We know little about the lifeways of these species. However, we do know that they were forest adapted.

11. 1. Sahelanthropus tchadensis
Discovered in Chad (6-7 mya)
Most complete cranium from this time period
Mosaic of ape & human-like features, but at the “ape grade” of evolution:
Cranial capacity ( cc)
U-shaped upper jaw
Very wide distance between the orbits
Large, thick continuous brow ridge
Human-like flat face
Human-like dentition

12. 2. Orrorin tungenensis
Fossils from Tugen Hills in Kenya have been dated to about 6 mya
Earliest Evidence for
Walking on Two Legs?
How far back in time does the record of bipedalism extend?

13. Orrorin tungenensis (cont.)
Fossils Include: upper portion of a femur, lower portion of the humerus, some lower jaw fragments, & teeth
Arm bone: virtually identical to that of a chimpanzee
Femur: more human-like, most important for showing adaptations for walking on 2 legs
Was Orrorin a direct human ancestor, or a common ancestor of chimps and humans?

14. Second Adaptive Radiation
4-5 mya in early Pliocene, first true hominids
1. Ardipithecus ramidus
mya in Ethiopia (East Africa)
2. Australopithecus anamensis
mya in Kenya (East Africa)
Note: We know little about the lifeways of these species. However, we do know that they were forest adapted and fully bipedal.

15. 1. Ardipithecus ramidus Earliest True Hominid or Last Common Ancestor?
LAST COMMON ANCESTOR OF CHIMPS & HUMANS MOST LIKELY HAD A MIX OF FEATURES: SOME RETAINED IN CHIMPS, OTHERS RETAINED IN HUMANS!

16. Ardipithecus ramidus (cont.)
Between 4.5 and 5.5 mya from the Middle Awash valley site in Ethiopia
Fossil Remains very fragmentary: limb bones, toe bones, jaws & teeth
Straight toe bones suggest it may have been bipedal
A mosaic of features seen in later hominids & modern chimpanzees

17. 2. Australopithecus anamensis
Lake Turkana Region of Kenya
mya
Probably walked upright
Teeth enamel thicker than Ardipithecus ramidus, so diet included hard foods

18. Australopithecus anamensis (cont.)
Fossil Remains very fragmentary
Those shown here include:
Jawbone
part of the front of the face
parts of an arm bone (radius)
fragments of a lower leg bone (tibia)

20. Third Adaptive Radiation
3-4 mya in middle Pliocene, many hominids
1. Australopithecus afarensis (“Lucy”)
3-4 mya in East Africa
2. Australopithecus africanus
2.5-4 mya in South Africa
3. Kenyanthropus platyops
mya in Kenya
Note: We know little about the lifeways of these species. However, we do know that they lived in open woodlands & along wooded streams in the savannas, ate fruits and soft foods, maybe had a tool-culture like modern chimps

21. 1. Australopithecus afarensis
3-4 mya in East Africa
Pelvis & leg bones resemble modern humans
Sexual dimorphism (males larger with sagittal crest)
Tree climbers (curved fingers & toes)
Ape-like Features:
Small brain case (430 cc.)
Prognathic (jutting out) face
U-shaped palate (v. parabolic shape)

22. Australopithecus afarensis

23. A. afarensis Skeleton - Lucy

24. 2. Australopithecus africanus
4-2.5 mya in Transvaal region of South Africa
1924: 1st Australopithicine to be described by Raymond Dart!
Globular cranium, slightly higher ratio of brain to body size than A. afarensis
Face less prognathic than A. afarensis
Proportions of arm to leg lengths may be more ape- like than A. afarensis

25. Australopithecus africanus

26. Australopithecus africanus
best known A. africanus cranium (front & lateral views)
Australopithecus africanus
Most complete A. africanus skull
Taung Child

27. A. afarensis A. afarensis verses A. africanus
Australopithecus afarensis
Australopithecus africanus

28. 3. Kenyanthropus platyops
mya: found in 2001 west of Lake Turkana in Kenya
Ape-like features: small ear canal, small brain case
Human-like features: flat face, small molars
Importance: flat face appeared early in evolution, alongside the range of other facial forms.
Evidence that evolution is not linear or progressive

29. Kenyanthropus platyops

30. Fourth Adaptive Radiation
1-3 mya in late Pliocene, more & “robust” hominids
1. Paranthropus boisei
mya in East Africa
2. Paranthropus robustus
2-1 mya in South Africa
3. Australopithecus garhi
2-3 mya in East Africa
Note: We know little about the lifeways of these species. However, we do know that they lived in open dry woodlands & savannas. The robust species are famous for eating hard to chew food, like seeds, nuts, and roots. May have used tools to dig for roots in dry seasons.

31. 1. Paranthropus boisei
mya in East Africa: Ethiopia, Kenya, Tanzania
Largest teeth found in any hominid!
Referred to as “hyper-robust” due to massive molars and premolars
Skull: broad, short face with flaring cheek bones, relatively small brain, pronounced sagittal crest in males
Skull and dental features are adaptations for heavy chewing!

32. Paranthropus boisei (KNM-ER 406)

33. Paranthropus boisei (KNM-ER 406)

34. Paranthropus boisei (KNM-ER 406)

35. Paranthropus boisei (OH 5)

36. 2. Paranthropus robustus
2-1 mya in South Africa
Short, broad face with deep zygomatic arches (cheek bones). Larger individuals have sagittal crests.
Large molars covered with thick enamel
Wear patterns on teeth: herbivorous diet of hard resistant foods such as seeds, nuts, roots
Lived in grasslands near rivers and wetlands

37. Paranthropus robustus

38. 3. Australopithecus garhi
2-3 mya in East Africa: spotty fossil record, cranial & dental remains found in 1999 in Bouri, Ethiopia
Bones of antelopes, horses, and other animals with cut marks made by stone tools: butchering animals & smashing bones for marrow. First meat eaters?
Molars too large to be early Homo
Ape-like long lower arm, human-like upper arm & leg
Mixed traits: classified as a new species, maybe ancestor of early Homo

39. Australopithecus garhi

40. Australopithecus garhi
One surprise in the A. garhi skull was enormous back teeth, instead of smaller ones seen in later Homo species (Video Image/UC Berkeley)

41. Australopithecus garhi
EARLIEST BUTCHERS:
Signs that hominids scraped & smashed animal bones, like this antelope tibia, 2.5 mya
Earliest documented percussion marks made by hominids, presumably extracting fatty marrow from these bones