1. Human Evolution

2. Human Evolution
Describe the major anatomical features that define humans as primates
Primata = an order of mammals, including apes, monkeys, tarsiers and lemurs

3. Humans and Primates
Humans share the following characteristics with other Primates:
grasping limbs, with long fingers and a separated opposable thumb;
mobile arms, with shoulder joints allowing movement in three planes and the bones of the shoulder girdle allowing weight to be transferred via the arms;
stereoscopic vision, with forward facing eyes on a flattened face, giving overlapping fields of view;
skull modified for upright posture;
**Primates share a common ancestry

4. thumbs, upright, forward facing, shoulders

5. Hominids originated in Africa and spread to other continents
2. Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus, including A. afarensis and A. africanus, and Homo, including H. habilis, H. erectus, H. neanderthalensis and H. sapiens.
Hominids originated in Africa and spread to other continents
Ardipithecus fossils found in Ethiopia
Australopithecus and Homo habilis fossils found in Southern and Eastern Africa
Homo erectus fossils found in Eastern Africa and in Asia
Homo neanderthalensis fossils found in Europe
Homo sapiens fossils found in all continents except Antarctica

7. Ardipithecus ramidus Oldest hominid (4.4 million years ago)
more primitive (ape-like)
Bipedialism?
Low forehead
Small cranium
Protruding brow and jaw
Big teeth

8. Australopithecus afarensis
3.9 million years
“Lucy” (Fossil found 1978)
a low forehead 
bony ridge over the eyes
a flat nose and no chin 
more humanlike teeth, 
(large cheek teeth – large chewing muscles)
and the pelvis and leg bones resembled those of modern man. 
Females were smaller than males.

9. Australopithecus africanus
million years ago
appeared to be apelike
Light build; probably relatively long arms; more "human" features
Higher forehead; shorter face; brow ridges less prominent
protruding face
small brain,
distinctly unapelike dentition including small canines and large, flat molars. (large cheek teeth – large chewing muscles)
A bipedal posture was again indicated by the central position of the foramen magnum, and by the anatomy of the spine, pelvis, and femur.

10. Homo habilis Approx. 2.5 million years First definite human ancestor
1st member of genus homo
Larger brain
Presence of tools (indicates brain capable of complex thought)
Bi-pedal foot structure

11. Homo erectus 400, 000 y – 1.6 million years ago Larger brain capacity
Reduced size of face and cheek teeth
Thicker cranial bones
Bone limbs show little change

12. H. neanderthalensis 30, 000- 200, 000 years ago
similar to homo sapiens
Features related to cold climate adaptation
Broad bone and muscle structure
Short, strong body
Large, rounded nasal opening
Believed to be a genetical variant of H. sapien

13. H. sapien (archaic) 500 000 – 200 000 years ago
Skull became more rounded than H. erectus
Teeth are less thick and dense
Brow bridge still prominent
Much steeper forehead development of forebrain, planning, reasoning, speech.
Evidence of more complex tools

14. H. sapiens-modern man 1500-1600 years
highly developed brain and thus, mental capacity
social capabilities
less hair
less brow ridge,
jaw has decreased in size

16. Family Hominidae – determined by bipedialism
Trends in hominid evolution:
increasing adaptation to bipedalism, especially forward movement of foramen magnum
increasing brain size in relation to body size
decreasing relative size of: face, jaw, teeth, esp. canines; increasing relative size of brain case, forehead