Anthropology : Evolution of man
Similarities Of Man With Great Apes
- Bipedal Locomotion
- Absence of tail
- Social behaviour
- Large cranial capacities
- Similarity in molecular structure of insulin, cytochrome C and serum albumin
- Similarity up to 99% in amino acid sequence of α and β chains of hemoglobin.
- Similarity in nucleotide sequence of DNA.
- Similarity in banding pattern of chromosomes.
- 46 chromosomes of human beings have evolved from 48 chromosomes of apes by centromeric fusion.
Dissimilarities Of Man With Great Apes
- Face of man is Orthognathous (flat face) while it is Prognathous (projected face) in apes.
- Forelimbs of man are shorter than hind limbs but its just the opposite in apes.
- Brow ridges jaws are light in man but heavy in apes.
- Dental arch is C-shaped in man but U-shapes in apes.
- Lumbar curve is S-shaped in man but C-shaped in apes.
- Occipital condyles are adjusted in vertical orientation with backbone in man but horizontal orientation in apes.
Features acquired by man during its evolution from apes
- Perfect bipedalism.
- The thoracic cavity became barrel shaped and girdles improved in strength complemented with shortening of forelimbs.
- The lumbar vertebrae showed a reduction in number from 6-7 in apes to 5 in man.
- Lumbar curve changed from C-shaped to S-shaped.
- The sacral vertebrae showed fusion.
- The pelvis became broad and basin-like.
- The development of pronator and supinator muscles enabled man to rotate its wrists so that it could furnish and hurl weapons.
- Increase in cranial capacity from 400cc to 600 cc in apes to 1300-1400cc onwards in man.
- Increase in size of cerebral hemispheres.
- Change from prognathous face in apes to orthognathous face in man.
- Change in U-shaped dental arch in apes to C-shaped dental arch in man.
- Loss of simian gap (diastema) present in lower jaw of apes to accommodate long upper canines.
- Loss of body hair.
- Development of articulated speech so that man could communicate better.
DRYOPITHECUS- Its fossil was discovered by Louis Leakey from myosine rocks of Africa and Europe. It was ape-like but had arms and legs of same length. Heels in its feet indicated its semi-erect posture. It had a large brain (cranial capacity = 400 cc). It was arboreal, knuckle walker, without brow ridges and ate soft fruits and leaves. It had large canines.
SIVAPITHECUS- It was discovered from Shivalik hills of India from middle and late plyosine rocks. It also had a cranial capacity of 400cc.
RAMAPITHECUS (Sub man)- Its fossil was discovered by Edward Lewis. It belonged to myosine epoch and evolved from Dryopithecus. It could walk more or less erect, ate nuts, seeds and grasses and is hence commonly named as Nut-Cracker man. It is first man-like creature, termed sub man, and appeared to be on direct line of human evolution. Face was prognathous.
About 15 million years ago, Dryopithecus and Ramapithecus were existing on earth.
AUSTRALOPITHECUS (first ape-man or near-man)- It is considered as the connecting link between man and apes. It was discovered by Raymond Dart in 1924 from plyosine rock near Taung in Africa. The fossil was the skull of a 5-6 year old baby and hence it was termed as Taung baby. It was named as Australopithecus africanus. Australopithecines probably lived in the East African grasslands about 2 mya (million years ago). In 1981 Donald Johnson discovered a skeleton of a female human ancestor and named it Lucy. It was later scientifically as Australopithecus afarensis. It was characterized by the following features:
- height - 1.5 m
- bipedal locomotion
- somewhat erect posture
- diet essentially consisted of fruits though they used to hunt with stone weapons
- human like teeth but ape like brain
- cranial capacity : 400-600cc
- it lived in caves
- chin was absent as the face was prognathous
- it gave rise to Homo habilis
HOMO HABILIS (Able or Skilful man; Early Trueman; The Toolmaker or Handyman) - Its fossil was discovered by Lois Leakey and his wife Mary Leakey from Pleistocene rocks of Olduvai Gorge in East Africa. It was the first human like being. Its characteristic feature were:
- height : 1.2 - 1.5 m
- bipedal locomotion
- moved almost erect
- probably did not eat meat
- had light jaws with small canines like that of modern man
- cranial capacity = 650-800 cc
- first toolmaker and used tools of chipped stones extensively, named Oldovan tools
- lived in caves and cared for young ones.
HOMO ERECTUS (Erect man)- It is also called Middle Pleistocene Man as it evolved from Homo habilis in middle Pleistocene. It was characterized by:
- 1.5 - 1.8 m height with males probably larger than females.
- erect posture
- protruding jaws
- projecting brow ridges
- small canines and large molar teeth
- cranial capacity = 800-1300 cc
- made and used elaborate tools of stones and bones (called Echeulean tools)
- he hunted big games and perhaps knew use of fire
HOMO ERECTUS included 3 fossils:
1. Java ape man- It was discovered in 1891 by Eugene Dubois from Pleistocene rocks in central Java. He named it as Pithecanthropus erectus. Later in 1950, Mayor named it as Homo erectus erectus.
- Height: 1.65 - 1.75 m
- Legs were long and erect
- Forehead- low but brow ridges- high like apes
- cranial capacity= 800-1000 cc
- prognathous face
- omnivorous and cannibal
- it is said to have made use of fire for, hunting defense and cooking.
2. Peking man- It was discovered by W.C. Pei from limestone cave of Choukoutien near Peking. It was named by Davidson Black as Sinanthropus but Mayor named it as Homo eructus pekinensis. The difference of Peking man with Java man was its large cranial capacity of 800-1100 cc.
3. Heidelberg man- It was discovered in 1908 by Otto Schoetensack. It was named as Homo eructus heidelbergensis. Its cranial capacity was 1300 cc. Teeth were human like but jaws were massive, ape-like.
- Its fossils were obtained from Neander valley in Germany from late Pleistocene rocks by C. Fuhlrott.
- Lived in near East and Central Asia between 1,00,000-40,000 years back.
- It walked upright
- It was much more stockier than us
- cranial capacity = 1400 cc
- cave dweller
- had heavy brow ridges
- it was adapted to cold environment
- they used hides (thick tough skin of animals) as clothing and to protect their body from cold.
- it is said to have used fire for heating and illumination purposes.
- it buried its dead fellows ceremonially with flowers and tools and is said to have had a religion.
- It was discovered in 1868 from Cro-magnon rocks of France by Mac Gregor. It is regarded as the most ancestor of modern man.
- Emerged about 34,000 years ago.
- Height : 1.8 m
- Possessed well built body.
- Face was perfectly orthognathous with an elevated nose and broad and arched forehead.
- Man-like dentition.
- Well developed chin.
- Cranial capacity = 1650 cc (more than ours). It is therefore believed that cro-magnon man was somewhat more intelligent and cultured than us.
- It could walk and run faster.
- It lived with families in caves.
- made excellent tools (Aurignacean tolls) and ornaments not only of stones and bones but also of elephant tusks.
- It used clothes to cover body.
- A number of cave paintings have been discovered done by cro-magnon man
- It is considered direct ancestor of modern man!
They arose in Africa and moved across continents and developed as different races. Today's man evolved around 75,000-10,000 years ago. This age period was called ice-age (geological period of long term reduction in temperature of Earth).