Course of evolution of modern man

• Fossils of past life or ancestral forms of modern man revealed a lot of features of our ancestors.
• Man is thought to evolve from ape like ancestors and showed a gradually change in features during evolution from ape to man.

You may also want to see: Differences between Man and Apes

• Different ancestral forms of modern man during the course of evolution are as follows:
  1. Propliopithecus and Aegyptopithecus:
     • Fossil of this form discovered from Egypt is supposed to be 3 crore years old. It was more Ape-like.
     • Fossils are represented by jaw and teeth.
     • Dental formula : I=2, C=1, PM=2, M=3
     • The lower molar had 5 cusps.
  2. Dryopithecus or Proconsul:
     • Fossil was discovered from east Africa by Dr. Leaky.
     • The fossil of this form is morphologically intermediate between ape and man, showing a rounded man-like forehead and long pointed ape like canines.
     • According to some anthropologist, their fossils represent about the stage of development at which primitive man and primitive apes diverged from ancestral primates.
     • The skull is estimated by geochemical techniques as being about 25 million years old.
  3. Subman (Kenyapithecus wickeri- Ramapithecus):
     • The early Pliocene prehuman remains (part of upper jaw) was discovered by Leaky and associates from Africa, in 1962.
     • It was not associated with any evidence of tools.
     • Humanoid features include the small canine teeth and canine fossae.
  4. Australopithecus:
     • In 1924, Raymond Dart in South Africa discovered a skull of an infant which he named as Australopithecus africanus.
     • In 1936, Robert Broom found a second, but adult skull near Johannesburg, South Africa. Minor differences caused it to be named as Australopithecus transvalensis.
     • Like modern man they were fully first bipedal and walked upright.
     • They were about 5 feet tall.
     • They had low forehead and low brain volumes or cranial capacity (about 450-550 cc).
     • They lived in caves and hunted animals, but no evidence of the use of tools or fire.
     • More recent discoveries include a tibia and fibula. Based on geochemical methods, surrounding sediments have been estimated to be 1.75 million years old.
     • Omnivorous and used bones for hunting.
  5. Handy man (Homo habilis):
     • It was discovered from east Africa by Mr. and Mrs. Leaky.
     • They were first tool maker man, nut cracker man who made tools from stones.
  6. Upright man (Homo erectus):
     • They existed in the Pleistocene epoch.
     • They were of further two types:

                a. Java ape-man (Pithecanthropus erectus):

• • It was first discovered in Trinil, Java in 1891, by Eugene Dubois.
  • There are currently four skulls as well as several associated bones.
  • The skull bone and eye brow ridges were heavy.
  • The brain volume range from 750 to 900 cc.
  • The shapes of the limbs suggest a semi-erect posture.
  • No signs of the use of tools have been associated with these fossils.
  • They used fire for cooking.

                 b. Peking man (Sinanthropus pekinensis):

• • First discovered in 1903 by Davidson Black and W.C. Pei near Peking, China.
  • It is so similar to the Java man that is now generally agreed that the two should be grouped as members of the same species.
  • Brain volumes range from 915 to 1220 cc, averaging just over 1075 cc.
  • The fossils are associated with primitive tools (stone and bone) and evidence of use of fire.

7. Early true man (Early Homo sapiens):
   • A number of fossil of men of mid and late Pleistocene age have been associated with tools and other signs of culture.
   • Others are known only as isolated fragments.
   • Some may actually be on the direct line of human ancestry, but others appear to represent specialized side branches, which are as follows:
     • Heidelberg man is known only from one complete mandible found near Heidelberg Germany in 1907.The jaw is stronger and more massive than that of any living men. The fossil was not associated with tools.
     • Swabscombe man was discovered in England in 1935, and has been associated with stone implements.
     • Steinheim man was discovered in Germany in 1993.
     • Ehringsdorf man, discovered in Germany, is noted for having an unusually large brain capacity, even when compared to modern man.

8. Neanderthal man (Homo neanderthalensis):
   • The early man lived in caves and rock shelters in southern Europe and central Asia.
   • The cranium is flattened, the forehead sloping, and the brow ridges heavy.
   • The cranial capacity ranges from 1300 to 1600 cc.
   • Neanderthals believed in ‘immortality of soul’ and did ceremonial burl for the first time.
   • Often associated with tools and evidences of fire.
   • They had a social structure and customs and probably a religion.
   • They built huts and used animal hides as clothing.
   • Rhodesian man (Homo rhodesiensis), were discovered from a cave at Broken Hill, Rhodesia, in South Africa. Solo man (Homo soloensis), were disovered from Java.
9. Cro-magnon man (Homo sapiens):
   • Cro-magnon man was the immediate ancestor of modern man.
   • It was the first chin man and used bows and arrows.
   • The forehead and cranium were high, the brain size large (averaging about 1590 cc).
   • The body was tall (males averaging 70 inches) and robust.
   • These men used tools and made sculptures and color paintings often in caves.
10. Modern man (Homo sapiens sapiens):
    • They have lighter build of their skeleton compared to earlier humans.
    • They have a large brain averaging about 1300 cc cranial capacity.
    • Flat and nearly vertical forehead.
    • Lighter jaws and smaller teeth.
    • The center of origin of modern man appears to have been in Asia, in the general region of the Caspian Sea.
    • The white races spread westward around both shores of the Mediterranean to Europe.
    • The Negroid races spread south on both sides of Indian Ocean to Africa and Malanesia. It is considered that they too displaced primitive races and pushed the Bushman to the tip of South Africa and the Australoids into Australia.
    • The mongoloids spread eastwards and northwards occupying Siberia and China and then to North and South America.
    • These are the four basic stocks of modern man, all of which belongs to the species of Homo sapiens. Of all these, the Australian are thought to be the most primitive.
    • The other three, the mongoloids, negroids and whites are further subdivided into races.
    • A race is defined as a population which differs significantly from the other with respect to the frequency of one or more genes it contains.
    • Phenotypically the members of a race are distinguished as a group by a combination of morphological and physiological characteristics which they share because of their inheritance from a common ancestor.

Course of evolution of man from ape-like ancestors:

• • Man has increased slightly in height.
  • He can now stand erect and his head is balanced on a relatively slender neck.
  • His cranial capacity has increased, the frontal lobes of the brain have enlarged and the skull is more rounded.
  • Speech is invented; tools and weapons were made.
  • The man started living in clans and tribes and exhibited tremendous progress in social life.

Course of evolution of modern man