Evolution and Homology of Man – Zoology | Biology Grade XI

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Evolution-of-manBiology | Zoology Notes
Evolution and Homology of Man
For: Science Class 11

Evolution
The orderly and gradual change in object from one form to another form is called evolution. The orderly and gradual change in living things is organic evolution like plant evolution and animal evolution. The orderly and gradual change in non-living things is called inorganic evolution like the evolution of earth and stars.

Evolution of Man
Evolution of Early Mammal
About 210 million years ago, the early mammal evolved from the reptiles. They were small rat like animals having long snout. The Dinosaurs were also evolved from it.

Evolution of Primates
About 65 million years ago, primates evolved from the early mammal. The primates have long snout long and busy tail. It was insectivorous. It was like present day tree shrew. At that, time dinosaurs were extinct.

Evolution of Anthropoid Ape
About 36 million years ago anthropoid ape evolved from primates. They were ancestors of monkey, ape, and man. From the primates new world monkey diverged about 50 million years ago. The nose of the new world monkey’s nose was very flat, nostrils were directed upward, and tail is long and prehensile.

Evolution of Hominid
About 24 million years ago, the hominid evolved from anthropoid ape. The hominid was ancestors of man and ape. About 25 to 30 million years ago from the anthropoid ape old world monkey diverged. The old world monkey’s nose is raised, the nostrils directed downward and the tail is short and non-prehensile.

Evolution of Ramapithecus and Sivapithecus (the earliest ancestor of man)
About 10-14 million years ago, Ramapithacus and Sivapithecus evolved from the hominid. They were earliest ancestors of man. The Ramapithecus was found in Asia and Africa. Its tooth was found in Butwal of Nepal. The Sivapithecus was found in Asia. About 4-10 million years ago Apes diverged from the hominid. They include Chimpanzee, Gorilla, Orangutan, and Gibbon.

Evolution of Australopithecus
About 5 million years ago, the Australopithecus was evolved from the Ramapithecus and Sivapithecus. They were first human like animal. Their brain capacity was 400 – 600 cc. It could walk upright and about 3 – 5 ft tall and 40 – 50 Kg in weight. The Australopithecus has two species. They are A. Africans and A. robustus.

Evolution of Homo erectus
About 1.7 million years ago, Homo erectus evolved from A. africanus. The Homo erectus includes Java man found in Dubai and Pecking Man found in China. The Java man’s cranial capacity was 900 cc. It was 5 ft tall and used fire, tools. The locomotion was bipedal. The chin was absent. The Peking man’s cranial capacity was 1075 cc. It was supposed that Homo erectus was evolved from Homo habilis about 2 million years ago and the Homo habilis was evolved form A. Africanus. The Homo habilis cranial capacity was 700 cc. It was about 4-5 feet tall, bipedal, the chin was absent.

Evolution of the Cro-Magnon man
About 3400 years ago, the Cro-Magnon man evolved from Homo erectus. The Cro-Magnon man was like modern man. Their cranial capacity was 1600 cc. They were 5 ft tall, have prominent chin, broad or flat forehead, raised nose, superior intelligence. They made weapons, lived in caves and he was artist.

Evolution of Neanderthal man
About 70-40 thousand years ago, The Neanderthal man Homo sapiens neanderthalensis diverged from Homo erectus. Their cranial capacity was 1450 cc. They resemble to modern man. They were 5 ft tall, chin was absent, they used tools for hunting used animal hides as clothes, capable of communicating, and they made tradition to bury dead bodies.

Evolution of Modern man
The modern man (Homo sapiens) evolved about 10000 years ago from the Cro-Magnon man. The modern man has changed from cave dwelling hunting life to the crop raising life. It started cultivated plants, domesticated animals, and brought about the Cultural Revolution with its superior intelligence.

Differences between Ape and Man
Ape

  1. The apes have semi erect body
  2. The vertebral column is curved
  3. The bipedal locomotion need support of forelimb
  4. The fore limb is longer than hind limb
  5. The thumb does not extend up to the base of fore finger.
  6. They have flat nose
  7. Canine incisor teeth are longer and thicker
  8. The chin is absent
  9. The eye brow ridges are heavy and prominent
  10. They have short neck embedded in shoulder
  11. The body is covered with hairs

Man

  1. The man has erect body
  2. Vertebral column is straight
  3. The bipedal locomotion do not need support of fore limb
  4. The fore limb is shorter than the hind limb
  5. The thumb extends up to the base of fore finger
  6. They have raised nose
  7. The canine and incisor teeth are shorter
  8. The chin is prominent
  9. The Eye brow ridges are not so prominent
  10. They have long neck
  11. Fewer amounts of hairs are present on the body.

Homology of Man

  1. Similarities in chromosome number of apes and man is called homology.
  2. The chromosomes number of apes is 48.
  3. The chromosome number of man is 46.
  4. Similar amount of DNA.
  5. Banding pattern of chromosome is similar.
  6. Chromosome number 3, 6 have similar banding pattern
  7. Banding pattern means arrangement of DNA in chromosome.

Posted By : Hari Prasad Chaudhary | Comment RSS | Category : Class XI, HSEB Notes
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