मराठी

Revision: Genetics and Evolution >> Human Evolution Biology (Theory) ISC (Science) ISC Class 12 CISCE

Advertisements

Key Points

Key Points: Early Human Ancestors
  • Scientific discussions in the nineteenth century by Thomas Huxley and Charles Darwin established the foundational evolutionary relationship between humans and apes.
  • Humans, scientifically classified as Homo sapiens, belong to the order Primates and the family Hominidae within the animal kingdom.
  • The evolutionary development of early human ancestors is primarily studied through fossilised skeletal remains, including bones, jaws, teeth, and skulls.
  • Dryopithecus represents an early, predominantly ape-like ancestor characterised by a semi-erect posture, a projecting face, and heavy jaws.
  • Ramapithecus represents a later, more human-like ancestor distinguished by an upright face, smaller, delicate jaws, and a semi-circular dental arcade.
Key Points: The Ape Man
Feature Australopithecus africanus Homo habilis Homo erectus
Discoverer Raymond Dart (1924) Louis Leakey (1960) Eugène Dubois (1891)
Geological age Pliocene–Pleistocene (~2 mya) Pleistocene (1.6–1.8 mya) Pleistocene (~1.7 mya)
Place Taung, Africa Olduvai Gorge, Africa Java; also China & Africa
Height ~150 cm 120–150 cm ~150 cm
Cranial capacity ~600 cm³ ~680 cm³ ~900 cm³
Posture Almost erect Fully erect Fully erect
Jaw & teeth Human-like teeth, no chin Lighter jaw, modern dentition Heavy jaw, large teeth, no chin
Diet Omnivorous Omnivorous Omnivorous
Tools Used pebbles/bones First stone tool-maker Advanced tools, used fire
Significance Early hominid “Handy man” Direct ancestor of modern man
Key Points: The Early Man
 
Feature Neanderthal Man Cro-Magnon Man Modern Man
Scientific name Homo sapiens neanderthalensis  Homo sapiens fossilis  Homo sapiens sapiens 
Time period 150,000–25,000 years ago  50,000–20,000 years ago  About 11,000 years ago to the present 
Discovery Neanderthal Valley, Germany, 1856  Cro-Magnon, France, 1868  Fossils from France, Java, and South Africa 
Height and build Short, stout, powerful  Tall, strong, about 180 cm  Variable, generally balanced body form 
Cranial capacity About 1450 cm³  About 1660 cm³  About 1350–1400 cm³ 
Skull characters Low forehead, heavy brow ridges, no chin  Higher forehead, reduced brow ridges, chin present  High forehead, reduced brow ridges, well-developed chin 
Lifestyle Cave dweller, nomadic  Hunter, cave dweller, more organised  Settled life, agriculture, domestication 
Tools Flint tools  Advanced stone tools, ornaments  Highly advanced technology 
Culture Buried dead, primitive communication  Art, ornaments, beliefs  Language, culture, civilization 
Status Extinct  Closer to modern humans  Present-day humans 
Key Points: Man vs Ape
Feature Man Ape
Habitat & Posture Terrestrial; walks fully erect on the soles of its feet. Chiefly arboreal; walks semi-erect on knuckles and outer edges of feet.
Limbs & Grasping Hind limbs are stronger and longer; only the thumb is opposable. Forelimbs are longer; both the thumb and big toe are opposable.
Spine & Skull Base Spine has a lumbar curve (facilitates erect posture); foramen magnum is directed downward. Spine is arched backwards (no lumbar curve); foramen magnum is directed backwards.
Face & Jaws Flat face, prominent chin, small canines, and no tooth gap (diastema). Protruding face, prominent brow ridges, no chin, and a tooth gap (diastema) are present.
General Brain Size Rounded cranium averaging about 1450 cm³. Flattened cranium averaging under 650 cm³.
Evolutionary Cranial Capacities

Homo habilis: 680 cm³

Gibbon: 100 cm³

Homo erectus: 900 cm³

Orangutan: 395 cm³

Neanderthal man: 1450 cm³

Chimpanzee: 400 cm³

Cro-Magnon man: 1660 cm³

Gorilla: 510 cm³

Homo sapiens sapiens: 1450 cm³

Australopithecus: 600 cm³

Advanced Abilities Can make and use tools; possesses speech and written language. Lacks advanced tool-making, speech, and writing abilities.
Key Points: Stages of Human Evolution
 
Ancestor/Stage Approximate Time Posture Cranial Development Distinctive Features
Dryopithecus 20–25 million years ago Ape-like Low Early primate, arboreal traits 
Ramapithecus 14–12 million years ago More advanced than earlier apes Slightly improved More man-like jaw and teeth features
Australopithecus 4–1.8 million years ago Semi-erect to upright Small Early bipedal tendency, lived in open habitats
Homo habilis 2.5–1.4 million years ago More upright Increased Tool use, early Homo stage
Homo erectus About 1.5 million years ago Erect Higher Better tools, use of fire, and stronger adaptation
Neanderthal man 100,000–40,000 years ago Erect Advanced Hunting, burial practices, and social behaviour
Cro-Magnon man Later prehistoric period Erect Highly developed Art, improved culture, and advanced skills
Modern Homo sapiens Present form Fully erect Most advanced Language, reasoning, culture, technology
Key Points: Social Evolution and Future Man
  • Human social evolution features the establishment of stable families, prolonged childhood, and advanced speech.
  • Survival advanced through cooperative food-gathering, shared home bases, and division of labour by age and sex.
  • Technological and cultural progress included complex tools, mastery of fire, geographic expansion, and the development of arts and sciences.
  • Anthropologist Sapiro predicts modern humans will naturally evolve into a future species named Homo sapiens futuris.
  • This future human is predicted to be taller and completely hairless, lacking a fifth toe, with a tomb-like head for a larger brain.
Advertisements
Advertisements
Advertisements
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×