Social Studies

• Big Bang Theory


  Theory that the universe was born and developed in stages, and continues to change
• Big Bang


  1. Radio noise picked up by astronomers

  2. Princeton University acknowledged it as a distant echo of cosmos radiation

  3. Universe was born and developed in stages

  4. Universe continues to change
• The birth of planets is attributed to the big bang
• The earth was formed 4-6 billion years ago
• Radiometric dating


  Allows scientists to determine the ages of rock strata in thousands or millions of years before the present
• Radiometric dating process


  1. Calculation of when the decay process began based on certain radioactive isotopes such as potassium-40 to stable isotopes such as argon-40

  2. Decay of radioactive carbon-14 to stable carbon isotopes
• Continental drift


  The breaking apart of the single landmass Pangaea into the seven continents over eons, around 250-65 million years ago
• The theory of continental drift was concluded by German Meteorologist Alfred Wegener
• Plate tectonics


  The idea that the oceanic crust is constantly being formed by the extrusion and solidification of molten material from the earth's mantle along the lengths of the mid-ocean ridges
• The seven continents


  • Asia
  • Europe
  • North America
  • South America
  • Africa
  • Australia
  • Antarctica
• The formation of the continents has had a significant impact on the distribution of flora and fauna, and in evolution
• In 1871, Charles Darwin published the "Descent of Man" which forwarded the theory of evolution, speculating that men evolved from ape-like creatures
• In 1974, anthropologist Donald Johanson and Tom Gray discovered the skeleton of "Lucy", the oldest and most complete skeleton of any erect walking hominid, belonging to the genus Australopithecus Afarensis
• In 1959, Louis and Mary Leakey found a cranium referred to as a Zinjanthropus at Olduvai Gorge in Tanzania
• In 1978, clear ancient hominid footprints on volcanic ash were found by Mary Leakey's team in Laetoli, Tanzania, estimated to be 3.5 million years old
• Hominid


  The human family, distinguished by features like upright movement, large reorganized brain, diminished face and teeth, and the use and construction of tools
• Early types of hominid

  • Australopithecus Afarensis
  • Australopithecus Africanus
  • Australopithecus Robustus
  • Australopithecus Boisei
• Australopithecus Afarensis


  Our most ancient ancestor, dated 4 to 2.75 million years ago, with an average height of 1.2 meters and cranial capacity of 380 to 450 CC
• Australopithecus Africanus


  Dated 3 to 1.6 million years ago, with an average height of 1.4 meters and cranial capacity of 400 to 600 CC, may have used sticks and stones to gather food
• Australopithecus Robustus


  Dated 2.3 to 1.3 million years ago, had a larger cranium than previous hominids
• Australopithecus Boisei


  Dated 2.5 to 1.2 million years ago, had a skull similar to Robustus but with a ridge at the top
• Homo Habilis


  Generally believed to be the first human, dated around 2.4 million years old, the term means "handyman"
• Homo Erectus


  Dated 1.6 million years ago, originated in Eastern Africa, had a brain size of 800-900mL and was fully upright and bipedal, the first human type to spread from Africa to Asia
• Homo Sapiens


  Dated 400,000 years ago, had a larger braincase and expanded parietal region than Homo Erectus, developed more specialized tools and techniques like annealing, bow and arrow, spear-thrower, and systematic hunting
• Neanderthal man (Homo Sapien Neanderthalensis)


  An ancient variety of Homo Sapiens Sapiens, dated 100,000 to 30,000 BC, had a simple stone culture and were stocky in build
• Paleolithic Age


  Spanned from around 5 million years ago until about 10,000 BCE, known for the use of stone tools, small nomadic communities that foraged and hunted, developed fire and art
• Neolithic Age


  Spanned from 7,250 BCE to 6,500 BCE, marked by the agricultural revolution that freed humans from dependence on the environment, led to permanent shelters, domestication of animals, development of crafts, rituals and religious worship, and concepts of the afterlife
• Metal Age


  Transition from stone tools to the use of metals like copper, bronze, and iron, significant for the growth of civilizations, development of smelting process, use in agriculture, warfare, and trade
• Smelting


  The process of extracting metal from ore, first developed in Southwest Asia
• Bronze


  A tough metal made by mixing copper and tin, initially limited to the rich due to the expense of production
• Iron


  A cheap and abundant metal that was stronger than bronze, democratized access to improved agriculture and warfare, contributed to surplus production and trade, comparable to the industrial revolution