８４ The History of the Earth

８４　The History of the Earth

13.7 billion years ago   Big Bang
13.5 billion years ago   Birth of stars
10 billion years ago The birth of the Milky Way galaxy
4.6 billion years ago　　Formation of The Solar system and Earth (primitive atmosphere is mostly hydrogen and helium).
4.3-4.0 billion years ago 　Ocean was born
3.8 billion years ago      Birth of unicellular organisms
2.4～2.1 billion years ago  The oldest ice age. （Huronian glaciation）
750～700 million years ago  Sturtian glaciations
640 million years ago     Marinoan glaciation・・・Snowball Earth
600 million years ago     Birth and explosion of multicellular organisms（the Cambrian）
500 million years ago　　Creature won the brain.
460～430 million years ago  Little ice age(Andean-Saharan glaciation)
400 million years ago     Plants advanced the land from the sea.
360 million years ago     Animal’s landing
360 ～260 million years ago  Expansion period of glacier( Karoo Ice Age）
300 million years ago 　　Increase of insects (cockroaches = living fossil)
Emergence of reptiles
250 million years ago     Mass extinction of lives (Permian)
Emergence of dinosaurs
225 million years ago　　 Emergence of mammals
220 million years ago 　　Mass extinction of lives
150 million years ago 　　Emergence of archaeopteryx
140 million years ago 　　Division of Australian continent
100 million years ago  　Golden age of dinosaurs (The average temperature was about 23℃. Temperature of current average is 15℃.)
65 million years ago  A mass extinction of organisms= Extinction of dinosaurs(Collision of comet(about 10km diameter))
Emergence of primates(Ability to synthesize vitamin C is lost)
40 million years ago   Last ice age
25 million years ago    The oldest fossil that seems to be apes
10 million ～5 million years ago    The formation of the Great Rift Valley in Africa began.
about 6 million ～ 5 million years ago   The differentiation of Humans and chimpanzees
about 2.5 million ～ 1.8 million years ago　　Start of Stone tools
1.7 million years ago　　Human beings born
0.5 million years ago　　Peking man
230,000 years ago 　　 Emergence of Neanderthals ・・・Use of stone tools
200,000 ～190,000 years ago  　Emergence of Homo sapiens (present people)
160,000 ± 40,000 years ago 　 Mitochondrial Eve in Africa
(150 000 years ago 　 polar bear and brown bear was divided)
100,000 years ago～    Modern humans (Homo sapiens) were spread out of the Africa.
 (It was lower about 5-8 degrees in average temperature than the current：The difference between the annual average temperature in Tokyo and Sapporo. Sea level was 120m lower than now. )
70,000 years ago ～ 　The last ice age
10,000 years ago　　　The end of the last ice age
30,000 years ago 　 Extinction of Neanderthal
30,000 ～ 20,000 years ago    Mongoloid passed to the Americas.
14,000 ～10,000 years ago    Humanity tamed the dog.
13 000 years ago  　Japanese archipelago became the island.
10,000 years ago 　　　　 The end of the last ice age
20th century　　Development of science and technology, the explosive growth of population, globalization, world war, environmental destruction and resource depletion concerns
The 21st century 　　 Nuclear fusion power generation. Development of Artificial intelligence, Biotechnology and Nanotechnology. Multi-polar world.