|Big Bang||January 1|
|Origin of Milky Way Galaxy||May 1|
|Origin of the solar system||September 9|
|Formation of the Earth||September 14|
|Origin of life on Earth||~ September 25|
|Formation of the oldest rocks known on Earth||October 2|
|Date of oldest fossils (bacteria and blue-green algae)||October 9|
|Invention of sex (by microorganisms)||~ November 1|
|Oldest fossil photosynthetic plants||November 12|
|Eukaryotes (first cells with nuclei) flourish||November 15|
Significant oxygen atmosphere begins to develop on Earth.
Extensive vulcanism and channel formation on Mars.
Precambrian ends. Paleozoic Era and Cambrian Period begin. Invertebrates flourish.
First oceanic plankton. Trilobites flourish.
Ordovician Period. First fish, first vertebrates.
Silurian Period. First vascular plants. Plants begin colonization of land.
Devonian Period begins. First insects. Animals begin colonization of land.
First amphibians. First winged insects.
Carboniferous Period. First trees. First reptiles.
Permian Period begins. First dinosaurs.
Paleozoic Era ends. Mesozoic Era Begins.
Triassic Period. First mammals.
Jurassic Period. First birds.
Cretaceous Period. First flowers. Dinosaurs become extinct.
Mesozoic Era ends. Cenozoic Era and Tertiary Period begin. First cetaceans. First primates.
First evolution of frontal lobes in the brains of primates. First hominids. Giant mammals flourish.
End of Pliocene Period. Quaternary (Pleistocene and Holocene) Period. First humans.
|Origin of Proconsul and Ramapithecus, probable ancestors of apes and men||~ 1:30 p.m.|
|First humans||~ 10:30 p.m.|
|Widespread use of stone tools||11:00 p.m.|
|Domestication of fire by Peking man||11:46 p.m.|
|Beginning of most recent glacial period||11:56 p.m.|
|Seafarers settle Australia||11:58 p.m.|
|Extensive cave painting in Europe||11:59 p.m.|
|Invention of agriculture||11:59:20 p.m.|
|Neolithic civilization; first cities||11:59:35 p.m.|
|First dynasties in Sumer, Ebla and Egypt; development of astronomy||11:59:50 p.m.|
|Invention of the alphabet; Akkadian Empire||11:59:51 p.m.|
|Hammurabic legal codes in Babylon; Middle Kingdom in Egypt||11:59:52 p.m.|
|Bronze metallurgy; Mycenaean culture; Trojan War; Olmec culture; invention of the compass||11:59:53 p.m.|
|Iron metallurgy; First Assyrian Empire; Kingdom of Israel; founding of Carthage by Phoenicia||11:59:54 p.m.|
|Asokan India; Ch'in Dynasty China; Periclean Athens; birth of Buddha||11:59:55 p.m.|
|Euclidean geometry; Archimedean physics; Ptolemaic astronomy; Roman Empire; birth of Christ||11:59:56 p.m.|
|Zero and decimals invented in Indian arithmetic; Rome falls; Moslem conquests||11:59:57 p.m.|
|Mayan civilization; Sung Dynasty China; Byzantine empire; Mongol invasion; Crusades||11:59:58 p.m.|
|Renaissance in Europe; voyages of discovery from Europe and from Ming Dynasty China; emergence of the experimental method in science||11:59:59 p.m.|
|Widespread development of science and technology; emergence of global culture; acquisition of the means of self-destruction of the human species; first steps in spacecraft planetary exploration and the search of extraterrestrial intelligence||Now: The first second of New Year's Day|