| abstract | - This timeline of the evolution of life outlines the major events in the development of life on the planet Earth. For context, see geologic time scale, and the history of Earth. Dates given are estimates based on scientific evidence. The table uses the symbols "Ma" for "mega-annum (million years ago)" and "ka" for "kilo-annum (thousand years ago)". English literature also uses the abbreviations "mya" (m.y.a) and "tya" (t.y.a) or "kya" in the same sense. In biology, evolution is the process by which populations of organisms acquire and pass on novel traits from generation to generation. Its occurrence over large stretches of time explains the origin of new species and ultimately the vast diversity of the biological world. Contemporary species are related to each other through common descent, products of evolution and speciation over billions of years. The basic timeline is a 4600 million year old Earth, with
* 4000 my (million years) of simple cells,
* 3000 my of photosynthesis,
* 2000 my of complex cells,
* 1000 my of multicellular life,
* 600 my of simple animals,
* 500 my of fish and proto-amphibians,
* 475 my of land plants,
* 400 my of insects and seeds,
* 360 my of amphibians,
* 300 my of reptiles,
* 200 my of mammals,
* 150 my of birds,
* 100 my of flowers and
* 65 my since the non-avian dinosaurs died out. For a list of our common ancestors with other living species, see The Ancestor's Tale.
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