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The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. The similarities among all known present-day species indicate that they have diverged through the process of ...
Earth is the only place in the universe known to harbor life, where it exists in multiple environments. The origin of life on Earth was at least 3.5 billion years ago, possibly as early as 3.8-4.1 billion years ago. Since its emergence, life has persisted in several geological environments.
The timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. Dates in this article are consensus estimates based on scientific evidence, mainly fossils . In biology, evolution is any change across successive generations in the heritable ...
Earth formed around 4.54 billion years ago, approximately one-third the age of the universe, by accretion from the solar nebula. [4] [5] [6] Volcanic outgassing probably created the primordial atmosphere and then the ocean, but the early atmosphere contained almost no oxygen.
Archean stromatolites are the first direct fossil traces of life on Earth. The earliest identifiable fossils consist of stromatolites, which are microbial mats formed in shallow water by cyanobacteria. The earliest stromatolites are found in 3.48 billion-year-old sandstone discovered in Western Australia.
Life’s Common Ancestor Lived 4.2 Billion Years Agoblackred - Getty Images. "Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." All life on Earth can be ...
Early Earth is loosely defined as encompassing Earth in its first one billion years, or gigayear (Ga, 10 9 y), [1] from its initial formation in the young Solar System at about 4.55 Ga to some time in the Archean eon in approximately 3.5 Ga. [2] On the geologic time scale, this comprises all of the Hadean eon, starting with the formation of the ...
The timeline of human evolution outlines the major events in the evolutionary lineage of the modern human species, Homo sapiens, throughout the history of life, beginning some 4 billion years ago down to recent evolution within H. sapiens during and since the Last Glacial Period . It includes brief explanations of the various taxonomic ranks in ...