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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.
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.
Life - Evolution, History, Earth: The evidence is overwhelming that all life on Earth has evolved from common ancestors in an unbroken chain since its origin. Darwin’s principle of evolution is summarized by the following facts.
The origin of life on Earth stands as one of the great mysteries of science. Various answers have been proposed, all of which remain unverified. To find out if we are alone in the galaxy, we will need to better understand what geochemical conditions nurtured the first life forms.
Here are 3 popular theories. The first signs of microbial life emerged around 3.5 billion years ago. Scientists think early life may have formed from lighting strikes or arisen in deep sea...
But a true understanding of life, on Earth or some other world, likely will require us to unravel even earlier beginnings: the ignition of stars with their freight of life’s building blocks, the formation of planets from protoplanetary disks, the energy and chemistry of surfaces and atmospheres.
Therefore, the earliest time for the origin of life on Earth is at most 3.5 billion years ago, possibly as early as 4.1 billion years ago — not long after the oceans formed 4.5 billion years ago and after the formation of the Earth 4.54 billion years ago.
The story of evolution spans over 3 billion years and shows how microscopic single-celled organisms transformed Earth and gave rise to complex organisms like animals
The Origin of Life on Earth. Fresh clues hint at how the first living organisms arose from inanimate matter. By Alonso Ricardo & Jack W. Szostak. September 2009 Issue. The Sciences. Every living...
Life arose on the early Earth by a series of progressive chemical reactions. Such reactions may have been likely or may have required one or more highly improbable chemical events.