In evolutionary biology, a group of organisms share common descent if they have a common ancestor. There is strong quantitative support for the theory that all living organisms on Earth are descended from a common ancestor.
Charles Darwin proposed the theory of universal common descent through an evolutionary process in On the Origin of Species, twice stating the hypothesis that there was only one progenitor for all life forms and ending with "There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one". The theory asserts that all currently living organisms on Earth share a common genetic heritage with each being the descendant from a single original species, though the suggestion of substantial horizontal gene transfer during early evolution has led to questions about monophyly of life.
The last universal ancestor (LUA) (also called the last universal common ancestor, LUCA), that is, the most recent common ancestor of all currently living organisms, is believed to have appeared about 3.9 billion years ago.
Other articles related to "common descent, common":
... Unlike Lamarck, Darwin proposed common descent and a branching tree of life, meaning that two very different species could share a common ancestor ... Part of a series on Evolutionary biology Key topics Introduction to evolution Common descent Evidence of common descent Processes and outcomes Population genetics ...
... Further information Common descent and Evidence of common descent All organisms on Earth are descended from a common ancestor or ancestral gene pool ... The common descent of organisms was first deduced from four simple facts about organisms First, they have geographic distributions that cannot be explained by local adaptation ... prokaryotes such as bacteria and archaea share a limited set of common morphologies, their fossils do not provide information on their ancestry ...
... of a coherent relationship of three related ideas common descent, natural selection, and random mutation ... ideas, with implications for the theory as a whole common descent and natural selection he accepts without question but questions the scope and power of random mutation ... Behe argues strongly for common descent of all lifeforms on earth, including that humans and chimpanzees have a common ancestor ...
Famous quotes containing the words descent and/or common:
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