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Professor of biology Jerry Coyne sums up biological evolution succinctly: [3]. Life on Earth evolved gradually beginning with one primitive species – perhaps a self-replicating molecule – that lived more than 3.5 billion years ago; it then branched out over time, throwing off many new and diverse species; and the mechanism for most (but not all) of evolutionary change is natural selection.
The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]
Paleontologists have documented numerous transitional forms and have constructed "an astonishingly comprehensive record of the key transitions in animal evolution". [126] Conducting a survey of the paleontological literature, one would find that there is "abundant evidence for how all the major groups of animals are related, much of it in the ...
Darwin's theory of evolution is based on key facts and the inferences drawn from them, which biologist Ernst Mayr summarised as follows: [6] Every species is fertile enough that if all offspring survived to reproduce, the population would grow (fact). Despite periodic fluctuations, populations remain roughly the same size (fact).
Objections to evolution have been raised since evolutionary ideas came to prominence in the 19th century. When Charles Darwin published his 1859 book On the Origin of Species, his theory of evolution (the idea that species arose through descent with modification from a single common ancestor in a process driven by natural selection) initially met opposition from scientists with different ...
A key early discovery was that of homeotic genes that regulate development in a wide range of eukaryotes. The field is composed of multiple core evolutionary concepts. One is deep homology , the finding that dissimilar organs such as the eyes of insects , vertebrates and cephalopod molluscs, long thought to have evolved separately, are ...
The basic mechanisms of evolution are applied directly or indirectly to come up with novel designs or solve problems that are difficult to solve otherwise. The research generated in these applied fields, contribute towards progress, especially from work on evolution in computer science and engineering fields such as mechanical engineering. [5]