Search results
Results From The WOW.Com Content Network
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]
The theory of evolution is widely accepted among the scientific community, serving to link the diverse speciality areas of biology. [19] Evolution provides the field of biology with a solid scientific base.
Evolution has been described as "fact and theory"; "fact, not theory"; "only a theory, not a fact"; "multiple theories, not fact"; and "neither fact, nor theory." [ 2 ] The disagreements among these statements, however, have more to do with the meaning of words than the substantial issues and this controversy is discussed below.
Darwinism is a term used to describe a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others. The theory states that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce.
In the so-called modern synthesis of the early 20th century, between 1918 and 1930 Ronald Fisher brought together Darwin's theory of evolution, with its insistence on natural selection, heredity, and variation, and Gregor Mendel's laws of genetics into a coherent structure for evolutionary biology. Biologists assumed that an organism was a ...
Evolution is the central unifying concept in biology. Biology can be divided into various ways. One way is by the level of biological organization, from molecular to cell, organism to population.
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).
Huxley recognized that unlike the earlier transmutational ideas of Jean-Baptiste Lamarck and Vestiges of the Natural History of Creation, Darwin's theory provided a mechanism for evolution without supernatural involvement, even if Huxley himself was not completely convinced that natural selection was the key evolutionary mechanism.