The gene-centric view of evolution or gene selection theory holds that evolution can be viewed as acting only at the level of genes, and that selection on higher units such as populations and species (group selection) is negligible. In particular, it holds that selection on higher levels such as organisms and populations almost never opposes selection on genes. Charles Darwin, the father of modern evolutionary theory In the life sciences, evolution is a change in the traits of living organisms over generations, including the emergence of new species. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... In biology, a species is a kind of organism. ... In evolutionary biology, Group selection refers to the idea that alleles can become fixed or spread in a population because of the benefits they bestow on groups, regardless of the fitness of individuals within that group. ...

The view draws on the mathematical evolutionary biology of the early 20th Century developed by Ronald Fisher and others, and was expounded George C. Williams. Its most notable later exponent was the British biologist W.D. Hamilton. Hamilton's friend Richard Dawkins popularized it in his book The Selfish Gene. (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999 in the... Sir Ronald Fisher Sir Ronald Aylmer Fisher, FRS (February 17, 1890 – July 29, 1962) was an evolutionary biologist, geneticist and statistician. ... Professor George C. Williams is emeritus professor of biology at the State University of New York at Stony Brook. ... This article is about the British biologist Bill Hamilton. ... Dawkins is the holder of the Charles Simonyi Chair in the Public Understanding of Science at the University of Oxford. ... The Selfish Gene is a controversial book by Richard Dawkins published in 1976. ...

One reason for the wide acceptance of the idea was that evolutionary models in the 1960s seemed to suggest that selection at higher levels had to be extremely weak. However, in the last decade, much theoretical work has shown that multi-level selection is indeed possible. Events and trends The 1960s was a turbulent decade of change around the world. ...

The gene-centric view has also been criticised for being inappropriately reductionist. In recent years, partially as a consequence of the influence of ideas from the study of complex systems, this view has become less dominant, and interaction between genes and between organisms as a force in evolution has become a topic of research. Reductionism in philosophy describes a number of related, contentious theories that hold, very roughly, that the nature of complex things can always be reduced to (explained by) simpler or more fundamental things. ... Complex systems have a number of properties, some of which are listed below. ...