The Selfish Gene is a book on evolution

Evolution

Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

 by Richard Dawkins

Richard Dawkins

Clinton Richard Dawkins, FRS, FRSL , known as Richard Dawkins, is a British ethologist, evolutionary biologist and author...

, published in 1976

1976 in literature

The year 1976 in literature involved some significant events and new books.-Events:* Saul Bellow won both the Nobel Prize for Literature and the Pulitzer Prize for Fiction.-New books:*Kingsley Amis – The Alteration...

. It builds upon the principal theory of George C. Williams

George C. Williams

Professor George Christopher Williams was an American evolutionary biologist.Williams was a professor emeritus of biology at the State University of New York at Stony Brook. He was best known for his vigorous critique of group selection. The work of Williams in this area, along with W. D...

's first book Adaptation and Natural Selection

Adaptation and Natural Selection

Adaptation and Natural Selection: A Critique of Some Current Evolutionary Thought is a 1966 book by the American evolutionary biologist George C. Williams...

. Dawkins coined the term "selfish gene" as a way of expressing the gene-centred view of evolution

Gene-centered view of evolution

The gene-centered view of evolution, gene selection theory or selfish gene theory holds that evolution occurs through the differential survival of competing genes, increasing the frequency of those alleles whose phenotypic effects successfully promote their own propagation, with gene defined as...

 as opposed to the views focused on the organism and the group

Group selection

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 alleles' effect on the fitness of individuals within that group....

. From the gene-centred view follows that the more two individuals are genetically related, the more sense (at the level of the genes) it makes for them to behave selflessly with each other.