## Definition **The selfish gene** is the metaphor and conceptual argument, introduced by Richard Dawkins in 1976, that genes behave *as if* they were selfish agents maximising their own replication — not because genes have intentions, but because any heritable variant that systematically increases its own copying frequency will, by definition, spread through a population. "Selfishness" here is entirely metaphorical: it describes the logical outcome of selection, not a psychological state. ## The Argument Natural selection retains whatever heritable variants produce more copies of themselves. Over many generations this creates the *appearance* of design: genes have been "sculpted" by selection to produce traits — morphological, physiological, behavioural — that enhance gene propagation. A gene that causes its carrier to sacrifice fitness for unrelated organisms would be diluted in every generation and could not persist. Hence surviving genes are, in the only sense that matters to evolution, selfish. The key passage from Dawkins: > "The fundamental unit of selection, and therefore of self-interest, is not the species, nor the group, nor even, strictly speaking, the individual. It is the gene, the unit of heredity." ## Selfishness Does Not Mean Cruelty The gene-centred lens predicts altruism as readily as aggression, whenever altruism serves gene propagation: - **Kin altruism:** helping relatives who share copies of the same gene (see [[Kin Selection and Inclusive Fitness]]). - **Reciprocal altruism:** cooperating with non-relatives when the exchange is repeated and defection is punishable (see [[Evolutionarily Stable Strategy]]). - **Apparent altruism within groups:** may reflect hidden kin structure, or simply that group membership confers individual survival benefits. None of these require "group benefit" as an explanatory primitive; all reduce to gene-level accounting. ## Survival Machines Genes operate indirectly. They cannot act in real time — protein synthesis is too slow to respond to a predator. Instead they have built *survival machines*: bodies equipped with sensory organs, nervous systems, and brains capable of rapid response. The brain may even run internal simulations (imagination) to predict consequences before acting. Human consciousness, on this view, may be the most extreme form of emancipation of the survival machine from immediate gene control: we can choose to use contraception, a goal entirely contrary to gene interests. ## Alleles as Competitors At any gene locus, alternative forms (alleles) compete for representation. Even a small fitness advantage — say, 1% better survival per generation — is sufficient to drive an allele to near-fixation within a few thousand generations. This arithmetic is the engine behind adaptation. ## Related - [[Gene-Centred View of Evolution]] - [[Replicator and Vehicle]] - [[Kin Selection and Inclusive Fitness]] - [[Evolutionarily Stable Strategy]] - [[Extended Phenotype]] ## Sources - [[The Extended Selfish Gene (Dawkins 2016)]]