This term, coined by Richard Dawkins expresses a gene-centred view of evolution. The contention is that the genes that get passed on are the ones whose consequences serve their own implicit interests (to continue being replicated), not necessarily those of the organism.
In Dawkins theory, we cannot view the act of conception as replication of the full organism (human), the human is only a vehicle, made of replicators (genes). He defined a replicator as any entity in the universe of which copies are made. Until human cloning becomes a reality, humans as whole organisms cannot be seen as replicators, since a baby can never be a perfect copy of the parent. Therefore the human takes the role of a vehicle:
A vehicle is any unit, discrete enough to seem worth naming, which houses a collection of replicators and which works as a unit for the preservation and propagation of those replicators.” (Dawkins, The Extended Phenotype, 1982,p.114)
Dawkins writes that gene combinations which help an organism to survive and reproduce tend to also improve the gene’s own chances of being passed on and, as a result, frequently “successful” genes will also be beneficial to the organism. However there are other times when the implicit interests of the vehicle and replicator are in conflict, Another good example is the existence of segregation distortion genes that are detrimental to their host but nonetheless propagate themselves at its expense.
These genes are metaphorically described as “selfish” as they are dedicated to replicate and be represented in all next generations, regardless of the effect they might have on the whole organism - the vehicle. The adaptations are always for the benefit of the gene.
“Cancers are selfish cell lineages: clones of cells that, within an individual’s lifetime, have evolved high rates of replication compared to other clones, at the expense of the host fitness. They arise and spread by the conventional Darwinian process of repeated rounds of mutation and selection.” Burt and Trives, Genes in Conflict: The Biology of Selfish Genetic Elements)
These examples might suggest that there is a power-struggle between genes and their host. In fact, the claim is that there isn’t much of a struggle because the genes usually win without a fight. Only if the organism becomes intelligent enough to understand its own interests, as distinct from those of its genes, can there be true conflict. An example of this would be a person deciding to use contraception, even though their genes lose out due to this decision.
Can the selfish gene hypothesis exonerate a mutation transmitter from blame? Could that person be seen as simply an innocent vehicle controlled by the desires of their powerful selfish genes?
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