Julius Rebek and coworkers demonstrated one of the first: a synthetic molecule that could act as the template for its own replication. It is not clear that a gene can be considered, from a chemical point of view, a replicator. I will go out on a limb and say that I don’t believe anyone has ever observed a gene, as a discrete and autonomous unit, make an exact copy of itself, whether or not it is in a pool of such copies.
Genes, but no other units in life’s hierarchy, make exact copies of themselves in a pool of such copies.’ Groups, meanwhile, do not make exact copies of themselves. Wilson ignores, argues Dawkins, that the gene ‘is on its own as a “replicator”, with its own unique status as a unit of Darwinian selection. This challenges Dawkins’ gene-centred view. Wilson for the latter’s advocacy of group selection: the idea that natural selection works at the level of groups of organisms (and presumably at other levels in the biological hierarchy from gene to ecosystem). Perhaps Dawkins’ most trenchant statement to that effect was in an attack on Harvard biologist E. But the fundamental premise on which it is built – DNA as replicator – seemed always to be sound. ‘We are,’ he famously said, ‘all survival machines for the same kind of replicator – molecules called DNA.’ Battles have been fought over whether this is a good use of metaphor (and as with the ‘selfish gene’ itself, metaphor was all it was ever meant to be). Richard Dawkins’ 1976 book The selfish gene, which topped a poll last year for the most inspiring science books of all time, has set the agenda for how we think about genes and DNA.
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