Monday, 24 January 2011

The General Theory of Genetic Priming

I suggest that:-

All living things, both animals and plants, are genetically primed to manifest behaviour that has been adaptive for their species.

Some adaptive behaviour, and this applies to animal neonates in particular, may be directly coded into the genome and may be manifested without an environmental trigger. These are usually called instincts. An example would be the rooting behaviour of mammalian neonates. An alternative interpretation of this rooting behaviour would be that it is genetically primed and triggered by the neonate sensing the breast. Most adaptive behaviours are indeed primed and need to be environmentally triggered. An example would be language in humans.

Since there are invariably multiple genetically primed behaviours, involving overlapping sets of genes, the gene variants primed for any particular adaptive behaviour will tend to be suboptimal for that behaviour but optimal for the complete set of adaptive behaviours and any other genetically mediated faculties that involve that set of gene variants.

Genetic priming can be proved deductively as follows. Any new adaptive behaviour in generation n will be positively associated with particular sets of gene variants. Those variants will be relatively over-represented in the following generation (n+1) due to the positive association. This will mean that the adaptive behaviour will increase in frequency in the same generation. This will lead to those same sets of gene variants increasing in frequency in generation (n+2). This process will continue over evolutionary time until all members of the species have the set of gene variants that are positively associated with the adaptive behaviour which will leave them primed to manifest that behaviour.

A few additional examples of genetic priming: birds are genetically primed to build nests, plants are genetically primed to grow toward sunlight and humans are primed for religiosity.

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