I commented on a post of Johnnie Moore’s a couple of weeks ago, along the line of meme’s being mimicked by their own analogue, genes – as funghi, bacteria, virus infections, etc – affecting (human) host brain behaviour. The cordyceps fungal infections of insects are used by Dennett to illustrate meme behaviour.
Over the weekend another post from Neurophilosophy along the same lines. The common ground is the bacteria causing risk-taking behaviour in the host species (rats & mice) – correlation – which may or may not improve the propagation of the parasite’s genes ?
In all these cases, particularly the given viral language of infections, it’s important not to fall into the trap of assuming the arrangement is necessarily bad for the host (individual or genes), just because it is good for the visitor’s genes. Parasites can be symbiotic.