Saturday 18 August 2012

Memes in the driving seat

It is widely believed that cultural evolution goes much faster than the evolution of human DNA can manage.

In my book on memetics, I discuss the "upright gait hypothesis" and the hypothesis that much speciation in the hominid lineage was assisted by memes.

Looking at the changes memes have produced in us, I think it is reasonable to propose the following bold hypothesis:

Practically all the significant differences between chimpanzees and modern humans are the consequences of human cumulative cultural evolution.

We can see the normal rate of morphological and behavioural change in primate lineages - by looking at our nearest relatives. Human evolution has been like a rocket by comparison - and memes explain why.

Much modern evolution is cultural evolution - memes explain all the interesting evolutionary change, while genes plod along at a glacial rate which is hardly noticable.

Coevolution between memes and genes mostly takes the form of memes dragging genes around in the adaptive landscape. The memes lead, while the genes follow. Genetic evolution is thus the delayed consequence of cultural evolution. The practice of drinking milk led to lactase genes being active an adults; the practice of talking led to larynx changes, and the practice of walking upright led to modified knees and ankles - and so on.

This idea also explains why our brains swelled up and why humans are ultrasocial.

It is an old idea in memetics. For example, Susan Blackmore (1999 p.80) raps on the Lumsden-Wilson "leash" metaphor - of memes being held on a leash by genes - saying:

In this way the memes are, as it were, dragging the genes along. The leash has been reversed and, to mix metaphors, the dog is in the driving seat.

The hypothesis here is the polar opposite of the position of Coyne 1999 who wrote:

Similarly, the self replication of memes does not mould our biology and culture; rather, our biology and culture determine which memes are created and spread.

Of course memes and genes coevolve, but the point is that the memes lead, and the genes are dragged along in their wake. This is an example of large organisms using small symbiotes to adapt quickly.

Since this "memes-lead" hypothesis explains so much of human evolution so well, I think the challenge is to look for puzzle pieces which it doesn't explain. I've looked, and haven't found very much - thus the bold hypothesis above.

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