Monday 11 March 2013

Massimo on cultural evolution

Massimo Pigliucci is one of the few remaining critics of memetics who still pops their head up now and again.

In his latest broadside, he provides a neat summary image ->

Firstly culture is biological. It is part of biology which is the study of life. Culture is part of that - as opposed to being inorganic, like most geology. Contrasting "Cultural evolution" and "Biological evolution" is only possible if you don't grasp this.

From the bottom up:

  • Organic evolution does exhibit horizontal and oblique transmission. These terms are standard in epidemiology, and come from the organic realm, not the cultural realm. Cultural evolution students borrowed these terms from epidemiology in the 1980s. Horizontal transmission is the norm in bacteria - which represent most of the individuals and species on the planet. The idea that organic evolution does not exhibit horizontal and oblique transmission is completely wrong. Nor are horizontal and oblique transmission at all rare.

  • Massimo claims organic evolution is "non-intelligent". Yet there is selection by intelligent agents in the organic realm all the time. Large-brained organisms choose who to have babies with, when to fight, and when to run. The idea that organic evolution is "non-intelligent" is completely wrong.

  • Lastly, there's variation. Massimo claims that "a cardinal tenet of the Modern Synthesis (and indeed of the original Darwinism) is that mutations — the ultimate source of novelty in evolution — are random with respect to fitness outcomes". Of course, most mutations are deleterious. However after trying for a sympathetic reading, the claim that mutations are "random" with respect to fitness is outdated neo-Darwinian dogma. Organic mutations prefer junk DNA to coding regions. They also prefer recently-mutated regions. Both patterns bias mutations in the direction of being less maladaptive than "random" mutations would be. Selection acts on mutation rates in many ways - controlling its rate on a species-by-species basis - and a tissue-by-tissue basis. SINEs and SINEs also cause mutations in ways that are strongly subject to selection. Mutation just isn't a phenomenon which is random w.r.t. fitness.

I make that zero out of three. Not a good showing. Only the point about variation remains at all controversial.

Massimo says:

This is the section in which he cites the now classic work of people like Cavalli-Sforza, Feldman and others on gene-culture co-evolution. The thing is, if we are meant to take that (interesting, pioneering) work as a way to theorize about cultural evolution, we are at a dead end. Most of those papers are from the 1970s and ‘80s, with very little having been done since. That approach looks increasingly like what philosopher of science Imre Lakatos famously called a “degenerative” research program, i.e. an approach that seemed once fruitful but that has since ceased to bear fruits.
Unlike Massimo, I am familiar with much of this literature, and my testimony is that he is wrong about this. I've previously graphed papers on memetics.

I checked with Google scholar on "cultural evolution". It shows this growth:

1970s: 27,400
1980s: 79,800
1990s: 372,000
2000s: 1,150,000

Of course most scientific fields are growing, but the field of cultural evolution is exploding - and, yes, some of those papers are doing meme frequency analysis based on population genetics.

In the comments, Massimo repeats one of his more ridiculous objections to cultural evolution:

No, there is a huge difference: what saves the theory of natural selection from being tautological is the existence of a functional ecology of living organisms: we can predict which characteristics of an organism, given a certain environment, are more or less likely to be selected. No such thing is available for memetics. In the latter case all there is to it truly is: the fittest memes survive. Which memes survive? The fittest ones!
Nobody in the field takes this kind of nonsense seriously. I previously destroyed this objection here.

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