Sunday, August 22, 2010

Replicators & Genes & Memes & Temes

Susan Blakemore has written a post on the NY Times Opinionator blog that presents her latest thinking on memes:
I want to make three arguments here.

The first is that humans are unique because they are so good at imitation. When our ancestors began to imitate they let loose a new evolutionary process based not on genes but on a second replicator, memes. Genes and memes then coevolved, transforming us into better and better meme machines.

The second is that one kind of copying can piggy-back on another: that is, one replicator (the information that is copied) can build on the products (vehicles or interactors) of another. This multilayered evolution has produced the amazing complexity of design we see all around us.

The third is that now, in the early 21st century, we are seeing the emergence of a third replicator. I call these temes (short for technological memes, though I have considered other names). They are digital information stored, copied, varied and selected by machines. We humans like to think we are the designers, creators and controllers of this newly emerging world but really we are stepping stones from one replicator to the next.

...

First there were genes. Perhaps we should not call genes the first replicator because there may have been precursors worthy of that name and possibly RNA-like replicators before the evolution of DNA (Maynard Smith and Szathmary 1995). However, Dawkins (1976), who coined the term “replicator,” refers to genes this way and I shall do the same.

We should note here an important distinction for living things based on DNA, that the genes are the replicators while the animals and plants themselves are vehicles, interactors, or phenotypes: ephemeral creatures constructed with the aid of genetic information coded in tiny strands of DNA packaged safely inside them. Whether single-celled bacteria, great oak trees, or dogs and cats, in the gene-centered view of evolution they are all gene machines or Dawkins’s “lumbering robots.” The important point here is that the genetic information is faithfully copied down the generations, while the vehicles or interactors live and die without actually being copied. Put another way, this system copies the instructions for making a product rather than the product itself, a process that has many advantages (Blackmore 1999, 2001). This interesting distinction becomes important when we move on to higher replicators.

So what happened next? Earth might have remained a one-replicator planet but it did not. One of these gene machines, a social and bipedal ape, began to imitate. ... Whatever the reason, our ancestors began to copy sounds, skills and habits from one to another. They passed on lighting fires, making stone tools, wearing clothes, decorating their bodies and all sorts of skills to do with living together as hunters and gatherers. The critical point here is, of course, that they copied these sounds, skills and habits, and this, I suggest, is what makes humans unique. No other species (as far as we know) can do this. Song birds can copy some sounds, some of the other great apes can imitate some actions, and most notably whales and dolphins can imitate, but none is capable of the widespread, generalized imitation that comes so easily to us. Imitation is not just some new minor ability. It changes everything. It enables a new kind of evolution.

...

A sticking point concerns the equivalent of the meme-phenotype or vehicle. This has plagued memetics ever since its beginning: some arguing that memes must be inside human heads while words, technologies and all the rest are their phenotypes, or “phemotypes”; others arguing the opposite. I disagree with both (Blackmore 1999, 2001). By definition, whatever is copied is the meme and I suggest that, until very recently, there was no meme-phemotype distinction because memes were so new and so poorly replicated that they had not yet constructed stable vehicles. Now they have.

Think about songs, recipes, ways of building houses or clothes fashions. These can be copied and stored by voice, by gesture, in brains, or on paper with no clear replicator/vehicle distinction. But now consider a car factory or a printing press. Thousands of near-identical copies of cars, books, or newspapers are churned out. Those actual cars or books are not copied again but they compete for our attention and if they prove popular then more copies are made from the same template. This is much more like a replicator-vehicle system. It is “copy the instructions” not “copy the product.”

Of course cars and books are passive lumps of metal, paper and ink. They cannot copy, let alone vary and select information themselves. So could any of our modern meme products take the step our hominid ancestors did long ago and begin a new kind of copying? Yes. They could and they are. Our computers, all linked up through the Internet, are beginning to carry out all three of the critical processes required for a new evolutionary process to take off.

...

This is a radically new kind of copying, varying and selecting, and means that a new evolutionary process is starting up. This copying is quite different from the way cells copy strands of DNA or humans copy memes. The information itself is also different, consisting of highly stable digital information stored and processed by machines rather than living cells. This, I submit, signals the emergence of temes and teme machines, the third replicator.

What should we expect of this dramatic step? It might make as much difference as the advent of human imitation did. Just as human meme machines spread over the planet, using up its resources and altering its ecosystems to suit their own needs, so the new teme machines will do the same, only faster. Indeed we might see our current ecological troubles not as primarily our fault, but as the inevitable consequence of earth’s transition to being a three-replicator planet. We willingly provide ever more energy to power the Internet, and there is enormous scope for teme machines to grow, evolve and create ever more extraordinary digital worlds, some aided by humans and others independent of them. We are still needed, not least to run the power stations, but as the temes proliferate, using ever more energy and resources, our own role becomes ever less significant, even though we set the whole new evolutionary process in motion in the first place.
I find her proposal to be somewhat murky. But this is what I get out of it:
  • The original replicator might have been RNA-based life or some other form. But this replicator has vanished in favour of the current dominant replicator: genes.

  • Genes replicate using the phenotype of the physical body (cell, plant, or animal). The body is like a blind robot whose job is to deliver the next version of the gene into the future. The gene is the replicator, but the body is the replicator factory.

  • Memes arose because humans can imitate. Once you get imitation going then you have the basis for evolution (copying, variation, and selection among variants). I find Blakemore fuzzy on what the phenotype of a meme is. At times it seems that a human, at other times, the culture, but then she seems to be saying that it is factories that produce instantiations of ideas (cars, products, etc. that vary over time and be selected by humans thereby deciding which memes live or die).

  • A third replicator -- temes -- are new on the scene. The temes are information generated by networked computers and spread. These temes can create copies and variations. It isn't clear what the selection mechanism is, so the engine of evolution is unclear. It is also unclear to me what the "phenotype" is. It would appear that some software program inside the networked computers is the body that generates the temes. It appears that she suggests that Google searches are an early "teme".
This is suggestive and interesting, but it is pretty murky. I would need to read more and a clearer presentation before I would be convinced. I accept the idea of memes. To me the phenotype of a meme is a collective human activity (like culture, or even a group) that preserves, copies, varies, and selects memes. The stuff about "temes" is too speculative and sketchy for my taste.

You can follow up on Susan Blackmore at her web site.

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