Susan Blackmore is a really interesting person. She thinks broadly about many things and her conversation is great fun. But her recent article in New Scientist is less fun and more handwaving, and the reason why is, I think, of the greatest importance to thinking about evolution… replicators.
Susan argues that not only are we, as Dawkins famously wrote, the hosts to a new replicator in memes, but that there is a third kind of replicator, self-replicating technological entities (for which she wants a name: how about simulemes? Send the cheque to my PayPal account).
I used to be a firm meme enthusiast – in fact my first papers were on that topic. However, I began to lose the faith, so to speak, as I reflected on the nature of cultural evolution. I still think my early papers (linked to above) had a lot of good material, but the core problem was that it seems to me that evolution does not require digital replicators, and indeed, culture had very few of them. Eventually, when reviewing Bob Aunger’s book The Electric Meme, I came to the conclusion that culture needs only the stock entities of social science: ideas, institutions, behaviors, practices and techniques. All of these evolve in culture, yes. But they aren’t replicators, nearly all the time. There is no code, no digital structure, and no conception like a locus, in genetics, where alternative genes compete under the neo-Darwinian conception.
And there is the hint – neo-Darwinian theory is a special case of evolution, not the general theory that all evolutionary processes must obey. In fact, we are finding more and more cases in biology where the neo-Darwinian account is either incomplete or fails. And this should come as no surprise, in hindsight. The theory was based on a restricted number of organisms (just like early molecular genetics was based on a restricted class of bacteria) that we needed to use in order to be able to make progress. Some assumptions, like the impossibility of lateral genetic transfer or hybridisation, were simply working assumptions, made later on into a form of dogma from textbooks, that needed to be expanded and qualified.
So when the Mendelian, Weismannian, Crick-and-Watsonian form of evolution was abstracted by Hamilton, Price, Williams and eventually Dawkins, it was, per necessity, a limited form of evolutionary theory that got so abstracted, and which captured the imagination of the non-biologists. Moreover, it wasn’t even all of that theory, but only a particular kind, sometimes called the panadaptationist view, that became “Darwinism”. It left out, for example, genetic drift as uninteresting, when it may be the single most significant “process” of evolution.
Now, I’ve railed against the use of the term “Darwinism” before, but the point here is that the notion of a replicator so beloved of Dawkins and those who followed him, is based on an abstraction from Mendelian genetics (hereditary factors) in terms of a “digital” molecular gene. G. C. Williams, who proposed the notion of an “evolutionary gene”, noted that it was a “cybernetic abstraction” in 1966, but this qualification was overlooked by the meme theorists who took information to be a causal power.
Dawkins’ definition of a replicator was directly taken from a generalised gene: it is information that is copied accurately in new physical substrata. Hence, if memes were replicators, they had to be hifi information with digital structure, and therein lay the problem. The sorts of things meme theorists used as examples were not, in any meaningful manner, digital. Sure, you could describe them with some digital formalisation, but they were nothing at all like genes. Dawkins’ own example: copying the wearing of a baseball cap backwards, is a case in point. How many degrees is “backwards” Just 180° or is there some slop?
When I once watch a fellow isolate some DNA (as part of a secondary school project I was assisting at the time), we came up with a test tube of smoky white goo. That was pure DNA. Did it replicate? It did not! It just sat there in the tube, slowly denaturing. DNA is a pretty inert sort of chemical. To do stuff, it needs an entire machinery. It needs a cell. It needs also an environment. And it needs a developmental process – cells do not use DNA all at once and all the same way. Organisms have life stages, and DNA plays a part in what the organisms do at each stage. DNA molecules are neither sufficient, nor the only necessary elements of living evolving systems.
So memes, whatever they may be, by analogy are not digital “messages”. They are part of a developmental system, and involve all kinds of machinery needed to make them get copied. But is what gets copied digital? No, it isn’t. In cultural evolution, at any rate, there are no viable candidates for digital information, despite our rather recent inventions of written language and digital computers even more recently. What gets copied are ecological functions. In biology, there is something that permits the longstanding transmission of functions rather well; DNA (and RNA in some viruses). But the functions do not map nicely onto the DNA because DNA is just one part of the machine. It’s like saying that sprockets are what make Formula One engines work. Sure they do, but in different ways in each engine. What counts in evolution, and in Formula One races, is the functioning of the entire system.
So we need the entire system to reproduce to have evolution (and one way to achieve that is to have digital replicators, but not the only way and not alone). Jim Griesemer has a notion: reproducers. A reproducer is something that is material (which is to say, it can cause things and be caused) not abstract, and which is contiguous with its parents. [Griesemer has them with a “material overlap”, but this is a case of overly specific exemplars taken from, in this case, cells in biology. So long as there is a causal connection, like templating, there is a reproducer in my opinion, also the view of Peter Godfrey Smith in his recent book.]
The thing about reproducers is that the relations from parent to child are relations of similarity; a parent resembles its child more than the child resembles a non-parent, overall, because they are generated. Really, so long as there is some way that the parent-child lineage is caused to reproduce functions and traits, you get your evolution.
Culture evolves because it has reproducers. And no reproducer is, as Donne might have said if he were a technbiogeek of the 21st century, entire of itself. It needs an ecology (how many mammals in a hard vacuum reproduce?), it needs other members of its population nearly all the time, and it needs a developmental cycle. In fact, a reproducer is a developmental cycle.
What does this do for the meme theory? It means that we can stop obsessing over informational, digital, models of heredity and start to think about developing systems. The “third replicator” turns out, if it exists, to be a case in which populations of things that develop and reproduce are able to evolve. Cultural items evolve because we are their reproducers, most of the time. But if humans are taken out of the process, it remains a cultural evolution process in one way. It might in fact be better to say, evolution happens on a variety of substrates. But we knew that already – viruses, bacteria, fungi, algae, lichens, birds, bats and beech trees all have distinct physical substrata and environments. This means the “new” reproducer is one of many new reproducers that evolve every time there is a new, well, taxon of reproducers.
We like to think that humans represent some kind of great innovation in the history of life, and hence anything that evolves from humans is also a great innovation. But really, every species represents a new way in which physical objects can evolve; that’s pretty much what “species” means, a type of thing that is special. The temptation to make us the acme of history is hard to resist, but if we do not want to merely repeat comfortable clichés to each other and actually learn about the world, we had better resist it. Personally, I think the acme of evolution is the corvid group of birds.
If we make reproducers, then they will evolve too. And they will be novel. As is everything else…