I’m reading Humberto Maturana and Francisco Varela’s The Tree of Knowledge. The authors are setting up their own theory of knowledge, based on the idea of autopoeisis and various ideas about constructivism. A lot of their theory seems based on something they call “natural drift” (bear with me – it’s the German edition I’m reading, that may not be what they call it in English). In an inset, they set this off against evolution-as-selection, apparently, by denying any “advance” in autopoetical existences, but an aimless movement in which an autopoetical being and its surroundings drift from structure to structure.
I’m probably not doing this much justice, so please help me out, if you can:
Am I remotely close in my explanation of drift? Is the only thing Maturana / Varela take exception to the idea of an “advancement” in species through selection (something I think at least neo-Darwinism would agree does not happen – in the teleological sense of advancement towards a goal).
What’s the current opinion on natural drift as an alternative to natural selection.
If I’m parsing your question rightly, natural genetic drift isn’t an alternative to natural selection. It’s just another force that exists in the shaping of genomes. It refers to variation occurring randomly and spreading through the population not because it provides a benefit but just through random happenstance. For obvious reasons, this is more likely to happen in very small populations.
It’s just something that happens and exists. Ain’t no big thing.
I’m not sure that’s what they want to say. As far as I could tell from the book, Maturana and Varela (who NEVER use selection as a term, or acknowledge the idea of “benefits” to an organism) do indeed intend drift to replace the idea of selection. I’m willing to be dissuaded from this reading of their book, however…
I don’t know anything about autopoesis, or constructivism, or really epistimology at all.
But for question 2, here’s the answer:
Natural drift does indeed happen (a biologist would probably call it “Genetic Drift” in English), but it’s effect is very small compared to natural selection.
(There is a slight exception: it’s possible to make small changes in a gene that don’t actually end up making any difference in the final organism; for these kinds of changes, genetic drift happens commonly. But in this case there’s zero bottom-line effect from the drift).
For question 1: I’m not entirely sure what Maturana/Varela are saying, but to better characterize the neo-Darwanist perspective, I’d say that the key point is that natural selection does not advance towards a steady consciously-chosen goal, but it is always advancing (as much as possible) towards a short-term goal of an organism with more descendents.