As a professor of biology who teaches in a science-focused university, I have found it instructive to use the analogy of Darwinian evolution (which my students in general know) to inform a discussion of folk process (which in general is a foreign concept to them). What I learned from my initial post here is that within the folk music community, understanding of the theory of evolution is so uneven that the analogy only causes confusion, at best.

However, as this thread continues, I feel obligated to clear up a very common but extremely mistaken view that seems to be persisting here. In Biology "evolution" does not in any way imply "improvement" nor progression towards any higher form. That is simply not part of the theory as presently understood.

For those who care to know what the basic theory actually is, I will give a brief and necessarily incomplete summary. It's really a simple logical inference. But to make all the points necessary to usefully compare AND CONTRAST folk process to biological evolution would require several lectures, which is too much to type here.

Proposition 1: Variation. Members of a species are not all identical.

Proposition 2: Heredity. Some of the characteristics that vary among individuals are heritable - obtained as some kind of "copy" from one or more previous copy, which we call its parent(s). Therefore an individual's trait is more likely to resemble its parents and also its closely related relatives (siblings, cousins, etc) than it resembles a randomly selected individual of the same species.

Proposition 3: Selection. Some of the characteristics that vary among individuals have consequences for the chance of the individual surviving long enough to leave behind copies (offspring), or affects the number of copies made, or chance of those copies surviving.

Logical inference: IF a trait varies, AND is heritable, AND has a consequence for the chance of survival, then those variants which increase the probability of survival will by definition tend to be more numerous in the next generation. Because this iterates, the population composition tends to change gradually over time.

That's the essence of it.

Some things to note:

"Evolution" only means "gradual change" - in any direction good or bad, by any process.

"Evolution by natural selection" means gradual change in the composition of a population due to the factors mentioned above.

The variants that increase in representation are not necessarily more complex or "better" in any way; they are merely the ones that increase in representation. Value judgments are a human construction that have nothing to do with this.

Evolution does not tend toward perfection and there is no top to any pyramid, no such thing as a higher life form. From bacteria to fruit flies to humans, everything surviving on earth today has evolved to an equal extent. Arguably the flies have evolved more, and bacteria the most, because they have had so many more generations than mammals.

So *to the extent that*
~not all versions of a folk song are identical (variation)
~one person's version is obtained as a copy of one or more previous versions (heredity)
~some versions have attributes that make them more likely to be sung or copied by others (selection)

It follows by analogous arguments that some versions in generation N will be more prevalent in generation N+1. Not necessarily *better* versions. But the influence of selection could help explain why prevalent versions share certain characteristics.

Of course that's not the really interesting part of the conversation. Many other issues that come up in folk process have also been intelligently grappled with by biologists -- are mutations random events, or are they directed toward a goal, and how can we know that? How do we assess this process when we have limited or no access to what the earlier variants were? what about traits that are not heritable, or that have no survival advantage? why does one variant sometimes take over completely? why are different variants found in different locations? what about the fact that the conditions for survival keep changing over time? how do some lines go extinct? how do new ones come into existence? How does "unnatural" selection (criteria imposed by human intervention) relate to, and interact with, natural selection?

The answers to these questions may be the same or different for folk process vs. biology, indeed the answers are different for different biological examples, and probably different for different folklore examples. The point of drawing on analogy is it allows us to leverage human learning - in both directions. Great ideas are hard to come by and it's likely each discipline has insights the other hasn't discovered yet. The transfer of knowledge doesn't come free, however. One must first truly understand an idea within its own field, and then critically evaluate whether or not and in what specific ways it applies to another field.