In this thread, Monty offers a post which presupposes that a sequence of changes can not be both evolutionary and cyclic. I subsequently post a comment to the effect that my concept of evolution allows for the possibility of what we might call “cyclic evolution.” Monty disagrees–he says the phrase “cyclic evolution” doesn’t make sense.
My questions are these:
Do you think there can be such a thing as cyclic evolution?
My belief that there can be such a thing rests on my supposition that the term “evolution” is correctly applied (somewhat roughly speaking) to any sequence of changes undergone by some single entity. But am I right about that?
Anything from “IMHO” posts to “Here’s a definite knock-down cite for ya’” type posts are okay here.
What does “evolution” mean? In biology, it’s the change in allele frequencies over time, and there’s no reason why it can’t be cyclical if selection pressure are as well.
Well, there are such things as characters that revert–i.e., traits that were one way in an ancestor, are modified in a decendant, but then revert to the ancestral state again in the decendant’s decendant. Is that what you had in mind?
There are some pretty well-documented cases of this, actually. I’m too lazy to look them up right now, but I know they’re out there. The cases I know of have to do with critters staying one step ahead of parasites that infect them, and the parasite adapting to the changes in the host population, which causes another allele frequency shift in the host population, and on and on and on. You get the idea, I’m sure.
Couldn’t evolution favor genetic structures that lend themselves to change?
Suppose some little animal evolves on a small and isolated island, and this island tends to have climate shifts towards wetter versus drier climate ina 10,000 year cycle. The animal starts reproducing when it’s about 3 years old and stops by the time it’s 5, so generations are about 4 years apart, and there are 2500 generations during a cycle.
If the animal evolves in a long term sense so that genes that favor water use versus conservation are easily selected, maybe 2500 generations is time enough for short term evolution to keep the animal adapting back and forth in a pretty repeateable and cyclic manner.
To clarify, the question is not about biological evolution through natural selection as such, but rather, about the concept of “evolution” in general.
I do think there could be cyclical biological evolution through natural selection, and this would count as cyclical evolution in the more general sense as well. But my thinking this is possible is based on my thinking there is nothing conceptually wrong with the notion of cyclic evolution in the first place. The latter is the intuition I am trying to check on here.
It looks like people who have responded think, like me, that there’s nothing about the concept “evolution” which excludes the possibility of a cyclic evolution. Is there anyone who hasn’t responded, though, who, like Monty, thinks otherwise?
Are you suggesting that the DNA of a species may change between different “limits” over time, regardless of natural selection? Or that DNA can rewrite itself a little bit each generation, and somehow “loop around” afer x generations back to the original form?
I’m not certain I inderstand your meaning, but if I do, then no, you’re wrong I believe. But before I start arguing why, tell me if I am interpreting you correctly.
As I said in a later post, I’m not talking about biological evolution per se. I’m just asking whether the concept “evolution” precludes the possibility of an evolution that is cyclic.
But now that you mention it, I don’t see why it couldn’t happen that a series of mutations causes a descendant to be genetically closer to some of its more distant ancestors than it is to some of its more recent ancestors. This is certainly very unlikely to happen, but I can’t see why it would be impossible.
Ah, okay, you might be talking about the evolution of a society then, or an industry or business? Or the whole freakin universe?
That needs some thought, but my initial one is still that a “cyclic evolution” is doomed to failure over the mid to long term. I think anything that evolves does so within a larger context, and the evolution is necessarily influenced by that context. Sooner or later the context will change in a way that will will not fit between previously understood extremes. If the organism evolves through some other mechanism, it would inevitably result in something non-sustainable in the given environment.
OTOH there’s the economy, which operates in SOME kind of cycles that very few seem to be any good at inderstanding, and even the few not perfectly or not for long. Maybe the economy is some kind of meta-object, like a universe it self. It may or may not evolve itself, but it is vessal within which evolution takes place?
I thought Monty’s original comment was odd, because he seemed to think it can’t be “evolution” because languages aren’t becoming more complex or more “evolved” in the colloquial sense of the word. I don’t think biological evolution meets those criteria for “evolution” either - I think he was making the common mistake of thinking of evolution in terms of climbing up some ladder to some “higher state”. But that’s not accurate; there’s no meaningful way in which you can say that, for instance, bacteria are less “highly evolved” than humans. Likewise, while one can’t say that French is “more evolved” than Latin, it certainly evolved from Latin. Your use of the term “evolved” seemed pretty unexceptional; I’m certainly used to seeing language evolution described as “evolution” in academic text.
And if evolution happens to create some cyclical process, isn’t that “cyclical evolution”? It all makes perfect sense to me.
No, that’s not it at all. Evolution need not include “climbing a ladder.” It does, though, entail a different species developing. With language, that’s not the case at all. All the changes and it’s still language.
So there seem to be two separate questions involved in the conversation:
A. Can there be a cyclic evolution?
B. Do languages evolve?
Monty, it looks like for you the two questions are related. You think languages don’t evolve, for at least two reasons, and one of those reasons is, languages change cyclically, and you do not think there can be cyclic evolution. Meanwhile, the other reason is, language remains language even as it changes, but if it were evolving, then it should change into something that is not a language.
Regarding the second point, it seems like you we should say, using your form of argument, that species do not evolve, because no matter how much change there is from one point in a genetic line’s history to another, you’ve still just got species. Species remain species, so they do not evolve.
The obvious counter to that invalid argument is to point out that species do not remain the same species as you trace a process of speciation. That there is such a process constitutes the phenomenon of biological evolution.
Similarly, the obvious counter to your point about languages is to point out that languages do not remain the same language as you trace a process of linguistic “speciation” (so to speak). That there is such a process constitutes the phenomenon of linguistic evolution.
So your second point, that languages don’t evolve since all you ever have is languages after any process of linguistic change, doesn’t seem to work.
Your first point, that languages don’t evolve because languages change cyclicly, relies, as I noted, on a supposition that evolution can not be cyclical. That’s what I’ve started this thread to discuss. I haven’t seen, yet, any good reason to think that evolution could not be cyclical. Can you clarify why you think it’s impossible?
No it doesn’t. I posted the definition of biological evolution in post #2, and that certainly covers cases where no speciation occurs. I think you’re right, though, that languages don’t have selection pressures in the Darwinian sense, but that’s not to say that they don’t evolve. Linguistic evolution is probably most analogous to genetic drift.
This is correct, and it’s something I was meaning to address in a further post. Certainly languages are influenced to some degree by the social milieu in which they’re spoken - languages obviously won’t develop words for concepts that don’t exist in their culture (though, Boyo Jim, you should know that the idea that Eskimos have a large number of words for snow is an old myth.) But the primary mechanism for language change is just . . . well, languages change. Genetic drift is the closest biological model that applies, for the most part - changes resulting strictly from changes in social circumstances tend to be relatively minor, except in the (not quite comparable) situation of massive borrowing from other languages resulting from language contact. It’s not as though, for instance, something inherent about Finnish culture resulted in the need for a large number of noun cases, nor is there some selective pressure that caused many East Asian languages to develop tones. It’s certainly true that natural selection is not a useful model for language change.
However, I should point out that the concept of evolution exists apart from the concept of natural selection. Evolutionary models were proposed prior to Darwin’s work; the evidence for evolution had been mounting before the development of any good understanding of why it happened. Evolution, in the more technical definition of change over time, is certainly as good a descriptor as any for what languages do. (Though the specifically biological concept of allele frequency obviously isn’t relevant to language change.)
Evidently language isn’t the be all and end all it should be. Otherwise, my posts wouldn’t be so misinterprete here. Let’s try this again.
It 's not only for me, but for quite a few (purt near all competent) linguists, languages are not evolving. There is no appreciable difference in complexity or use in the different languages of the world. That is not to say that there are not differences in languages, but rather that language manifests itself regularly and similarly across all languages–i.e. no counterpart to allele change.
Oh, and before I forget, I’m not talking about the non-specialist’s usage of the term “language evolution.”
