Andrew,

You said, "We observe something and we come up with a theory that would explain the phenomon. Then we test the theory as best we can, particularly seeking to see if it holds predictive power."

When I was taught the scientific method, the first step was to create an hypothesis. Then the hypothesis is tested. If the tests show results consistent with the hypothesis, it becomes a theory. (i.e. it has, at least within the scope of the tests, been proven--it has predictive power)

In recent years the words hypothesis and theory have become synonyms. I have noticed this even from scientists, who should know better. This is unfortunate as makes things more confusing than they need to be.

I don't think that this is semantic quibbling. Hypothesis and theory are quite different things.

When someone says that "That's only a theory" I think that often they really mean that it's only an unproven idea, which, of course is not what theory means. They are either ignorant or are being disingenuous. Sometimes it's hard to tell.

In any case, I think that the rest of your article is well taken.

Dale Borgeson
dalebor@yahoo.com

I have trouble believing that the human race was formed in an accident or by chance.When I look at the people and the environment I see something that was created by some type of intelligent form.The complexity of the human mind,body and soul along with the perfectness of our atmosphere that enables us to survive doesn't seem like it happened without someone or something guiding it.I'm not a religious person but I do believe in creation over the blob in the puddle of mud theory at this point.

Dale,

Thanks for the clarification on the scientific method. As is probably obvious, I am no scientist, but I do have a great deal of respect for the scientific method. And it is certainly not my intent to disparage evolution as 'only' a theory, as my understanding of science leavened with your note suggests to me that a theory is one of the highest forms of knowledge: a hypothesis that stands up to testing. It is not necessarily perfect, as I noted above, but it is a methodical attempt to understand a natural process. I just wish that schools would do a better job of teaching the scientific method, as I believe greater literacy in it would go a long ways towards improving our educational system.

. . . has someone been able to demonstrate evolution in a lab? I'm completely serious on this; I'm not aware of any experiments that have been able to demonstrate evolution in action.

Hi Mr. Olmsted - evolution is both a fact and a theory. Evolution is precisely defined as any change in the frequency of alleles within a gene pool from one generation to the next. The gene pool is the set of all genes in a species or population. This is the neontological (biological) definition.

The fact that alleles within a gene pool change in frequency from one generation to the next is undisputed.

However, there are various theories that attempt to explain the mechanisms by which this occurs.

So, clearly, evolution is both a fact and a theory. Calling it "just a theory" is wrong, and shows that the person using such language does not understand what evolution is and is not.

As to your question on whether or not evolution has been demonstrated in the lab, the origin of a new species by evolution has been observed, both in the laboratory and in the wild. See: Weinberg, J.R., V.R. Starczak, and D. Jorg, 1992, "Evidence for rapid speciation following a founder event in the laboratory." Evolution 46: 1214-1220.

Brent,

Thank you for the explanation. Correct if I'm wrong here, but aren't there significant differences between the fact of evolution and the theory of evolution? The fact of evolution has been observed as you describe above. But the theory of evolution involves more than this fact, does it not? The theory of evolution, at least as commonly understood, proposes that random changes in gene structure over time reinforced by natural selection resulted in the predominance of favorable characteristics. To use a popular example, giraffes have long necks (according to the theory of evolution) because their most successful ancestors over time were those who could browse from foliage higher than any other animal could reach. Over many generations, the pre-giraffes, if you will, who had slightly longer necks were more successful in passing on their genes than the others, eventually resulting in the giraffe as we know it today.

I think the problem we have here is that we're conflating the narrowly-defined fact of evolution with the broader theory of evolution. When I argue that the theory of evolution is, in fact, a theory, the statement is factually true. The problem comes in when people fail to understand that all of science is predicated on theory, from the theory of gravity to the theory of relativity. We know that gravity exists; just drop something heavy above your toe if you're a doubter. But the fact of gravity is separate from the theory of gravity, which attempts to explain the fact of gravity. Evolution, I would argue, comes under the same umbrella.

Perhaps I'm just slow, but I don't see why calling something a theory is taken as an insult. Theories are how science works, and the theory of evolution is widely accepted because it does an excellent job of explaining the facts on the ground. Conflating the fact of evolution with the theory of evolution only seems to obfuscate the question.

Also, thanks for the cite, although I suppose it's too much to hope that it's available on the web somewhere?

The "evolution is change in allele frequency over time" definition is precisely the one Cline is using, and that one is pretty indisputable, since we observe it over time.
If that were all the biology textbook in question taught, I'm sure neither I nor anyone else would have any problem with it. But the creation of new species does NOT necessarily follow from change in allele frequency over time. And THAT is what is legitimate to refer to as a theory.
Let me take the word "evolution" out of my claim and say this:
"It is a theory that all life as we know it on earth is directly descended from a (or many) single-celled organism many many years ago."
I would also make this claim:
"The idea that lizards evolved from fish, or men evolved from apes, is a theory and has not been proven."

Those have certainly not been proven. They are theories. One may present EVIDENCE one believes is in favor of those two hypotheses. But it's unclear to me how one could prove those things, as it would be necessary to do to prove that those are facts rather than theories.

Cline and others have asserted "evolution is a theory and a fact." That may be true for change in allele frequency, but the items I mention above have not been proven.

It simply isn't true that the factuality of "change in allele frequency over time" necessarily means that we've all evolved from a fish.

I also want to mention that Cline seems unwilling to admit that the term "evolution" is ever used in biology in any other context aside from "change in allele frequency over time."

I do research in biophysics at a major university. In a research context, I far more often hear evolution used to say something like, "We can see how this is an evolutionarily conserved domain in this protein over many different species," which really means that (a) that particular protein is very similar in many different species, and (b) those species evolved from one another. And this is a very different claim from "change in allele frequency over time".

Honestly, I think proponents of evolution like the "change in allele frequency over time" definition because they can say, "Look, everyone agrees that this really happens! Therefore evolution is right." The problem is, that's NOT what anyone is objecting to. They're objecting to the OTHER use of the term, like what I mentioned above.

I'm fine if people want to try and shoot down my arguments. But I'd prefer if they would take the time to understand what I (and Andrew, in this case) am really saying, not shoot down something I don't actually think (i.e. that change in allele frequency over time is just a theory).

Hi Andrew,

Actually, there is not a single theory of evolution. There are upwards of twenty or more different theories that attempt to explain the mechanisms by which evolution occurs. The giraffe example you describe in your comment would seem to fall within the classic Darwinian theory of evolution called "Descent with modification". However, Darwinian theory is not the only one out there.

While the statement "evolution is just a theory" is technically true, it conveys the wrong meaning. Popular and colloquial meaning of the word "theory" distorts this statement until it seems to mean something that it does not. Consider again the Georgia sticker text:

"This textbook contains material on evolution. Evolution is a theory, not a fact, regarding the origin of living things. This material should be approached with an open mind, studied carefully and critically considered."

Here's the problems as I see them:

1. The sticker makes a statement that evolution is "not a fact." This is incorrect.
2. It mentions "theory' without explanation and allows for the popular and colloquial meaning to be used. The common usage of the word "theory" implies a shaky house-of-cards idea that is unstable. Kind of a wild-ass guess, if you will. The word "theory" in a scientific sense is "a coherent group of general propositions used as principles of explanation for a class of phenomena" [Random House American College Dictionary]. This does NOT imply a lack of certainty or a shaky foundation.
3. Evolution, both the fact and the various theories do NOT have anything at all to do with "the origin of living things." The area of scientific study that does in fact research "the origin of living things" is called "abiogenesis." Evolution concerns what happens to living things after they originated.

So, the majority of the disclaimer sticker is either completely false, or misleading. Calling something a "theory" is not an insult if you understand what the word means. It most definitely is an insult if the common usage implies that this "theory" thing is something that a bunch of godless biology majors dreamed up after a night of binge drinking and worshipping Satan. :)

I am afraid that I do not know where to find the cited journal article on the web. Sorry about that. I think that the Evolution journal will send you a reprint or a specific article, but their online archives only go back to Volume 54 from 2000, not back to Volume 46. (http://evol.allenpress.com/evolonline/?request=get-archive)

Brent,

Thanks for continuing the discussion.

As regards the sticker, if I haven't made that clear already, I believe that the ACLU is correct on the facts; it is inappropriate to single out evolution. All of science is based on theory, and theory has a very specific meaning that is at odds with the colloquial definition. As I've said in this post, I'd like to see more pressure on schools to teach the scientific method to improve general understanding on this, but that's a side issue.

Just as with the term 'theory,' 'evolution' carries certain connotations. I'll wager that the majority of Americans associate the term evolution with Darwinian evolution. And that meaning of the term is, in fact, a theory; it's just that it's a theory in the scientific sense of the term. But the term 'evolution is a theory' (I do object to the use of 'just,' because that's an inappropriate denigration of the term) is accurate if all sides are on the same page regarding the terms. But I agree with you that, given the common connotations of both terms, the stickers are inappropriate.

For my money, what we need is better teaching of scientific fundamentals and the scientific method in schools.

David,

You said:

Those have certainly not been proven. They are theories.
One may present EVIDENCE one believes is in favor of those two hypotheses. But it's unclear to me how one could prove those things, as it would be necessary to do to prove that those are facts rather than theories.

Cline and others have asserted "evolution is a theory and a fact." That may be true for change in allele frequency, but the items I mention above have not been proven.

Please allow me make one thing absolutely clear: Evolution has not, will not and cannot be proven. In this it is exactly like every other scientific discipline out there.

From The Evolution Fact FAQ by Dr. M.R. Liepzig:

There is a type of epistemological argument contra evolution.

Science maintains that nothing in science can ever be "proven" and this includes evolution. Semantics aside, "proof" and "proving" are not something done in science. As the old saying goes: "Proof is for alcohol and mathematics"; natural science deals not with proof, but rather evidence. This is another distinction of science.

Continuing, the probability that evolution is the correct explanation of life as we know it may approach 99.9999...9% but it will never be 100%.
Some would contend that this would lead to the conclusion that evolution cannot be a fact (see #1). This kind of argument might be appropriate in a philosophy class but it won't do in the real world. A "fact", as Stephen J. Gould pointed out (see above), means something that is so highly probable that it would be silly not to accept it. This point has also been made by others who contest the nit-picking epistemologists.

"The honest scientist, like the philosopher, will tell you that nothing whatever can be or has been proved with fully 100% certainty, not even that you or I exist, nor anyone except himself, since he might be dreaming the whole thing. Thus there is no sharp line between speculation, hypothesis, theory, principle, and fact, but only a difference along a sliding scale, in the degree of probability of the idea. When we say a thing is a fact, then, we only mean that its probability is an extremely high one: so high that we are not bothered by doubt about it and are ready to act accordingly.

"Now in this use of the term fact, the only proper one, evolution is a fact. For the evidence in favour of it is as voluminous, diverse, and convincing as in the case of any other well established fact of science concerning the existence of things that cannot be directly seen, such as atoms, neutrons, or solar gravitation ....

"So enormous, ramifying, and consistent has the evidence for evolution become that if anyone could now disprove it, I should have my conception of the orderliness of the universe so shaken as to lead me to doubt even my own existence. If you like, then, I will grant you that in an absolute sense evolution is not a fact, or rather, that it is no more a fact than that you are hearing or reading these words."

H. J. Muller, "One Hundred Years Without Darwin Are Enough" School Science and Mathematics 59, 304-305. (1959)

Andrew,
Just wanted to chime in on your final position, since I'm a creationist: "The creationists are made because I've ... come down on the side of the ACLU." I just wanted to let you know I'm not mad at all. I appreciate your ability to carry out a civil discussion on the whole matter. I was somewhat surprised to begin with you came down against the ACLU on this one, anyway.

I still do have a bit of a problem with how much respect people give a lot of theories, but that's maybe a topic for another post on my part. To shift away from evolution, though, I respect "big bang theory" pretty highly, as there's a lot of experimental evidence in its favor. On the other hand, I don't respect string theory nearly as much, as it's something which has almost no possiblity of being tested experimentally (at least, most of it) anytime in the forseeable future; it's largely based on the fact that if you make certain assumptions, lots of math works out very nicely and you end up deriving many of the laws of physics, so it's really based on math, not on experiment. Both are called theories; I would cheerfully call both "just a theory" -- since it's hard to do experiments which directly confirm either (i.e., no one can reproduce the big bang -- at least not so far). On the other hand, I would have a problem with anyone who calls Einstein's theory of special relativity "just a theory", since many scientists experimentally observe what the theory describes every day (and have to correct for the "relativistic effects" of the theory in order for their measurements or experiments to turn out right).

Maybe scientists should take to ranking their theories on some scale having to do with degree of certainty, as in the three examples I just cite, there are very different degrees of certainty.

I hope that all makes sense. Anyway, overall I just wanted to let you know you won't make me mad on this one just by disagreeing with me, since you've done it quite respectfully. And for that I thank you.

Oops, got my URL wrong on the last post. The correct one is above.

Wow! Lots of discussion, lots of ideas. I will just note in passing two things I have read on the subject of speciation. I'm not sure where I read it but it was several years ago that some biologist, passing through the Galapagos Islands at several different times years apart noted that a certain type of bird had small beaks during his first visit but had, over many years been replaced by birds with much larger beaks. he also noted that this may have been driven by a change in the food source on the specific island. Since the new food source was much harder to crack open, he hypothesized that birds with much larger beaks had been more successful in breeding and therefore had replaced the earlier birds with the smaller beaks, quantitatively. this seems to be a case where one could and did observe a slight change in species characteristics driven by an environmental change.

The other case was cited on the web about a week ago. Some scientists had been subjecting a group of fruit flies to harsh environmental changes over 27 generations and claim to have seen a change in speciation. Not sure where the citation was nor if their claim is accurate but they are working to demonstrate that evolution can and does still occur.

Anyone read Darwin's Radio by Greg Bear? If not, you should. It postulates the beginnings of the replacement of humanity by the next wave of homo ????. Entertaining book and very interesting from a sociological viewpoint.

Finally, one theory that has gained some acceptance from certain biologist is called punctuated equilibrium. Basically, the argument is that species types remain frozen over long periods of time and then some major event causes the death of many species opening up ecological niches for new species to evolve. Think asteroidal collisions.

Evolution is both a fact and a theory. One fact is that over time species change and another is common descent. Both are reasonably good inferred facts. Most people who object to evolution are objecting to the idea of common descent, especially in the case of descent of man from earlier primates.
Evolution is also sometimes called a theory and what it meant by this is how those changes come about. Even early naturalist stuck in the full blown clutches of a very theistic western Europe 200 years ago strongly suspected some kind of familiar relationship among diverse taxa. Darwin was the first to propose a mechanism which made sense, natural selection, and which explained how divserisifation/speciation from common ancestors might occur over time.

The version we use today is called The Modern Synthesis and incorporates additional data unknown in Darwin's time. The Modern Synthesis includes Punk Eq, drift, and so forth, as well as classical Darwinian Gradualism.

Brent, this statement is way out of date:
"Now in this use of the term fact, the only proper one, evolution is a fact. For the evidence in favour of it is as voluminous, diverse, and convincing as in the case of any other well established fact of science concerning the existence of things that cannot be directly seen, such as atoms, neutrons, or solar gravitation ...."
There has NEVER been demonstrated proof of macroevolution. And fruit flies, no matter how many generations of being subjected to harsh environments, are still fruit flies.