Evolution is Both a Fact and A Theory

| 66 Comments

When I was in grad school at the University of Georgia, I participated in a case concerning the teaching of evolution: Selman v. Cobb County School District. The case revolved around a disclaimer that the affluent Cobb Country (Georgia) School Board affixed to biology textbooks.

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.

And for those of you who don’t remember, the county lost:

The critical language of the Sticker that supports the conclusion that the Sticker runs afoul of the Establishment Clause is the statement that “[e]volution is a theory, not a fact, concerning the origin of living things.” This statement is not problematic because of its truth or falsity, although testimony from various witnesses at trial and the amicus brief submitted by the Colorado Citizens for Science, et al. [That’s us!], suggest that the statement is not entirely accurate. Rather, the first problem with this language is that there has been a lengthy debate between advocates of evolution and proponents of religious theories of origin specifically concerning whether evolution should be taught as a fact or as a theory, and the School Board appears to have sided with the proponents of religious theories of origin in violation of the Establishment Clause.

As you can see, an important part of the case hinged on the misleading language of the disclaimer. (The state of Alabama is still slapping similar disclaimers on books.) So it is great to see that Larry Moran has updated his article, “Evolution Is a Fact and a Theory” and posted it on his blog. Of course, it’s unfortunate that we still have to make this point because some people never get it.

66 Comments

I think it’s fair to say creationists deny the FACT of evolution, therefore the mechanisms of course cannot cause what does not happen. The rest of their arguments are ways to misrepresent the mechanisms accordingly - and in the process, misrepresent research into those mechanisms, misrepresent what the researcher say, etc.

When they say evolution is a theory and not a fact, what they mean is that the actual changes over time are “theoretical” (that is, atheist guesses and lies), because what is discovered can’t be evidence, because the “fact of evolution”, not being true, can’t HAVE evidence.

And it’s always good to recall Ken Miller’s thoughts on those warning labels.

Living in Texas, I used to hear this argument all the time.

I used to reply that evolution was a theory… one hundred and fifty years ago when the idea was first named.

You know, before the civil war.

When the telegraph and steam engine were promising new technologies that might be useful one day.

Before time zones, in a day when, for all practical purposes to anybody other than sailors, the world was still flat.

30 years before the atom or photon were discovered.

Five decades before the Wright brothers.

And since then it’s been tested over and over and over and over again.

Tested by millions of scientists belonging to dozens of religions in a hundred countries for fifteen decades.

Tested and tested and tested and tested again and again and again.

It is regularly demonstrated in real time in graduate biology labs all over the planet - and it has been for a century.

And in all that time nobody has ever found a fatal flaw.

Of all those millions of people who have dealt directly with this stuff only a small handful - who make their money writing popular books about how wrong evolution is - make any claim at all that evolution is wrong. And yet none of them can actually demonstrate any actual evidence.

And they’ve had fifteen decades.

Now, why do you think that might be?

Here’s the bottom line;

Evolution was a theory - one hundred and fifty years ago when it was named.

But you test something for fifteen decades and it’s not a “theory” any more. It’s a fact.

This post left such a sour taste in my mouth I felt I had to comment - something which I very rarely do.

The intention of that disclaimer seek to make evolution appear less credible then it should, yes, but you’ve got your terminology completely wrong.

A theory is a system made to explain a set of phenomena. From a theory we can deduce testable statements, usually called ‘predictions’. Then we test these statements by comparing them to the results of experiments. If the predictions match up, then the theory has, for the moment, passed - it has been verified. Evolution has been verified many times. But this verification is not conclusive proof.

Scientific theories must make testable predictions and therefore there is always the chance they can be disproved or superseded.

When you say evolution is not a theory but a fact what you mean is that it is not a hypothesis but a theory with a large amount of support.

For more information, and a much better explanation of the deductive method of testing, I recommend Karl R. Popper’s The Logic of Scientific Discovery. A preview is available on Google Books. His explanation is on Pages 9 and 10. Page 9 is unavailable there but Page 10 contains most of what I said.

lemeza99 said:

When you say evolution is not a theory but a fact what you mean is that it is not a hypothesis but a theory with a large amount of support.

No. “Evolution is a fact” refers to actual observations, the extensive observations of heritable changes in biological populations over time. The well-verified “theory of evolution” is a framework to explain these observations.

I’ll preface my remarks by noting that I claim no expertise on this subject.

I don’t like this way of expressing the thought: “Evolution is both a fact and a theory.”

This is, to me, a mixed metaphor.

A metaphor, because evolution is a process, something that happens in the world of life. Evolution is the change of hereditable properties in populations of living things across generations. Also expressed as common descent with modification.

It is a fact that evolution always happens to populations of living things as we know them, and always has, and, undoubtedly, always will.

And there are theories which (1) explain features of the world of life which come about because evolution happens and (2) which explain how evolution happens. For example, there is the theory(2) which explains that random variations and natural selection result in evolution. (There are other theories(2) of evolution, such as the “neutral theory” and “lamarckism”. Some theories(2) about evolution are more accepted today than others.) And there is the theory(1) which explains the nested hierarchy of the tree of life as a result of common descent with modification. The expression “theory of evolution” means something different, depending upon whether the “of” is the objective genitive or the subjective genitive. (Sometimes people confuse the expression “theory of evolution” as an appositive genitive, meaning “evolution, the theory”. Although people don’t seem to have that same confusion when speaking of “the theory of the earth” or “the theory of antennas” or “the theory of flight”.)

It is a metaphor to say that evolution is a fact. And it is a different kind of metaphor to say that evolution is a theory. Thus it is mixing metaphors to say “evolution is a fact and a theory”.

I wouldn’t complain about someone saying “evolution is a fact” as being a way of saying “it is a fact that evolution happens”. We can’t forbid metaphors in our language.

I would have some reservations about someone saying “evolution is a theory” if they didn’t make it clear whether they meant a theory about evolution or a theory using concepts of evolution. But I agree that it would be pedantic to insist that everyone always makes this distinction.

lemeza99 said: When you say evolution is not a theory but a fact what you mean is that it is not a hypothesis but a theory with a large amount of support.

If you read Moran’s essay, and the Gould essay that preceded it, you will see that their point is that there are both facts and theories of evolution. Descent with modification is an empirically observed fact: observe parent, observe child, notice differences. (And the 20th century contribution: notice allele differences.) Likewise, it is a fact that the fossil record shows life on earth changing over time. Again, dig up old fossils, dig up new ones, notice species differences.

No credible expert disputes these. You have to go to YECs like Ken Ham and find people who throw out all of modern geology and radiometric dating before you find someone who disputes these things. They are direct empricial observations, not theoretical explanations for them.

There are also theories of evolution, i.e., why and how does the pattern of allele frequencies change in a population over generations? Is it natural selection? Sexual selection? Genetic drift? Something else? Maybe a bit of all of the above? Those are theory questions.

But arguments over theory questions do not change the facts of evolution, which are that allele frequencies are observed to change over generations just as surely as objects are observed to fall. And that these allele frequency changes are observed to lead to speciation events.

stevaroni said:

Here’s the bottom line;

Evolution was a theory - one hundred and fifty years ago when it was named.

But you test something for fifteen decades and it’s not a “theory” any more. It’s a fact.

It bears repeating that evolution is both a fact and a theory.

Evolution as fact refers to the observed differences and changes that occur, and have occurred in populations of organisms over various generations.

Evolution as theory refers to the numerous, numerous sets of repeatedly tested and repeatedly verified hypotheses that describe and explain the biomechanicss, results, causes, rates, frequencies and effects of the aforementioned differences and changes in populations from generation to generation.

SWT said: No. “Evolution is a fact” refers to actual observations, the extensive observations of heritable changes in biological populations over time. The well-verified “theory of evolution” is a framework to explain these observations.

eric said: -snip-

Sorry! I’m always picky about the differences hypotheses, theories and facts. I completely forgot that evolution can refer to a physical process as well the theory.

English is such a wonderful language - multiple meanings for the same words, and politicians are such lovely people - they chery pick, conflate, redefine the meanings of words etc. to suit thier own ends. That label is intentionally using the colloquial/vulgar definition of “theory” (something that many believe might be true, but remains unproven) where a discipline specific definition should be used (theory = organizing principle that is the basis of experiment/research)

the label doesn’t even decribe waht evolution IS acurately - on the lable itself “Evolution is a theory, not a fact, regarding the origin of living things” Evolution is NOT about the origin of living things, thats biogenesis, or where life “startrd”. Evolution is about how living things CHANGE over time.

so to summarize, a fact is a single verifiable observation or datum or a statement of fact may summarize multple other facts, for example:

(Fact) Living things evolve

Any inference that the meaning of the word “theory” in this context means anything other than a framework or priciple that EXPLAINS FACTS is political manipulation of Orwellian proportions

again to summarize: (Scientific Theory) Natural selection explains some of the differencial survival of organisms from generation to generation. The differencial survival of phenotypes leads to net change of a populations distribution of genotypes over time…

Newsspeak/doublespeak/political language (AKA bullshit) version of “theory”: “Evolution is only a theory, not fact”

Apparently the problem here is that for reasons that end up being perverse, we have chosen to use exactly the same word to describe both a coherent body of observed phenomena, and a proposed set of causes of those phenomena. These are different categories. No matter how extensive or consistent our observations become, they can never become their own explanations. And explanations, no matter how well tested, can never become the observations they are testing. Using the same word for two different KINDS of things makes equivocation on that word almost impossible to avoid.

So when someone rejects “evolution”, it’s hard to tell which of these two very different meanings is intended, especially if the person doing the rejecting fails to realize that there ARE two very different meanings. For clarity of discussion, it would help a lot to have two distinct terms, so we make the conceptual distinction as well as the rhetorical distinction.

And yes, Masked Panda is correct in pointing out that this situation is compounded by the different meanings of the word “theory”, with the common understanding amounting to “any idle speculation, however uninformed, that anyone can dream up.” So we’re battling against the application of the word “theory”, the distinction between the observations and their explanation, and the notion that a sufficiently well-attested explanation can BECOME the observations it is explaining.

I never pay too much attention to the “evolution is theory (or not)” arguments. They seem to be merely evasions of the actual bottom line: no matter what real or imagined weaknesses can be painted onto evolution, creationism is still 100% baloney – and THAT is absolutely NOT a theory and IS a fact.

Teaching baloney to school children is ALSO a fact. The creationist drive to make teaching baloney a national policy is also a fact. So is creationist opposition to science. The goal is to make it more difficult for them, knowing they will never stop trying.

Flint said: Teaching baloney to school children is ALSO a fact.

I get this feeling that you want to argue with me, but I can’t figure out why I would.

Got baloney? Make sandwiches! (That’s my theory, anyway.)

With reference to creationism, a less appetizing sandwich filler comes to mind – but we won’t go there.

mrg said:

Flint said: Teaching baloney to school children is ALSO a fact.

I get this feeling that you want to argue with me, but I can’t figure out why I would.

No, I have no argument with what you’ve said. If I have any argument with you at all, it’s with what comes across to me as airy dismissal of their policies because their doctrine is baloney. As has been pointed out here with thumping regularity, scientists have seen no sense in getting involved with the politics, since the content is nonsense. And ignoring political battles is a surefire way to lose them.

Flint said: No, I have no argument with what you’ve said.

Well, given the disinterest on this end, I guess that ends the discussion.

Henry J said:

Got baloney? Make sandwiches! (That’s my theory, anyway.)

Why stick with baloney when you can use salami?

apokryltaros said: Why stick with baloney when you can use salami?

What we usually get is word salad.

mrg said:

Flint said: No, I have no argument with what you’ve said.

Well, given the disinterest on this end, I guess that ends the discussion.

You and my wife would get along splendidly. Her approach, just like yours, is to say “I’ve delivered my opinion, that ends the discussion, now go away.”

Flint said: You and my wife would get along splendidly. Her approach, just like yours, is to say “I’ve delivered my opinion, that ends the discussion, now go away.”

A friend of mine – a liberal Mormon, quite the interesting sort – once commented on disputes with his wife that he had learned to choose his battles more carefully.

Though I’m not married, I’ve always kept that as a very good piece of advice.

Apparently the problem here is that for reasons that end up being perverse, we have chosen to use exactly the same word to describe both a coherent body of observed phenomena, and a proposed set of causes of those phenomena.

Actually, Larry Moran dealt with this, and pointed out that this is the rule, rather than an exception. See his examples; for one off the top of my head, relativity.

It is common for an observed phenomenon and the theory that explains it to have the same name.

Stevaroni said -

I used to reply that evolution was a theory… one hundred and fifty years ago when the idea was first named.

You know, before the civil war.

That is a very good point, except that you’re arguing (correctly) that evolution isn’t a hypothesis. It is the name of both a factually observed process and the theory that explains that process, though.

A theory is a strongly supported unifying idea that explains multiple factual observations.

Here are just a few individual factual observations that the theory of evolution explains:

1) Insecticide resistance develops in insect populations exposed to insecticide.

2) Antibiotic resistance in bacteria.

3) Fossil series in the fossil record, e.g. horse, hominid, whale, dinosaur/proto-bird, etc.

4) Parasitic worms lack some features that free-living related worms possess.

5) Cave fish have vestigial eyes.

6) Any rational system of organizing species by degree of relationship shows a nested hierarchy.

7) ERV sequences - theory of evolution helps explain both their existence and the fact that across species, they recapitulate the same nested hierarchies obtained via classification by morphologic/physiologic features or by use of other genetic markers.

This tiny list is very incomplete. I could go on and on all day.

What are the elements of the theory of evolution? The following are observed facts -

1) Modern cellular organisms and viruses have genomes that are sequences of nucleic acid, virtually always double stranded DNA except for some viruses.

2) During replication and sometimes not even during replication, nucleic acid strands undergo “mutation” - “daughter” strand is not an identical copy of “parent” strand. In addition, in eukaryotic lineages, DNA undergoes recombination when it replicates for the formation of gametes. The expected rates of these processes are quite well understood and are sufficient to account for the genetic diversity of the biosphere.

3) Some mutations impact on phenotype. Offspring are virtually always somewhat different from parent(s) in phenotype.

4) Some phenotypes encounter selection in some environments; that is to say, reproduce more or less effectively than other phenotypes in the population, for reasons related to their interaction with the environment (or in some cases, simply because the phenotype cannot develop or thrive in any conceivable environment).

5) Mutations and recombination events occur as random variables relative to human observers and stochastic analysis may sometimes model the spread of alleles in a given population even in the absence of strong selective pressure.

Why is there a theory of evolution? Because the second set of facts here provides strong explanatory power to help us understand the first set of facts above.

The theory of evolution is not “complete”. There is plenty of work on the details. But it is highly unlikely that any of the facts I have mentioned here will be refuted.

There is plenty of room for clarification and expansion, but evolution is both an easily observed fact and a strong theory that explains the observation.

mrg said:

Flint said: You and my wife would get along splendidly. Her approach, just like yours, is to say “I’ve delivered my opinion, that ends the discussion, now go away.”

A friend of mine – a liberal Mormon, quite the interesting sort – once commented on disputes with his wife that he had learned to choose his battles more carefully.

Though I’m not married, I’ve always kept that as a very good piece of advice.

Hard to know you will encounter a battle until it happens.

harold said: It is common for an observed phenomenon and the theory that explains it to have the same name.

Yes.

This is metonomy, the metaphorical use of a word to refer to something related to the literal referent of the word.

For example, we may use the expression “geology” of some area to refer to the features of interest to geology: mountains, valleys, etc. Literally speaking, a mountain range is not geology, but everybody recognizes the use of the metaphor. Geology is the study of things like mountain ranges. The metonomy in this case is referring to something (mountains) related to something else (geology) to which it is related (by being the study of it).

For example, a Frankenstein is a monster made by Dr. Frankenstein. Foggy Bottom is the US Department of State which has offices located in the area called “Foggy Bottom” (itself another metaphor).

Flint said: Hard to know you will encounter a battle until it happens.

True, but once it does there’s the practical consideration of whether it’s worth the bother to fight it or not. The answer, sometimes, is NO.

The disclaimer equivocates in two ways. First, it conflates the fact and the theory of evolution into one confusing bundle. Then it carefully applies the vernacular sense of “theory - someone else’s opinion - where the scientific sense of “theory” should be used. It embodies the popular model of a “scale of certainty” running downhill from fact to theory to hypothesis to guess.

THEN it instructs school children to do an informed analysis knowing they are equipped neither with the relevant knowledge, nor the analytical ability. And of course it singles out evolution despite this same condition (lack of relevant knowledge and ability) applying to every subject the student encounters.

Taken altogether, this disclaimer decodes as “Trust us, evolution is bunk.” And everyone knows it.

mrg said:

Flint said: Hard to know you will encounter a battle until it happens.

True, but once it does there’s the practical consideration of whether it’s worth the bother to fight it or not. The answer, sometimes, is NO.

Agreed. There are times, however, when a discussion is NOT a battle, or doesn’t need to be. The thrust of the thread is that creationists are trying to shove baloney down the throats of school children, and what can we do about it. Observing that it IS baloney is entirely correct, and not in any way in conflict with the desire to protect children from it. Can we imagine a creationist thinking “Gee, he’s right, it IS baloney, I guess I’ll stop pushing it.”

If the state is saying that evolution , the great conclusions on origins thereof, is a fact THEN the state is saying it has a opinion on the subject. Since evolution being true means the bible in origins is not true then the state has a opinion, enforcing it, that the bible and therefore religion is not true. As the article said all of this is tied up with the evolution/creation contention. So its impossible for the state to say evolution is true and not be saying other ideas that reject it are NOT true. So the state has a opinion on religion and so breaks the establishment clause surely. There’s that equation again.

Who indeeds decides if evolution is a fact of truth? Either the people or a small group of people who know better. If the former then its right to use the government for equity or whatever conclusion. If the latter then the people should not matter. If a small group then why not the old way of a religious leadership? Democracy or not?!

IBelieveInGod said:

Is Universal Common Descent a FACT???

Yes, via some of the same exact processes used in paternity suits when they do DNA tests. The only difference is the closeness of the relationship.

Do you deny the validity of paternity DNA tests? Do you accuse the courts of having invalid presuppositions? Why not?

Atheistoclast said:

I think we need to distinguish between evolution and origination.

Who’s “we” pale face? The only people I ever see on here conflating the two are the evolution deniers.

Henry J said:

Speciation in finches and fruit flies is hardly evidence that all living things are the result of descent with modification. That is a massive extrapolation.

That is one piece of evidence. Nobody expects the theory to have to be proven all over again from each piece of data - it’s the patterns across all the relevant data that are the reason for accepting a theory, not any one data point taken by itself.

Agreed, and I couldn’t have said it better myself, Henry J.

eric said:

Atheistoclast said: Speciation in finches and fruit flies is hardly evidence that all living things are the result of descent with modification. That is a massive extrapolation.

So, just so I get your position straight: you are hypothesizing an invisible, omnipotent, omniscent, benevolent diety magically poofing life forms into existence, because you dislike massive extrapolation?

He’s ashamed to admit that that deity is some entity named Lucifer. Or maybe it’s some obscure Klingon GOD I haven’t heard of before.

IBelieveInGod said:

Is Universal Common Descent a FACT???

YES, IBIG it is a fact.

That’s the name for something that you’ve tested for 150 years and never found wrong.

That’s the name you give something that is supported by all the hard physical evidence, and contradicted by none of it.

We can all mince what the word “theory”, but the bottom line is that if hundreds of thousands of people aggressively measure something for fifteen decades and they all get the same answer then they’re probably not wrong.

stevaroni said:

We can all mince what the word “theory”, but the bottom line is that if hundreds of thousands of people aggressively measure something for fifteen decades and they all get the same answer then they’re probably not wrong.

Unless, of course, the answer in question is somehow offensive to certain religious fundamentalists solely because it contradicts a literal (mis)reading of the Bible.

About this Entry

This page contains a single entry by Reed A. Cartwright published on August 23, 2011 1:00 PM.

Criticisms of Dembski’s No Free Lunch go unnoticed … again and again was the previous entry in this blog.

The Planet of the Apes is the Third One from the Sun is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.

Categories

Archives

Author Archives

Powered by Movable Type 4.381

Site Meter