Theory of science communication

February 26, 2007 6:51 AM

Belief and knowledge- a primer on science communication
posted by Gyan (43 comments total)

The only reason this is even an issue is because of Creationists and their ilk actively trying to confuse everyone. There's no practical, every day reason to distinguish between things which are "scientific facts" or things for which there is ample evidence and things which are "true", nor is there any reason to do so as a scientist. The only time it matters is when debating creationists, and possibly global warming deniers.
posted by delmoi at 7:06 AM on February 26, 2007

As an evolutionary biologist, I am sometimes asked by non-biologists whether I believe in evolution. I usually reply that belief is not relevant—only whether evolution can be observed, and it can. It is like asking whether I believe that that apple I just dropped hit the ground afterwards.
posted by grouse at 7:25 AM on February 26, 2007 [1 favorite has favorites]

grouse, the non-biologists are probably referring to macroevolution.
posted by Gyan at 7:28 AM on February 26, 2007

Macroevolution is observable.
posted by DU at 7:31 AM on February 26, 2007

delmoi, though I agree with you for the most part, it's still important to point out when talking about jargon in any field, it's necessary to always make the distinction between the meaning of the shared vocabulary with layspeak. Otherwise, one unwittingly confuses the issues.
posted by creeptick at 8:00 AM on February 26, 2007

As an evolutionary biologist, I am sometimes asked by non-biologists whether I believe in evolution. I usually reply that belief is not relevant—only whether evolution can be observed, and it can. It is like asking whether I believe that that apple I just dropped hit the ground afterwards.

Bingo. That's my take altogether on belief in general. Belief is what you get when you're tired of pursuing the problem any longer.
posted by smallerdemon at 8:02 AM on February 26, 2007

As an evolutionary biologist, I am sometimes asked by non-biologists whether I believe in evolution.

That's a strange question, isn't it? It's like asking your family doctor if he/she supports western medicine.
posted by easternblot at 8:14 AM on February 26, 2007

Gyan, people who ask me about belief usually don't know what macroevolution is. These aren't people well-armed with creationist/intelligent design arguments, but merely people who are curious and sometimes slightly misinformed. In any case, the fact of evolution is simply the observation that life has changed greatly over time and is continuing to do so. While the exact mechanism (i.e. the theory of evolution) may still be under discussion, the fact that this has and does occurred is undisputed by scientists.

That's a strange question, isn't it?

Yes, for a while I was mystified that this happened multiple times. Eventually I realized it is a way of starting a conversation about the evidence for evolution.
posted by grouse at 8:30 AM on February 26, 2007

This dramatization feeds the popular image that all scientific knowledge is tentative. Much is tentative, but much is well understood and unlikely to be discredited.

As a scientist she should know that "well understood" and "unlikely to be discredited" are not be confused with fact. It is a basic tenet of science that no principle can be proven: scientific principles can only be disproven. All scientific knowledge IS tentative and scientists should be proud to say so.

It is like asking whether I believe that that apple I just dropped hit the ground afterwards.

Spoken like a biologist who has surrendered her scientific skepticism by accepting evolution as fact. Didn't Einstein observe that in certain frames of reference, Newton was horribly wrong and the apple never hits the ground?

I happen to believe that it is very likely that reproductive fitness is the reason man exists on Earth, but I'd be a fool to say it is unassailable fact.

Scientists make no case against Creationism by pretending they know another truth.
posted by three blind mice at 8:44 AM on February 26, 2007

three blind mice writes "Spoken like a biologist who has surrendered her scientific skepticism by accepting evolution as fact."

Evolution is clearly an irrefutably a fact. Species have changed over time; there's absolutely no doubt about this simple fact. You might as well be skeptical about the color of the sky.
posted by mr_roboto at 9:08 AM on February 26, 2007

It is clear that some people have misappropriated the word believe. You don't believe in God because there are clear reasons for believing in God... you have faith in God, if that.

Further, I'm not sure if anyone who claims to have faith in God really does. For the most part, Americans operate fanatically on a rational level when it comes to most transactions. Request a receipt for your purchase is customary. From tailors to mechanics to counting the vote, people are rabid about details and justifications in most aspects of their lives.

When it comes to God, they claim that they set their normal mode aside, and have "faith" instead. I'm not buying it. I think it's pretend, a very serious, very terrified kind of pretend, but pretend nonetheless. There is only so much cognitive dissonance a person can take, but pretending, well, we a nation of pretenders.
posted by ewkpates at 9:09 AM on February 26, 2007 [1 favorite has favorites]

threeblindmice:
If you have an "Apple" and "ground" then the apple will always hit the ground. To get to a different context, you need an environment that can not support human life. We still live in Newton's world.

Evolution is a fact, just like gravity. What is "Not Proven" is how it operates, not its existence. In fact, we understand evolution better than we understand gravity. But the existence of both is not in doubt, by the evidence at least.
posted by bornjewish at 9:11 AM on February 26, 2007

grouse, the non-biologists are probably referring to macroevolution.

"Macroevolution" is a bullshit term; Biologists use the word "Speciation" to talk about one species coming from another. Also, Speciation has been observed.

Spoken like a biologist who has surrendered her scientific skepticism by accepting evolution as fact.

That "scientific skepticism" serves no purpose other then to debate epistemology with creationists on the internet. It's a pointless waste of time, and dosn't improve science. For a theory that is very well established, there is no real reason to doubt it, other then to keep an open mind in response to new information.

Didn't Einstein observe that in certain frames of reference, Newton was horribly wrong and the apple never hits the ground?

Huh?
posted by delmoi at 9:35 AM on February 26, 2007

three blind mice: As a scientist she should know that "well understood" and "unlikely to be discredited" are not be confused with fact. It is a basic tenet of science that no principle can be proven: scientific principles can only be disproven. All scientific knowledge IS tentative and scientists should be proud to say so.

Well, the question then becomes can we call anything a "fact."

Spoken like a biologist who has surrendered her scientific skepticism by accepting evolution as fact. Didn't Einstein observe that in certain frames of reference, Newton was horribly wrong and the apple never hits the ground?

No, the beauty of Einstein's theory of gravity is that it collapses nicely into Newton's theory of gravity for most cases. Einstein's general and special relativity expands Newtonian mechanics, it doesn't entirely replace it.

The result of this is that a physicist or engineer using either Newton's or Einstein's mechanics will come to the same conclusion of the behavior of apples within measurable levels of error. (The behavior of astronomical bodies and bodies approaching the speed of light are another matter.)

I happen to believe that it is very likely that reproductive fitness is the reason man exists on Earth, but I'd be a fool to say it is unassailable fact.

Well, here is a case where extraordinary claims require extraordinary evidence. Until someone develops a comprehensive theory that provides an elegant alternative explanation for 150 years of peer-reviewed published research, there is not much point.

And my theme for the month is that it astonishes me how people have different standards for Darwinian evolution which they don't hold for electromagnetism, atomic theory, plate tectonics, or solar system evolution. All of these theories originated in the 19th century, and all of them have undergone substantial elaboration and revision in response to new evidence and insights.
posted by KirkJobSluder at 9:49 AM on February 26, 2007

When it comes to God, they claim that they set their normal mode aside, and have "faith" instead. I'm not buying it. I think it's pretend, a very serious, very terrified kind of pretend, but pretend nonetheless. There is only so much cognitive dissonance a person can take, but pretending, well, we a nation of pretenders.
posted by ewkpates at 12:09 PM EST on February 26

This is because for most people, belief in god is something they get from their family very early in life, and thus becomes part of their identity. Therefore, an attack on God is also an attack on their identity.

The mechanism is also self regulating - any doubt about God is quickly repressed when encountering others like them who do believe in God or when encountering others who are very different from them and do not believe in God or the same God.
posted by Pastabagel at 9:49 AM on February 26, 2007

Thanks to everyone else who responded to most of three blind mice's very well. I have two more to make:

Spoken like a biologist who has surrendered her scientific skepticism by accepting evolution as fact.

I was male, last time I checked... Yep, still am.

I happen to believe that it is very likely that reproductive fitness is the reason man exists on Earth, but I'd be a fool to say it is unassailable fact.

Any explanation involving "reproductive fitness" involves the theory of evolution, not the fact of evolution. You don't need to understand reproductive fitness to observe that speciation has occurred and still does.
posted by grouse at 10:25 AM on February 26, 2007

Good article. Here's the executive summary for those who don't feel like reading the whole thing:

If we set up science as just another belief system, we weaken its authority and dilute the power of our knowledge. If our "I believe" is heard in the sense of uncertainty, that weakens the strength of our assertion even more. We could, and I think should, excise the word "believe" from our vocabulary when talking about science.

The only reason this is even an issue is because of Creationists and their ilk

delmoi: I'm sorry, but that's simply not true. "Creationists and their ilk" are just a subset (and a relatively tiny one) of the vast number of people who don't understand how science works and how and why scientists "believe" things to be true. Since ordinary people are confused by the ways scientists talk about such things, and since they're not likely to learn better in the near future, it behooves scientists to learn to talk in ways that make sense to ordinary people, which is what the author is saying.
posted by languagehat at 10:26 AM on February 26, 2007

A recent ask.mefi which brought this problem clearly to light is grumblebee's question about the concept of "information" and how it is used in math/physics. It is also one of those words that laymen use and think they know but that physics has defined in a precise way which may sometimes counter intuition.

Science writers who fail to point out these distinctions, and in fact often capitalize on them to make sensational headlines, are doing everybody a disservice.
posted by vacapinta at 10:58 AM on February 26, 2007

"All models are wrong; some models are useful." G.E.P Box

I have to remind myself (and my students) of this frequently. Science provides models, some of which are useful for a while, some last a long time. Useful models are those that pay their way; they provide the means to predict outcomes beyond the observations used to formulate them. For example, Newtonian mechanics developed from the motion of things on earth and of the planets is helpful in predicting the motion of the stars and constellations. The atomic model developed from looking a few elements is useful for predicting the behavior of newly discovered elements and newly examined interactions of known elements. Quantum mechanics predicts strange behavior under extreme conditions that remarkably is observed when experimental conditions are created. Such is any scientific theory. It is only "true" in that it approximates how things work. It doesn't pretend to say why things happen, just how. The confusion of Creationists is that science is attempting to say why things are. As they cling to what their ancient books say, they must take issue with what current model is paying its way, in order that it not brush away their why along with their outmoded how.

Arguing with Creationists is ineffective at best. Communicating with those whose mind is open is best done with humility and honesty regarding the modest aims and claims of science. We only disserve ourselves as scientists when we try to take on more.
posted by Mental Wimp at 2:21 PM on February 26, 2007

The article was very condescending. She has an attitude that scientists must be very careful how they talk to the ignorant peasants in the village who do not understand the complexities of scientific logic.

I say we burn her.
posted by JParker at 2:44 PM on February 26, 2007

posted by mr_roboto:
Evolution is clearly an irrefutably a fact. Species have changed over time; there's absolutely no doubt about this simple fact. You might as well be skeptical about the color of the sky.

If creationists were good hair splitters they would likely argue that there is a very distinct difference between change (adaptation) and evolution. Changes in species are evidence of adaptation, not evolution. Simian apes are still present side by side with humans. They are very adapted, but not evolved (comparatively). Why? Adaptation is an irrrefutable fact. Evolution is undefined.
posted by RoseyD at 12:46 AM on February 27, 2007

If creationists were good hair splitters

Oh, but they are. Creationists who like to argue with scientists are skilled in all sorts of sophistry.

they would likely argue that there is a very distinct difference between change (adaptation) and evolution... Adaptation is an irrrefutable fact. Evolution is undefined.

Adaptation does not mean "change." Adaptation means change that increases the long-term reproductive success of the organism. It's actually a much stronger claim to say that adaptation happens than to say that evolution does. Evolution does not require adaptation, but adaptation requires evolution.
posted by grouse at 3:50 AM on February 27, 2007

I would agree if I could accept that survival is the meaning of evolution.
But I can't.
Simply surviving cannot equal the whatever 'evolving' is.

There would seem to be at least 2 axis involved here. At least one lateral (adaptive) and one vertical (evolutionary).

Cannot adaptation be counter evolutionary, as well? Consider cockroaches. Highly adaptive, highly reproductive. Just like they were since - - just about ever?
posted by RoseyD at 6:57 AM on February 27, 2007

I would agree if I could accept that survival is the meaning of evolution.

But no one ever said that survival is the meaning of evolution. As I said before, the fact of evolution is the observation that life has changed greatly over time and is continuing to do so. Change is the constant, not survival.

If you had an asexually reproducing bacterium with perfect replication fidelity, that would survive, but not evolve. But there are no bacteria that replicate their DNA perfectly every single time, so evolution happens.

Cannot adaptation be counter evolutionary, as well?

I think you might understand these terms backwards. No change can be "counter evolutionary." Change and evolution are the same thing. Evolution can be maladaptive though. A good example is how cheetahs have evolved such that "reproduction is constitutively impaired because cheetahs have tenfold reduction in sperm count, 70% abnormal sperm per ejaculate, and a high incidence of acrosomal defects."

Consider cockroaches. Highly adaptive, highly reproductive. Just like they were since - - just about ever?

You are mistaken. The cockroaches have actually changed quite a bit over the last few hundred millions of years. There is a vast diversity in more than 3,500 cockroach species. It's especially worth pointing out that termites probably evolved from cockroaches. But forget for a second the termite, which have obviously evolved quite a bit. If you look at even the vast differences between current cockroach species that are visually apparent to a layperson, you can see that they are only the same in that they are small (from our point of view) and somewhat cockroach-like. From a cockroach's point of view, one might decide that the primates are all the same because thy are large and somewhat monkey-like. Actually, in both cases, there are massive differences in size, shape, banding pattern, color, smell, and behavior. And if you could intensively study what goes on in their cells and genomes, you would find even more differences.
posted by grouse at 8:02 AM on February 27, 2007

RoseyD writes "There would seem to be at least 2 axis involved here. At least one lateral (adaptive) and one vertical (evolutionary).

Cannot adaptation be counter evolutionary, as well? Consider cockroaches. Highly adaptive, highly reproductive. Just like they were since - - just about ever?"

Your operating under a serious, but common, misconception. There is no "direction" or "axis" to evolution. Evolution is merely the process of biological change over time.
posted by mr_roboto at 8:31 AM on February 27, 2007

So if I change my perception of this I will have evolved? And if enough of us find satisfaction in the endless changing of our changey-ness we will be capable of surviving the inevitable onslaught of the irrationalist, non-adapters, who, in a fit of rage, instigate an environmentally stunting catastrophy that collapses a large portion of civilization (a potentiality only recently realized) leaving the dazed and confused survivors to rebuild from there? Is that about how it goes?

(I could add links to all the major conflicts that have been fought over less stuff worth fighting for, but that would be counter evolutionary to the conversatiion, me thinks.)

Biological changes do not make evolution, evolution makes biology change. In uniquely adaptive ways.
posted by RoseyD at 10:05 AM on February 27, 2007

Oh, and though I would certainly agree that biological change is continuous, it is far from being constant. A great deal of change is not a great deal of evolution. And necessarily so.

If environmental factors contribute to instability, collapse is going to happen. Collapse is a property of physical structures that can, but not must, lead to evolutionary change. Change is assured. Evolution is not in such periods of rapid change.

(: I hope were getting somewhere :)
posted by RoseyD at 10:22 AM on February 27, 2007

There is definite lack of clarity in the discussion regarding "evolution" vs. "adaptation" (in the biological sense; nevermind the conflating of biological with the everyday meanings). Adaptation can be biological (inherited or not) or behavioral. For example, opposing thumbs are biological adaptations, and using tools are behavioral adaptations (requiring skeletal and neuromuscular adaptation as well). Evolution refers specifically to changes in the distribution of inherited traits of individuals within a species, up to and including the point at which species diverge into separate species. Although the word "evolution" is often used in everyday speech to connote "improvement over more primitive forms," (e.g., "Dumping his girlfriend like that shows that he is not very evolved") this is really not how the term is used biologically. Rather, the theory of natural selection is used to explain systematic evolution that makes a species better adapted to its environment. New species sometimes evolve from these inherited adaptation, but these new species are not "better" than the old one, just more adapted to their particular environment. What does it mean to be "better adapted?" That, my friends, is the $10^6 question.
posted by Mental Wimp at 10:40 AM on February 27, 2007

RoseyD writes "Biological changes do not make evolution, evolution makes biology change. In uniquely adaptive ways."

You have a fundamental misunderstanding of the basic terminology and concepts. The word "evolution" has a definite and specific meaning to biologists. It is the process of biological change over time. Or more specifically, the change in a population's traits from generation to generation. You seem to be confusing a more colloquial use of the word (which I suppose was the point of the linked article).

Mental Wimp writes "What does it mean to be 'better adapted?'"

To be more likely to reproduce given a specific set of environmental conditions.
posted by mr_roboto at 11:43 AM on February 27, 2007

Adaptation can be biological (inherited or not) or behavioral.


So, can it be said that structural changes that elegance a new behavior are the "proof" of evolution, but the new behavior is the evolution and can proceed the organisms full adaptation to it, biologically?

I don't know if that's it, but it seems to make sense . . .
posted by RoseyD at 12:30 PM on February 27, 2007

Evolution refers specifically to changes in the distribution of inherited traits of individuals within a species, up to and including the point at which species diverge into separate species.

Actually evolution would go way past the point of speciation. It is quite sensible to talk about the evolution of the vertebrates, for example. The term microevolution is used to discuss evolution that occurs only within a species.

If you want to read some good explanations of evolution, the Understanding Evolution web pages at the University of California, Berkeley are excellent.

So, can it be said that structural changes that elegance a new behavior are the "proof" of evolution,

The structural changes are evolution. Changes in heritable behavior are also evolution. So are changes in genome sequence.

but the new behavior is the evolution and can proceed the organisms full adaptation to it, biologically?

Unfortunately I'm not sure I understand what you mean by this. Did you mean to say that "the new behavior is the evolution and can precede the organism's full adaptation to the new behavior?"

If so, that is a bit confused because not only is new heritable behavior a direct consequence of evolution, but so are the other changes, as I pointed out. Also organisms do not inevitably travel down a path of increased adaptation. You generally cannot measure a point where there is a "full adaptation" to anything—that implies some kind of global maximum that does not necessarily exist.
posted by grouse at 2:15 PM on February 27, 2007

No, I meant in reference to "changes" that would be differentiated as evolutionary in a way that is unambiguous side by side with changes that are merely "perturbations". In other words changes that have a significance as evolution in the truth being observed and described for a species.

If the species is changing in a way that merits the term evolution it is necessary to disambiguate what that means in relation to the species it refers to. Otherwise it's a meaningless term. Can it be said that this one is evolving because that one is, even though there is no actual change? Or simply because all species change, therefore change is evolutionary? What's the significance there?

Why use a term that describes nothing and confuses everything on the basis that if you don't believe it you don't get it? That's as silly as silly gets. Even Creationists understand that.

Well, not all -- but you know what I mean.
posted by RoseyD at 5:07 PM on February 27, 2007

RoseyD writes "Well, not all -- but you know what I mean."

No fucking idea, actually.

RoseyD writes "Or simply because all species change, therefore change is evolutionary? What's the significance there?"

Evolution is just a word that means "biological change over time". That's the sum total of its significance. It's not meaningless: it means "the changes in the traits of a biological population from generation to generation". That's the meaning. The changes are evolution. Evolution is the changes.
posted by mr_roboto at 5:32 PM on February 27, 2007

mr_roboto
Mental Wimp writes "What does it mean to be 'better adapted?'"

To be more likely to reproduce given a specific set of environmental conditions.

I don't thing that answers the question. I don't think it is that simple. Reproduction is actually one aspect of adaptation. Some species are confined to an environment wherein high rates of reproduction are necessary to overcome the high mortality rate of the young. Another species might have access to fewer food sources, so reducing the reproduction rate is adaptive. I think biologists often puzzle about why a certain adaptation is the response to a particular environment exactly for the reason that "better" is not well defined. It might mean getting smaller to avoid detection by predators or getting larger to discourage predation. Propagation of the species is ultimately what defines the success of a species, so I guess a simplistic definition would necessarily be retroactive: they didn't die out. But then, every species will eventually either die out or change. Even species that look and seem to function the same as they did necessarily have genetic shifts over time. The DNA mutates and some genetic changes stick because they are meaningless, even those in functional sequences. Are they better adapted? Maybe, because perhaps this genome is more robust.

I stand by my statement that "better adapted" is not easily nor currently well defined.
posted by Mental Wimp at 5:53 PM on February 27, 2007

In terms of what is happening at a genetic level we have different words to describe something you seem to be getting at. A single change from one generation to the next generation is called a mutation. If that change becomes fixed in the population, it is called a substitution, although people are frequently sloppy with this term.

It's all evolution. "Evolution" is not a meaningless term anymore than "change" is. Specifically, evolution is change through descent and genetic inheritance.

You seem to think the fact of evolution in this sense is not a significant idea, but it is one that was widely disputed amongst men of science as recently as the 19th century. And it is one that is still disputed by some creationists today, who hold that, for example, the fossil record was deposited by the flood, all the species that exist today have existed together since the dawn of creation without change, etc.

If you think it is unfathomable to argue that biological change over time, then you have already accepted the fact of evolution.
posted by grouse at 6:12 PM on February 27, 2007

Evolution is just a word that means "biological change over time". That's the sum total of its significance. It's not meaningless: it means "the changes in the traits of a biological population from generation to generation". That's the meaning. The changes are evolution. Evolution is the changes.

Okay, I have a fish on a hook here. Let me see if I can repair that.

To look at this scientifically, rather than as a competive sprint to the finish, let me suggest this. If we are considering the value of an investment and we want to know if it's profitable or not we can calculate it's yield. If we say there have been changes resulting in a loss and we call that result profit, the same as we would if there is a plus yield, then it's meaningless. We want our investment to grow, not just change. Change is not the measure of profit; profit is not the same as loss. These different values.

All change is not evolution just because it's change.

Am I really missing anything here? Please don't point me to a book to read.
posted by RoseyD at 6:53 PM on February 27, 2007

RoseyD writes "All change is not evolution just because it's change."

Yes it is. Again, this is a simple matter of definition. Your fundamental misconception seems to be an expectation that there is some sort of "direction" to evolution; some sort of "growth" or "profit". There is no such thing. Evolution is merely the change in a population's traits (and genes) over time.
posted by mr_roboto at 6:59 PM on February 27, 2007

If you think it is unfathomable to argue that biological change over time, then you have already accepted the fact of evolution.

Obviously I agree that there is evolution. I disagree that all change can be described by that term in a way that's useful. Extinction is change, and change that effects more than just the species going extinct. Is it therefore evolution?
posted by RoseyD at 7:03 PM on February 27, 2007

Am I really missing anything here?

Well for starters, most of my last comment. And a lot of what mr_roboto has been repeating about evolution having some sort of direction (it doesn't).

You keep purporting to define what evolution is, and to make it different from biological change over time. But it already has a definition that biologists use, and that is it.

Let's say we were talking about atoms being made of protons, electrons, and neutrons. You come along and say, "Actually atoms aren't made of other particles—they are indivisible. The word even comes from the Greek atomos which means indivisible. If atoms aren't indivisible the term is meaningless." You'd have your own definition for atom, and despite you thinking that the characteristic of indivisibility was pretty meaningful, the word would no longer be useful if you wanted to converse with chemists and physicists.

Extinction is change, and change that effects more than just the species going extinct. Is it therefore evolution?

Extinction is frequently caused by evolution as new competitors eliminate the capability of an existing species to survive. But no, the extinction event itself is not part of evolution, since the changes cannot continue over time. Evolution only occurs amongst living creatures reproducing. When an organism dies it is not an example of evolution.
posted by grouse at 7:28 PM on February 27, 2007

It's all evolution. "Evolution" is not a meaningless term anymore than "change" is. Specifically, evolution is change through descent and genetic inheritance.

Only to the current units of a species, which is a dynamic and purposeful collection, even if it's "purpose" is just to be. I get that. That is not incorrect at all.


But, what I really want to know is:
Ralphs machine shop is milling tools for tasks that no one has any intention of ever performing. All day long they invent new tools for things that no one will ever do. Is this a good investment? Given that all energy in the Universe is so stupid, I think it might be. It sounds evolutionary.

I've been looking at it carefully.

What do you think? Should I buy into it?
posted by RoseyD at 7:44 PM on February 27, 2007

Rosey: You're either not communicating effectively, or you're trying to tell a joke. Please either write more clearly or be more funny.
posted by mr_roboto at 7:50 PM on February 27, 2007

Alright, I guess that moving into further funnyness is beyond my reach today.

So, let me take a shot at clarity.


Unintellegent. I should have said unintelligent, not stupid.


Given that all energy in the Universe is so unintellegent . . ."
posted by RoseyD at 9:52 PM on February 27, 2007

Extinction is frequently caused by evolution as new competitors eliminate the capability of an existing species to survive. But no, the extinction event itself is not part of evolution, since the changes cannot continue over time. Evolution only occurs amongst living creatures reproducing. When an organism dies it is not an example of evolution.

Thank you, grouse. Much appreciated.
posted by RoseyD at 10:10 PM on February 27, 2007