What is the real deal with the peppered moth?

[Relates (Roger A. Sawtelle)]

@Christy

I wasn’t asking about politics or the meaning of life according to Roger. I was asking about science.

@Christy

There is one area where scientists are divided, and that is whether Natural Selection is Group selection or Individual selection. George C. Williams wrote an important book against Group selection which influenced Richard Dawkins and his Selfish Gene. Later he softened his stand in this area.

E. O. Wilson at first went for Group Selection, then agreed with Dawkins, but recently went back to Group Selection to the dismay of Dawkins. Stephen Jay Gould also disagreed with Dawkins on this point.

Group Selection vs Individual Selection mirrors the One and the Many issue of philosophy and theology. Life and Reality are unified, and so science, philosophy, and theology are connected.

[gbrooks9 (George Brooks)]

@Relates

Group Selection vs Individual Selection mirrors the One and the Many issue of philosophy and theology. Life and Reality are unified, and so science, philosophy, and theology are connected.

@Relates

I really don’t see how anyone can mandate a Universal on this particular idea. Sometimes evolution rests on a single mutation… and that carries the day for a new sub-population.

Sometimes evolution rests on a mutation steadily working its way through an entire population…

Vagaries of environment and circumstances are constantly fluctuating. Trying to mandate either as a Constant seems like a fool’s errand.

[glipsnort (Steve Schaffner)]

@Eddie

No, it’s not backwards. What I said was perfectly correct, epistemologically speaking.

Then your epistemology need work.

@Eddie

And in fact your own answer, despite your rebuke, confirms my approach. You looked up the observational evidence to establish the 1848 date!

I looked it up because you mentioned it. How does confirm your approach?

@Eddie

If the first dark moth had been observed before the Industrial Revolution, it wouldn’t matter a hoot what mathematical genetics speculated about the date of the mutation.

I already stated this in my previous response, but I must have been unclear. The genetic data tell us that the variant that increased in frequency was the result of a recent mutation, and was not circulating in the population for a long time. That is true if the first black form was seen in 1848, and it would be true if black forms had been seen every ten years for the past two thousand years. The observational evidence cannot distinguish between a long-term mixed population of dark and light forms and a light population in which dark mutants arise from time to time only to quickly disappear because of purifying selection. Only the genetic data can tell us that. In this case, what the observational evidence can suggest is that mutations that cause the dark pigmentation are likely pretty rare. But given how spotty the observational record is, that conclusion no doubt has a substantial uncertainty attached to it as well.

@Eddie

In any case, you admit that the date arrived at by mathematical extrapolation has “substantial uncertainty” about it

Sure. How would you characterize the date arrived at by the observational evidence?

[Jonathan_Burke (Jon)]

Charges of fraud misleading.

In your paper, Ms. Katrina Rider “asserts” the peppered moth story is a hoax. She conveys the impression that dead moths were glued to trees as part of a conspiracy of deception. She seems unaware that moths were glued to trees in an experiment to assess the effect of the density (numbers) of moths on the foraging practices of birds. Taken out of the context of the purpose of the experiment, the procedure does sound ludicrous.

But, should we blame Ms. Rider for her outrage upon learning that moths were glued to trees? No. Instead, I blame Dr. Jonathan Wells, who wrote the article she cites as her source of information. While he has done no work on industrial melanism, he has written opinion about the work. To one outside the field, he passes as a scholar, complete with Ph.D. Unfortunately, Dr. Wells is intellectually dishonest.

Majerus’ detailed explanation of the specific ways in which Wells misrepresented him, can be found here.

Preamble about my book and quotes from it: Dr Wells wrote:

"Majerus’s book includes a chapter entitled “The peppered moth story dissected.” Surprisingly, on the first page (117) of that chapter appear both of the following statements:

“…the basic peppered moth story is wrong, inaccurate, or incomplete, with respect to most of the story’s component parts.”

and

“…in my view…differential bird predation…in habitats affected by industrial pollution to different degrees, is the primary influence on the evolution of melanism in the peppered moth.”"

It is worth showing the way in which Dr Wells tries to distort what is said by someone else in good faith, by giving the whole of the sentence from which the first quote was culled, and the ensuing sentence…

"The findings of these scientists show that the precised description of the peppered moth story is wrong, inaccurate, or incomplete, with respect to most of the story’s component parts. When details of the genetics, behaviour, and ecology of this moth are taken into account, the resulting story is one of greater complexity, and in many ways greater interest, than the simple story that is usually related.

In other words, it is the text book precised account of the peppered moth story that I critise, not the scientific accounts published in peer reviewed scientific journals. Dr Wells as a scientist should understand the difference between the two, and should not attempt to take quotations out of context for his own ends. That is a policy followed by the worst aspects of the gutter press.

[glipsnort (Steve Schaffner)]

@Eddie

Why do scientific specialists in this area so often seem to make mountains out of molehills, turning a common-sense point into an unnecessary technical debate?

If experts keep telling you that your common-sense points are wrong, it’s probably because your common-sense points are wrong.

@Eddie

My point was very simple: If records show that a steady fraction of the moths (even if only a small fraction, say 10%) were dark even back in the 1600s, before the Industrial Revolution, then what happened in the Industrial Revolution was simply a case of natural selection altering the proportion of dark and light in the population

Right – that is your point. It’s wrong. Not certainly wrong, but probably wrong. If the dark phenotype had been present at 10% from the 1600s through the 1800s, and the genetic data show that the current dark phenotype is caused by a very recent mutation, then something other than your simple story of selection on an existing variant was probably going on. It’s wrong because neutral alleles at 10% in a large population are typically quite old – maybe 50,000 years old for something like a common insect. That’s inconsistent with the genetic data.

I can think of two scenarios in which both facts – the 10% historical phenotype and the genetic evidence for a recent mutation – are true. One is that the dark phenotype was caused by a recent mutation (say in the 1500s) and rose rapidly to 10% because of positive selection. In that case, something other than the Industrial Revolution was at least partly responsible for the rise of the dark phenotype, since it occurred before the IR. The other is that the modern dark phenotype is the result of an independent, very recent mutation, and that it replaced the previous dark phenotype. In that case, selection was likely operating on something other than the dark coloring, since the existing dark allele wasn’t selected for.

Now, there are observations that could change my assessment of the situation. For example, if the entire population showed signs of having rapidly expanded within the last few hundred years, then a 10% neutral variant would have a higher probability of being young. Or if there were a large inversion around the causal allele, then the mutation might not actually be recent. But these possibilities can only be explored by learning more about the genetics of the population, not by simply ignoring the genetics.

[Chris_Falter]

@Eddie

What I would be unhappy about would be any tendency of theoretical scientists to deny empirical data gathered by past observers on the grounds that it does not fit with their mathematical extrapolations.

Observations of a stochastic process always require a probabilistic context to be correctly incorporated into a theory. The criticisms I have seen lobbed at evolutionary biologists, however, often do not perform the probabilistic analysis correctly, if at all.

Fortunately, @glipsnort has introduced the genomic evidence that points to a recent mutation as the source of black coloration in the moths, so the scientific process seems to be proceeding the way it should. You should sleep well tonight with this reassurance. Good thing: you’ve got a lot of teaching and writing to do! (Godspeed in those endeavors, btw.)

@Eddie

It’s an example of “natural selection,” though, in both popular and technical usage – and I’m quite happy to call it that.

And that’s how it’s always been portrayed in the scientific literature I’ve read. You have complained, Eddie, about evolutionary biologists’ supposedly making mountains out of molehills, and supposedly claiming that this single experiment constitutes Q.E.D. proof of the most important theory in biology Your prose made me chuckle, Eddie. The scientific community has never, AFAIK, claimed anything remotely close to that. Perhaps you could provide a link to some outrageous quote I never read?

Surely your indignation would be put to better use were it to be directed at Islamist terrorists or politicians who tell audacious lies. Due to unfortunate recent events, we have great need of your logic and righteous anger on this side of the pond.

[Chris_Falter]

@Eddie

I made clear (though of course it is impossible for me to force people here to read my clarifications or pay any attention to them before they react) that I was speaking of popular presentations, not what was written in technical journal literature.

Really? Here’s your most recent statement on the matter:

@Eddie

Why do scientific specialists in this area so often seem to make mountains out of molehills, turning a common-sense point into an unnecessary technical debate?

I see you wrote this earlier:

@Eddie

even if speciation did take place, that would not be a problem for me, or for Behe, or for ID – and I was commenting only on the claim in popular books that the selection of one variety over another was “evolution.” It isn’t “evolution” in the sense that the public will understand the term, even if it’s “evolution” in a specialized sense that population geneticists use. So it’s misleading to call it “evolution” in a popular book aimed at people who will misunderstand the meaning of the term.

If the general public misunderstands something, I am not surprised. We just elected a guy on this side of the pond who says five impossible things before breakfast, every day. Or as Mencken put it, “Nobody ever went broke underestimating the intelligence of the American public.”

I’m not inclined to share your criticism of vocabulary among scientific writers. I’ve read the same literature as you, so far as I can tell, and I never once came away with the same impressions you have.

btw, if you happen to notice when Wells’ new edition is published, btw, please let me know. I’m sure it will be interesting.

Godspeed,

[Relates (Roger A. Sawtelle)]

Continuing the discussion from What is the real deal with the peppered moth?:

@gbrooks9

Vagaries of environment and circumstances are constantly fluctuating. Trying to mandate either as a Constant seems like a fool’s errand.

George, if something is “constantly fluctuating,” then this changing is a “Constant.” I see nothing foolish in this although it does not conform to what we usually consider a constant. We need to think “outside the box.”

My position is that changes in the environment which are constant, and follow an overall pattern, which drives variation and evolution as found in the Peppered Moth story. If you have exceptions to this rule, please bring them up.

[Christy (Christy Hemphill)]

@Relates

George, if something is “constantly fluctuating,” then this changing is a “Constant.”

You can’t really do that with words Roger. Just because a verb can be modified by the adverb ‘constantly’ does not mean that said action can be interchanged with the noun ‘constant.’ ‘Constantly’ and ‘a constant’ have etymologically related, but not interchangeable meanings. Then you switch to the adjective ‘constant,’ which actually is more interchangeable with ‘constantly,’ but you act like that sentence “changes in the environment which are constant (i.e. happen constantly)” is somehow equivalent to “changing is a constant.” But “changing is a constant” means something different. This kind of playing around with words habit makes trying to understand what you are saying and following your logic very frustrating.

[gbrooks9 (George Brooks)]

@gbrooks9

@Relates

I really don’t see how anyone can mandate a Universal on this particular idea. Sometimes evolution rests on a single mutation… and that carries the day for a new sub-population.

Sometimes evolution rests on a mutation steadily working its way through an entire population…

Vagaries of environment and circumstances are constantly fluctuating. Trying to mandate either as a Constant seems like a fool’s errand.

@Relates

So, Roger, what exactly is CONSTANTLY happening? Sometimes a population changes because of a single mutation … sometimes a population responds to group selection factors.

All I can see being demonstrated is: “Something different is happening all the time!”

[gbrooks9 (George Brooks)]

@Eddie

I repeat: I have no problem with the peppered moth as an example of “natural selection” – with the provisos I gave. I object to it as an example of “evolution” – unless the user defines “evolution” in some narrow population-genetics fashion (e.g., “change in allele frequency”) so as to distinguish it from “evolution” in the sense of “descent with modification from bacterium to man.”

As I said very early in this discussion … the inherent limitations of the Moth study makes for a less than satisfactory discussion, compared to the potential of the high-speed video of bacteria evolving in the face of an increasingly toxic environment.

[Relates (Roger A. Sawtelle)]

[quote=“Christy, post:57, topic:26141”]
You can’t really do that with words Roger. Just because a verb can be modified by the adverb ‘constantly’ does not mean that said action can be interchanged with the noun ‘constant.’
[/ am not playing with words. I am using words as they are intended to reveal meaning. The question is, Can change be a constant? I say yes even though we generally think based on our Greek philosophical bias that change and constant are opposites.

The ancients believed that the earth did not move, that the earth was “constant,” and this was is basic to Aristotle’s system of thought. They also said that then Bible says that the earth does not move. Galileo got into trouble when he challenged this.

My research indicates that the Bible does not say that the earth does not move, but that God established or fixed the earth. To the ancient mind this meant that the earth did not move, but to my modern mind this meant that God established the earth in her orbit around the sun, which has not changed.

The earth does move, which means that it does change position in time and space, and yet that move is constant, so the earth does not move outside the orbit God created for her. Change and Constant are not opposites, when thought of scientifically and theologically.

George made the observation that the environment is constantly changing, and came up with the conclusion that it is foolish to try to find any order in it. I said that if the only constant in life is change, then change is a constant. That is true, just like the only constant is life is death.

The question that you and I have been arguing is: Can humans claim that life and reality have order or not? I say Yes, and you and George as I hear you, say No. Taken as a whole, theology, philosophy, and science agree that life and reality have meaning and order. This is the only claim I am making.

Now we might not understand how this order works, but because we do not live in a world of chaos, although some people seem hell bent to make this world into hell and chaos. Nonetheless underneath the change of this world is God’s scientific order and God’s moral order. Just because we do not see it does not mean it is not there and we should deny its existence and give up our search for it.

[Chris_Falter]

Hi Eddie,

I agree with you that the original peppered moth experiment is just one small piece of evidence pertaining to evolution, and that by itself it does not prove evolution.

I reiterate that I have not, even in the popular literature, seen the misrepresentations that you profess having read.

[benkirk (Benjamin Kirk)]

@Eddie

I repeat: I have no problem with the peppered moth as an example of “natural selection” – with the provisos I gave. I object to it as an example of “evolution” – unless the user defines “evolution” in some narrow population-genetics fashion (e.g., “change in allele frequency”) so as to distinguish it from “evolution” in the sense of “descent with modification from bacterium to man.”

That’s not a repeat, as you’ve changed your claim.

You wrote this 19 days ago:

@Eddie

It’s when pop science books and blog sites, etc. claim that the peppered moth proves “evolution” – as if such trivial variations altering their proportion in the population demonstrates the truth of “bacterium to man” (which is what the layman understands by “evolution”) – that I object.

You have yet to provide a single case of what you claimed happens quite often. As Chris says, I have never seen what you claimed to be the norm. Do you have even a single example of anyone claiming that the peppered moth proves evolution?

And why would you describe evolution as “bacterium to man” when there is no evidence to suggest that the common ancestor of you and a bacterium was a bacterium? Why portray the nested hierarchy as a ladder?

Do you have anything other than straw men to offer here, Eddie?

@Eddie

…my alarm bells rang before posting a reference to Wells’s work on the peppered moth.

Wells hasn’t done anything resembling work on the peppered moth. You have a strange idea of what constitutes work in academia.

[glipsnort (Steve Schaffner)]

@Eddie

You mean, inconsistent with the extrapolations that population geneticists make from the genetic data.

Sure. Just like you’re talking about the extrapolations made by natural historians from observational data. Look, do you have any actual reason for rejecting the conclusion based on the genetic data?[quote=“Eddie, post:52, topic:26141”]
You understand my meaning exactly. I am saying that is logically possible that the dark moth already existed and constituted a certain fraction of the population. Are you saying it is logically possible but biologically impossible?
[/quote]
I’m saying what I said: such a possibility is inconsistent with the genetic data. You seem to want to ignore the genetic data.[quote=“Eddie, post:52, topic:26141”]
You seem to think that I am debating with you about how and when the dark variety of moth first arose.
[/quote]
Debate? No, I don’t think we’re debating that at all. You have made inaccurate statements about a field I know something about. I have corrected them. That’s all.

@Eddie

I repeat: I now assert nothing firm about the existence of the dark variety before the Industrial Revolution, about the date of origin of the dark variety, or about the causes of the origin of the dark variety. I thought I had read that both varieties existed before the IR, and it follows logically from that fact (if it be a fact) that what the IR did was change the proportion between the varieties, due to natural selection.

I understand perfectly what you’re claiming. What I’m telling you – repeatedly – is that your “fact” is not a fact. It’s very likely false. Your conclusion does not follow from your premises. [quote=“Eddie, post:52, topic:26141”]
What I would be unhappy about would be any tendency of theoretical scientists to deny empirical data gathered by past observers on the grounds that it does not fit with their mathematical extrapolations. That would amount to a tyranny of theory over data – and we have at least one biologist in this forum [not yourself, to be sure, but still…] constantly preaching that science is all about data, data, and data.
[/quote]
As far as I know, the only one in this thread who proposes to ignore empirical data is yourself. My suggested scenarios assumed that the hypothetical early observation of dark moths was accurate. The only thing I’ve rejected is your conclusion from those observations. [quote=“Eddie, post:52, topic:26141”]
I notice you have not commented on the scientific ethics – if such a thing was in fact done – of gluing moths’ feet to tree trunks to fit in with the “birds pick off moths from tree trunks” selectionist story
[/quote]
The list of things I have not commented on in my life is quite long.