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Author Topic:   Peppered Moths and Natural Selection
MartinV 
Suspended Member (Idle past 5906 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 211 of 350 (354799)
10-06-2006 1:46 PM
Reply to: Message 208 by Akrid
10-04-2006 9:01 AM


Akrid writes:
And that DNA has a set number of information. I’m sure he’s wrong in his interpretation of how DNA works, but I'm not knowledgeable enough about it myself to finish the conversation.
Anyway your post is not so much off topic as it seems at first glance. Let me cite some Majerus words from creationist link:
"Creationist site on pepperd moth"
There is no doubt that in some species, melanic forms that existed as polymorphisms before the widespread industrialisation, have increased in industrial areas subsequently. However, in other cases, new melanic forms have arisen by mutation and then spread in industrial regions of Britain, despite the existence of melanic forms in other parts of Britain. (Melanism: Evolution in Action, Michael E. N. Majerus, 1998, p198)
.
.
.
The reasons why industrial melanism did not develop in these species earlier is probably serendipitous: the relevant mutation simply did not arise in the right place at the right time.
(Melanism: Evolution in Action, Michael E. N. Majerus, 1998, p198)
As we see, mutation would have coincided with industrial revolution. It is very
strange. As far as I know mutation means, that some existing gene changes some nucleotides inside for another ones only by chance. This phenomenon should lead to melanism. Neodarwinism seems to explain some melanism due to these mutations suported by subsequent selection. Anyway these and other mutation would have arousen by chance througout ages. Yet it seems to me improbable that this one - melanic - just coincided with industrial revolution to survive. I would say, that genes responsible for melanic forms were either already present in DNA of moths and derepressed (as Davison states) or they aroused by no way by chance. The second case means, that organism somehow know, that it would be better for it to look melanic due crypsis and coded somehow the information in DNA in order to pass it to next generations. Or - most probably, but of course I can give no evidence, its just speculation - insects somehow in some cases prefer to look like prevalent surroundings and coded information into DNA. DNA for me represents only "library" to which an organism write or read information as needed. DNA and chromosomes have no any meaninig withou "reader" and no information value without cell (zygota at first moment) which knows what and when to draw from it and how to interpet the drawn information.

This message is a reply to:
 Message 208 by Akrid, posted 10-04-2006 9:01 AM Akrid has replied

Replies to this message:
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Dr Adequate
Member (Idle past 362 days)
Posts: 16113
Joined: 07-20-2006


Message 212 of 350 (354820)
10-06-2006 3:01 PM
Reply to: Message 211 by MartinV
10-06-2006 1:46 PM


Yet it seems to me improbable that this one - melanic - just coincided with industrial revolution to survive.
No-one said it did; the claim was that natural selection increased the frequency of the form. This is evidence of natural selection, not of a novel mutation.

This message is a reply to:
 Message 211 by MartinV, posted 10-06-2006 1:46 PM MartinV has not replied

  
Akrid
Inactive Member


Message 213 of 350 (354863)
10-06-2006 5:43 PM
Reply to: Message 211 by MartinV
10-06-2006 1:46 PM


So let me get this straight, the creationist are arguing that because the industrial revolution was man-made it’s unnatural and makes the peppered moth evolution a product of mans meddling?
If that is the or a argument they are using here, I'd reply;
It doesn’t matter if we stimulated the mutation or not, all that matters is something affected the moths. It stands to reason that natural events have occurred through out the history of the earth that has no doubt created effects of one kind or another. Volcanic Ash, Temperature change, geography (plates moving or animals being swept to different location). To use the effects of something man-made holds just as much validity in pointing out an effect of evolution, as long as the man-made effects where not purposely to stimulate evolution. There is nothing magical about a man-made effect that takes them out of the category of environmental effects, there is nothing that makes man made effects unsuitable for examples of effects that can cause evolution.
I don’t know if this is what they where arguing, but regardless I come across this in such debates often. I would compare this to say; trying to discover if a person bleeds naturally when the skin is breeched. Do we really need to see a person accidentally get a cut in the wild to see if bleeding occurs naturally? Do we not gain information about the nature of bleeding from man-made cuts? It would be stupid to say bleeding does not ever occur because I have never seen it occur naturally and if somebody purposely causes bleeding it doesn’t count. If we do something and the effect induces evolution in a animal or ourselves it tells life evolves (and we can witness much of this in adaptation, why is evolution excluded?).
Edited by Akrid, : Added some "?" marks and stuff

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MartinV 
Suspended Member (Idle past 5906 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 214 of 350 (354954)
10-07-2006 5:55 AM
Reply to: Message 206 by RAZD
10-03-2006 11:15 PM


Re: obfustication ... and STILL Clutching at straws to ignore the reality ...
RAZD writes:
I say this because nothing you have provided refutes this point -- that observation and data from numerous studies show that (a) "the moths normally rested where the typica variety had the most visual protection from bird predation in unpolluted forests" and (b) "the moths normally rested where the carbonaria variety had the most visual protection from bird predation in polluted forests"
We are spinning in a circle. Observations are scanty ant imperfect. Thats why Majerus who knows of topic much have only "view" and no "evidence":
It is our view that the peppered moth habitually rests by day on the undersurfaces of horizontal branches and twigs, and that its colour pattern provides an effective cryptic match...
And again Grant:
In truth, we still don't know the natural hiding places of peppered moths.
RAZD writes:
So you concur that preferential predation of the moths occurred, that observation and data from numerous studies show that Majerus' conclusion is valid
No. I concur only, that in an unnatural conditions in aviary we observed something like preferential predation and maybe preferential predation was cause of decline of returned peppered moths when released during day and did not pick up habitual resting places but first ones they hit on. These two observations are no way sufficient as evidence of hypothesis that decline of peppered moths was caused by preferential predation during industrial revolution.
You tell me.
.
.
Thank you for pictures, very interesting indeed. I like them. Anyway as photos from from industrial area they do not support your claim, that also forests were so poluted, that there were "virtually NO light background".
Given that all
pictures of Oak Beauty, Biston Strataria, moths on google are significantly darker than Biston betularia typica and in fact are closer to carbonaria, the answer should be obvious. In case it isn't, it is because there is just not much difference between the two varieties of Biston stratari.
From the picture I would say that the difference is sensible. That melanic form is distingishable enough is clear from Majerus consideration (creationist link):
The case of the peppered moth's closest British relative, the oak beauty, Biston strataria (Hufnagel) (Fig. 7.17), is instructive in this regard. This species has a melanic form, f. melanaria, which is a recent and common industrial melanic in the Netherlands, but has never occurred at appreciable frequencies in Britain.
In your next post you wrote:
So there is a clear, distinct and unambiguous shift in the proportions of populations between the varieties of the Oak Beauty Moth, Biston strataria, a related species that also inhabits the same general environment as the Peppered Moth, Biston betularia, ...
Yet Majerus do not see this as unambiguous as you proposed:
However, the melanic mutation in the oak beauty seems never to have arisen in this country in favourable circumstances, with the consequence that it has not successfully established itself here.
According Majerus it is due "lack of industrial poly-morphism in this species in Britain" an so on, but the case is very intstructive. B.strataria rest on tree trunks and according neodarwinists who are so fond of making pictures of glued moths exactly there to prove selection advantage of crypsis, they should have been extra good prey for birds. But this was not the case, so Majerus came with explanation of insufficient occurences and so on.
BTW you did not addressed my question, if melanism could not be explained due migration of more conspicuous form to more favourable areas.

This message is a reply to:
 Message 206 by RAZD, posted 10-03-2006 11:15 PM RAZD has replied

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MartinV 
Suspended Member (Idle past 5906 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 215 of 350 (354955)
10-07-2006 6:22 AM
Reply to: Message 213 by Akrid
10-06-2006 5:43 PM


Akrid writes:
It doesn’t matter if we stimulated the mutation or not, all that matters is something affected the moths.
It is coincidence, that soots are dark. If it were red, so we would
have observed red moths morphs? Do we ever observed moths that due mutation of gene have green/blue/yellow/ wings? BTW. bricks are red, so was there ever mutation of moths to brick color, that can survive on wall in cities? Or mutation is restricted to white-dark gamut and each generation release some individuals so to say to see if there is any advantage of this crypsis? Do we know green morphs which can eventualy rest on leaves? Why not? As far as I know moths as family lavish in colors almost as butterflies. If look like leachens why not as leaves?

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RAZD
Member (Idle past 1482 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 216 of 350 (354960)
10-07-2006 8:08 AM
Reply to: Message 215 by MartinV
10-07-2006 6:22 AM


More Ignorance.
If it were red, so we would have observed red moths morphs?Do we ever observed moths that due mutation of gene have green/blue/yellow/ wings? BTW. bricks are red, so was there ever mutation of moths to brick color, that can survive on wall in cities? Or mutation is restricted to white-dark gamut and each generation release some individuals so to say to see if there is any advantage of this crypsis? Do we know green morphs which can eventualy rest on leaves? Why not?
Because mutation is not directed. There is no choice to be red or blue or green involved and no mechanism to cause this. There is no "chameleon" process where cryptic patterns are chosen {to appear in order} to match backgrounds.
This is a common misconception of evolution mutation & natural selection mechanisms by creationists and it leads to more misunderstanding on their part of how evolution works.
Mutation is random, unpredictable, undirected. It's like drawing a lottery ticket. Whatever mutation happens is then subject to the filter of natural selection. The mutation needs to occur for natural selection to operate, and there is no mechanism to force a 'desired' mutation to occur.
Enjoy.
Edited by RAZD, : added in {}'s

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This message is a reply to:
 Message 215 by MartinV, posted 10-07-2006 6:22 AM MartinV has replied

Replies to this message:
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RAZD
Member (Idle past 1482 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 217 of 350 (354980)
10-07-2006 12:56 PM
Reply to: Message 214 by MartinV
10-07-2006 5:55 AM


further obfustication with Oak Beauty ...
From the picture I would say that the difference is sensible. That melanic form is distingishable enough is clear from Majerus consideration (creationist link):
The case of the peppered moth's closest British relative, the oak beauty, Biston strataria (Hufnagel) (Fig. 7.17), is instructive in this regard. This species has a melanic form, f. melanaria, which is a recent and common industrial melanic in the Netherlands, but has never occurred at appreciable frequencies in Britain.
Yet Majerus do not see this as unambiguous as you proposed:
However, the melanic mutation in the oak beauty seems never to have arisen in this country in favourable circumstances, with the consequence that it has not successfully established itself here.
So now you are saying that there was no appreciable melanic population of the Oak Beauty in England for the effect of Natural Selection to operate?
Before you implied there was (along with the false implication that it should have exactly the same results as Biston betulari). Your link also mentioned an increase in the melanic form in this period -- was it lying about this evidence?
The issue of Oak Beauty is clearly different from Peppered Moths as
  • they have a significantly different appearance from either Peppered Moth variety AND
  • there is much less difference between "melanic" and "typical" varieties of Oak Beauty AND
  • neither Oak Beauty variety is more "soot-like" than the other (one dark brown, one darker brown?) AND
  • thus there would be no real relative advantage of one over the other due to the increased coverage of the environment by soot.
If both populations would be similarly affected by a sooty environment, then there would be no selective advantage of one over the other as is the case with Biston betulari.
Until there is a demonstrated advantage of one over the other there is no argument made by using this example - except for the argument that creat(ort)ionist(a) sites misrepresent the truth of the matter.
This still does not in any way invalidate the data based on the observations and studies made of Biston betulari. That data still shows preferential predation of moths based on different camouflage ability in different environments where different existing varieties have different survival fitness.
Enjoy.

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This message is a reply to:
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RAZD
Member (Idle past 1482 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 218 of 350 (354985)
10-07-2006 1:49 PM
Reply to: Message 214 by MartinV
10-07-2006 5:55 AM


frantically Clutching at straws to ignore the reality ...
We are spinning in a circle. Observations are scanty ant imperfect.
You are spinning in a circle, first arguing one way and then the other, with no consistent theory or argument.
Explanations are based on the evidence available, and these "scanty ant imperfect" observations are still sufficient to show that the effect of differential predation on the relative populations two varieties of moths, first to the benefit of the carbonaria variety in polluted forests and then to the benefit of the typica variety in non-polluted (or de-polluted) forests.
There was clear, distinct and unambiguous evidence of preferential predation by birds of the moths.
There was, and still is, no other mechanism proposed that accounts for this clear, distinct and unambiguous evidence as well as Natural Selection.
There was, and still is, no other mechanism proposed that accounts for the equally clear, distinct and unambiguous evidence that the populations of moths changed over time downwind of pollution centers, that first showed an increase in the proportion of carbonaria forms from rare to predominant, and the decrease in proportion of typica forms from predominant to rare, as a result of the effect of the pollution on the environment.
There was, and still is, no other mechanism proposed that accounts for the equally clear, distinct and unambiguous evidence that the populations of moths changed over time downwind of pollution centers, that first showed an increase in the proportion of typica forms from rare to predominant, and the decrease in proportion of carbonaria forms from predominant to rare, as a result of the effect of the cleaning up the pollution in the environment.
These two observations are no way sufficient as evidence of hypothesis that decline of peppered moths was caused by preferential predation during industrial revolution.
And yet you have still to provide any alternative explanation that does explain the observed data.
You reject the conclusion that follows from the evidence because it invalidates your pet hypothesis and not because of any logical reasoning. You cite both Grant and Majerus, and yet both of them conclude that preferential predation occurred, the objections they raise are insufficient in their opinion to invalidate the theory or the conclusion based on the available evidence:
  • Moths in pre-industrial England were predominantly of the typica variety, with some relatively rare occurrences of carbonaria variety moths being recorded.
  • Moths in industrial England in areas downwind of heavily industrial areas were found to be predominantly of the carbonaria variety, with some relatively rare occurrences of typica variety moths being recorded.
  • Moths in rural areas of England distant from heavily industrial areas were still predominantly of the typica variety, with some relatively rare occurrences of carbonaria variety moths being recorded.
  • CONCLUSION: Something in the polluted areas was causing the populations of carbonaria variety moths to rise, or the populations of typica variety moths to decline, or both.
  • DISCUSSION: Possible causes are (1) a kind of "Lamarckism", where moths that become sooty breed sooty offspring, (2) a kind of "Mutationism", whereby mutations are directed to occur to increase camouflage ability in later generations, (3) the process we call "Natural Selection" where already existing variations have different survival fitness in different environmental situations, and (4) a selective migration process where unfit moths leave areas where they are more "at risk" for predation.
  • Moths placed (not glued) on trunks were found and consumed by birds in direct relation to their (human and bird) perceived camouflage level on a non-polluted tree trunk - demonstrating that birds saw the least camouflaged (carbonaria) moths first and the most camouflaged (typica) moths last.
  • Moths placed (not glued) on trunks were found and consumed by birds in direct relation to their (human and bird) perceived camouflage level on a polluted tree trunk - demonstrating that birds saw the least camouflaged (typica) moths first and the most (carbonaria) camouflaged moths last.
  • CONCLUSION: This demonstrates preferential predation actually occurs in both cases. "Lamarkism" cannot explain this result as it occurs in existing individuals. "Mutationism" cannot explain this result as it occurs in existing individuals. Migration cannot explain this result as there was no movement of the moths.
  • DISCUSSION: Natural Selection is not just the best explanation of the observed clear, distinct and unambiguous evidence of preferential predation of moths in these cases, it is the only one of these theories that explains the results of these cases.
  • Moths marked and released in an unpolluted forest and recaptured the following day showed a higher proportion of the most camouflaged (typica) moths (according to the fixed moth study results) survived during that interval than the least camouflaged (carbonaria) moths (again according to the fixed moth study results).
  • Moths marked and released in an polluted forest and recaptured the following day showed a higher proportion of the most camouflaged (carbonaria) moths (according to the fixed moth study results) survived during that interval than the least camouflaged (typica) moths (again according to the fixed moth study results).
  • CONCLUSION: This demonstrated that preferential predation actually occurred in both cases OR that moths preferentially migrated away from their release points OR that both occurred. "Lamarkism" cannot explain this result as it occurred in existing individual populations. "Mutationism" cannot explain this result as it occurred in existing individual populations.
  • DISCUSSION: based on these two studies alone the "Lamarkism" and "Mutationism" theories can be eliminated as they do not explain the observed results of these studies. This leave preferential predation and preferential migration as the two remaining possibilities that explain the observed results.
We know that preferential predation occurs from the first study. There is no need to discuss whether preferential predation occurs or not, as it has been demonstrated. The results of Kettlewell's experiments are sufficient to demonstrate this.
The theory of preferential predation is sufficient to explain all the observed data - on it's own.
The question remaining then is whether preferential migration can be an additional part of the equation.
BTW you did not addressed my question, if melanism could not be explained due migration of more conspicuous form to more favourable areas.
I'll take this to mean the theory of preferential migration noted above. If this is not what you are arguing then feel free to correct that impression.
We do know that moths may select preferred resting places where they are available, so that the ones with less protection may be inclined to travel farther in search of preferred resting places. This could result in the more unfit moths choosing to travel further than normal in an attempt to get away from unfavorable conditions, whether those are polluted forests for typica moths or non-polluted (de-polluted) forests for carbonaria moths. This would be a cause for preferential migration of the different moth varieties.
If preferential migration were the only cause of this observed phenomena then in areas surrounding polluted forests there should be (1) an increase in typica moths (that come from polluted areas) and (2) a decrease in carbonaria moths (that went into polluted areas). This would result in an increased proportion of typica moths over carbonaria moths in areas surrounding polluted forests.
This was not observed: the proportions of typica moths over carbonaria moths in rural areas remained essentially the same as they were in pre-industrial England. Further, the charts of moth densities show no increase in proportions of typica moths over carbonaria moths in areas surrounding polluted areas. For the effect to be significant enough to explain the proportions of carbonaria moths over typica moths in the polluted areas there would have to be a equally noticeable increase in the proportions of typica moths over carbonaria moths in the surrounding areas. Do the math eh?
Furthermore, increased mobility of less protected moths looking for safe resting places does not necessarily result in migration out of an area, as they are as likely to travel in one direction on one flight as another. Flying back and forth across an areas does not get you out of it.
For a moth to choose a direction and stick to it night after night there would need to be some cause for choosing that direction. A full moon, or bright lights in a distance for instance (as we know moths are attracted to light). This would apply to all the moths, and again should result in a marked pattern of increased proportions of typica moths over carbonaria moths on one side of a polluted area (from typica moths leaving polluted areas) with a similar increased proportions of typica moths over carbonaria moths on the other side of a polluted area (from carbonaria moths leaving the non-polluted areas).
This would concentrate the effect in a line of migration and would also have to be significant enough to be observed outside the polluted areas in order to account for the observed change in population proportions within the polluted areas with increased the proportions of carbonaria moths over typica moths there . Again, this was not observed: the charts of moth densities show no increase in proportions of typica moths over carbonaria moths in areas surrounding polluted areas.
The theory of preferential migration is not sufficient to explain all the observed data - on it's own.
The theory of preferential predation is sufficient to explain all the observed data - on it's own.
There is another way that increased mobility of the more "at risk" moths can result in a change in proportions of (1) carbonaria moths over typica moths in polluted areas and (2) typica moths over carbonaria moths in non-polluted (or de-polluted) areas, that would not affect the proportions of moths outside the areas of concern.
If the more "at risk" variety is flying for longer periods of time than the less "at risk" variety in order to find a safe resting place, then that means they are spending proportionally more "air time" when they are active - at night - and when they are subject to bat predation.
Bat predation would not, could not, select based on coloration, as noted before, but there would be an effect of bat predation based on the proportion of moth-hours in the air at any one time.
If moths more "at risk" of bird predation by day engage in modified behavior to escape bird predation by increasing their "air time" at night, then they will be increasing the proportion of moth-hours (compared to moths that don't modify their behavior) that they are exposed to bat predation, which will result in more predation by bats of moths spending more "air time" than other moths.
This hypothesis is untested, and so we do not know what proportion of the result is from such predation, BUT:
This is still natural selection.
In this case, Natural Selection for behavior favoring typica moths spending less night "air time" than carbonaria moths in non-polluted areas and favoring carbonaria moths spending less night "air time" than typica moths in polluted areas.
AND
This is still due to bird predation, as the behavior is engaged in order to avoid bird predation during the day - the bats don't care about the colors and the relative camouflage ability, only about moths flying at night.
AND
This is still a result of changing environment from non-polluted to polluted to de-polluted on the relative fitness of two different varieties of already existing moths of the same species, causing a population shift from one to the other and then back.
ie - the result is still a change in population proportions due to bird predation and industrial pollution.
Or as Majerus still concludes (based on his knowledge of all the data, and the shortcomings and problems):
quote:
The rise in frequency of the dark form of the moth (carbonaria) and a decrease in the pale form (typica) was the result of differential predation by birds, the melanic form being more cyptic than typica in industrial areas where the tree bark was darkened by air pollution.
I repeat, nothing you have posted has refuted or in any way invalidated this conclusion.
The theory of preferential predation is sufficient to explain all the observed data - on it's own.
None of the other theories thus far floated have this ability. Not one.
Until there is more evidence or a better explanation is proposed there remains only one ligical valid conclusion currently based on the evidence:
This remains a clear, distinct, and unambiguous demonstration of Natural Selection in action.
Denial does not make this evidence go away nor does it make this conclusion invalid.
Enjoy.
Edited by RAZD, : added line in pink

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This message is a reply to:
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MartinV 
Suspended Member (Idle past 5906 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 219 of 350 (355125)
10-08-2006 5:51 AM
Reply to: Message 216 by RAZD
10-07-2006 8:08 AM


Re: More Ignorance.
RAZD writes:
Because mutation is not directed. There is no choice to be red or blue or green involved and no mechanism to cause this. There is no "chameleon" process where cryptic patterns are chosen {to appear in order} to match backgrounds.
This is a common misconception of evolution mutation & natural selection mechanisms by creationists and it leads to more misunderstanding on their part of how evolution works.
I think that to underestand darwinistic myth of random mutation and natural selection as mechanism behind evolution is not so complicated as one would say. But if some darwinist hold it for some secret wisdom I do not care.
As to "chameleon" process: Once I saw a darwinistic propaganda film on birds catching fish. It was said, that there was once rare mutation, that led to the completely white color of abdomen of a bird and consequently fish could not detect it against the sky, so bird has advantage and its genes spreads.
And that was my question before. I suppose that mutation that can change colour/pattern of moths wings are rare. Anyway I do not see any restriction, why this rare mutation could not change colour of wings to green/yellow color? Or might be, that it changes, but we did not detect them, because they are so rare and do not survive?
Yes?
It seems strange to me, that according darwinians there were more melanic forms of species of Lepidoptera during industrial revolution. Even according Majerus:
However, in other cases, new melanic forms have arisen by mutation and then spread in industrial regions of Britain, despite the existence of melanic forms in other parts of Britain. (Melanism: Evolution in Action, Michael E. N. Majerus, 1998, p198)
Is it not weird, that mutation is somehow restricted to dark color in moths species and green, red, yellow mutations are excluded ? If we do not detect other colours but melanic, is it correct to presume, that mutations in this case of moths are "random"? I would say that mutation in these cases have nothing to do with chance but are rather directed to prevalent color of environment (really some chameleon process as you noted). Otherways there should be some constraints to vivid coluors, but then again - melanic mutation is not random only just somehow predetermine to happen in particular way.
Because we know, that some of night moths have colourful hindwings.
The adults mainly fly at night. They usually feed on nectar from flowers or ripe fruit. Most are dull in colour, but some have colourful hindwings.
For instatnce yellow:
http://www.geocities.com/brisbane_noct/TransverseMoths.htm
So why so many random mutation during industrial revolution have led to melanic forms, but we did not found any random mutation (even before and after) that led to other colors as melanic ones? Were mutations during the period really random? If directed, would not be that case of melanic moths somehow falsify darwinism?

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Wounded King
Member (Idle past 110 days)
Posts: 4149
From: Cincinnati, Ohio, USA
Joined: 04-09-2003


Message 220 of 350 (355143)
10-08-2006 7:52 AM
Reply to: Message 219 by MartinV
10-08-2006 5:51 AM


Re: More Ignorance.
Mutations work on a basis of what is already there, both in terms of traits, molecular pathways and genetic sequences.
The non-melanic form of Biston betularia still have black pigmentation, supposedly as part of their crypsis for lichen. Therefore all that is needed is an expansion of this trait. This is clearly distinct from the generation of a novel trait for a completely distinct colour pigment. Since it is easier to get to a completely black moth from a partially black moth than it is to generate a novel colour pigment that mutation is likely to happen more frequently.
It may well be that more colourful pigments have arisen and been lost from the peppered moth species, but in the absence of anyone having ever observed them this hypothesis is pure fancy.
TTFN,
WK
Edited by Wounded King, : Corrected typo

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Wounded King
Member (Idle past 110 days)
Posts: 4149
From: Cincinnati, Ohio, USA
Joined: 04-09-2003


Message 221 of 350 (355144)
10-08-2006 8:00 AM


I'm not sure if anyone has mentioned this parrallel example before but some species of pocket mice seem to show a similar normal/melanic form of crypsis in line with their natural habitats on normal or dark volcanic rocks (Nachman et al., 2003). They find the genetic basis for the melanic form in one population associated with mutaions in the melanocortin receptor-1 gene but find a distinct basis for melanism in another poulation showing that while the trait is evolved in a parallel fashion its genetic basis is distinct.
Surely if the basis for such traits were pre-determined they would arise in the same way amongst such closely related populations.
TTFN,
WK
Edited by Wounded King, : typographical error

Replies to this message:
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Belfry
Member (Idle past 5163 days)
Posts: 177
From: Ocala, FL
Joined: 11-05-2005


Message 222 of 350 (355145)
10-08-2006 8:11 AM
Reply to: Message 219 by MartinV
10-08-2006 5:51 AM


Re: More Ignorance.
MartinV writes:
So why so many random mutation during industrial revolution have led to melanic forms, but we did not found any random mutation (even before and after) that led to other colors as melanic ones? Were mutations during the period really random? If directed, would not be that case of melanic moths somehow falsify darwinism?
I expect that RAZD will have no trouble answering you, but I'll just put in that it's because variations in melanism are very common among insects (and in other animals, too - as I see WK has already beaten me to pointing out). It's not a matter of mutating to form a novel pigment, or to express it in very different regions of the body or wings. It's mostly a matter of changing the degree of saturation of a pigment that is already produced.
Here's a link to a good article that gives a primer to melanism in insects, as well as what is known about the genetics, at least as of 2003: True, JR. 2003. Insect melanism: the molecules matter. Trends in Ecology and Evolution. 18(2): 640-647. (.pdf)
Edit: Argh, now I see that WK beat me to all of my points. I was too slow to finish my post. But my link is still worth bringing in!
Edited by Belfry, : No reason given.
Edited by Belfry, : No reason given.

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RAZD
Member (Idle past 1482 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 223 of 350 (355173)
10-08-2006 9:54 AM
Reply to: Message 219 by MartinV
10-08-2006 5:51 AM


Avoiding the data again?
As to "chameleon" process: Once I saw a darwinistic propaganda film on birds catching fish. It was said, that there was once rare mutation, that led to the completely white color of abdomen of a bird and consequently fish could not detect it against the sky, so bird has advantage and its genes spreads.
And that was my question before.
What was your question? That random mutations happen and that beneficial ones are selected for (and harmful ones selected against) by natural selection?
Or are you really thinking that mutation happens on demand?
Is it not weird, that mutation is somehow restricted to dark color in moths species and green, red, yellow mutations are excluded ? If we do not detect other colours but melanic, is it correct to presume, that mutations in this case of moths are "random"?
Yes it is correct to conclude that mutations are random, even in these moths.
The other half of the picture is selection -- by survival and reproduction, and that is what this topic is about: the evidence for selection based on the preferential predation of moths by birds due to their different camouflage ability in different environments, and how that has affected their relative population proportions.
If novel mutations alter the appearance of a moth to birds such that it is much more noticable to birds, then it too will be selected for consumption, just as ones that become more visible because the environment changes get selected for consumption.
If a novel mutation alters the appearance of a moth to other moths then it may not be selected for reproduction (or less often selected), but this (and similar aspects) are not tested in this condition of industrial pollution affecting moth populations, because it is about the preferential predation of moths by birds due to their different camouflage ability in different environments, and how that has affected their relative population proportions.
Remember we are already talking about a moth that has been previously selected or adapted for cryptic pattern on lichen covered tree bark, and thus any mutation that makes it less like lichen covered tree bark makes it more vulnerable.
Color fits this category that would be actively selected against, and so any mutations for colors would be selected out of the previous populations before pollution was introduced. Even green would have trouble as you have to be either all green on a leaf or all lichen-like on the bark for the current level of camouflage to protect the individuals.
Melanism doesn't fit this category -- it is just variation in the degree of the already existing colors and patterns.
quote:
mel·a·nism -n.
2. Dark coloration of the skin, hair, fur, or feathers because of a high concentration of melanin.
mel·a·nin -n.
Any of a group of naturally occurring dark pigments, especially the pigment found in skin, hair, fur, and feathers.
Variation in an already occurring pigmentation, a difference in degree and not in kind.
So why so many random mutation during industrial revolution have led to melanic forms, ...
The melanic forms were already pre-existing, they were part of the normal variation in the species in both the Peppered Moth and the Oak Moth. And other insects and animals.
There was no new mutation involved in this effect of industrial pollution on the selection fitness of the moths, not for blue, red, green, yellow, brown or black.
This whole topic is all about natural selection of existing variations and not about mutations introducing variations into the populations.
The data shows preferential selection between two existing varieties due to different fitness in different conditions.
The data shows Natural Selection occurred.
Enjoy.

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This message is a reply to:
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MartinV 
Suspended Member (Idle past 5906 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 224 of 350 (355383)
10-09-2006 12:55 PM
Reply to: Message 221 by Wounded King
10-08-2006 8:00 AM


WoundedKing writes:
I'm not sure if anyone has mentioned this parrallel example before but some species of pocket mice seem to show a similar normal/melanic form of crypsis in line with their natural habitats on normal or dark volcanic rocks
(Nachman et al.,2003)....
So I do not understand it much and will apreciate some explanation:
The fact that the four mutations seen in the melanic Pinacate mice Arg-18 ’ Cys, Arg-109 ’ Trp, Arg-160 ’ Trp, and Gln-233 ’ His) are absent in the melanic mice from Armendaris indicates that a similar dark phenotype has evolved independently on these different lava lows and has done so through different genetic changes, although the gene(s) involved in the Armendaris population have not yet been identified.
I do not understand if Armendaris dark phenotype aroused via using different melanic protein as Pinacate melanics? They do not use same melanic protein?
Or there is only different "cascade" of regulatory path via which the same melanic protein is activated and which in Armendaris population we did not indentify yet?
...local expression of agouti results in decreased synthesis of eumelanin and increased production of pheomelanin. Wild-type laboratory mice have banded hairs on their dorsum; these hairs have a black tip, a middle yellow band, and a black base (the agouti hair). This banding is caused by a pulse of agouti expression during the middle phase of the hair cycle, resulting in deposition of pheomelanin during the middle of hair growth and deposition of eumelanin at the beginning and end of hair growth.
Pheomelanin (yellow and red pigment) is deposit in hair of some morphs. The article claims are backed by surprisingly old sources (8,9,10 are all before 1948) that owls see colors:
The close match between the color of the mice and the color of the substrate on which they live is thought to be an adaptation against predation (8, 9).
Owls are common predators of these mice, and experiments by Dice (10) on deer mice showed that owls can effectively discriminate between light and dark mice even at night. Thus, it is likely that owls exert strong selection on coat color in C. intermedius, and that differences in coat color are an adaptation for crypsis.
This seems not to be taken for granted by latest sources:
Phodopsins containing 6- to 9-membered rings.
The triggering process of visual transduction:
The kinds of Rh differ from organism
to organism: horses, dogs and owls only have rod cells and hence lack color vision, whereas chicken (ref. I), gold fish (ref. 2), gecko (ref. 3), for example, have multiple Rh species and hence should have superb color vision.
(here).
and even if they have:
The retina of an owl's eye has an abundance of light-sensitive, rod- shaped cells appropriatelycalled "rod" cells. Although these cells are very sensitive to light and movement, they do not react well to colour. Cells that do react to colour are called "cone" cells (shaped like a cone), and an Owl's eye possesses few of these, so most Owls see in limited colour or in monochrome.
(here).
but whats more: these cones sometimes contain same photoreceptors as rods!
See:
Cone Pigment of the Great Horned Owl.
(here).
And last but not at least again from your article:
For example, one of the best known cases of adaptation involves color morphs of the peppered moth, Biston betularia. Yet, after more than a half-century of study, the genes responsible for these color differences remain unknown (3).
It would be interesting to know. Now we do not know where peppered moths rest, if there is any connection between available lichen resting places and oscillation of typica population and even we do not know genetics behind peppered moth melanic phenomenon. Yet we are persuaded same as in your link that oscillation of peppered moths is due bird predation.

This message is a reply to:
 Message 221 by Wounded King, posted 10-08-2006 8:00 AM Wounded King has replied

Replies to this message:
 Message 225 by Wounded King, posted 10-09-2006 1:39 PM MartinV has replied
 Message 228 by RAZD, posted 10-09-2006 4:08 PM MartinV has replied

  
Wounded King
Member (Idle past 110 days)
Posts: 4149
From: Cincinnati, Ohio, USA
Joined: 04-09-2003


Message 225 of 350 (355397)
10-09-2006 1:39 PM
Reply to: Message 224 by MartinV
10-09-2006 12:55 PM


I do not understand if Armendaris dark phenotype aroused via using different melanic protein as Pinacate melanics?
Melanic protein is a vague term, there are a number of distinct elements to the generation of melanic colouring, as the article says there are ~80 genes which have been found to have a role in coat colouration. The gene in which the mutations were identified in this paper were not melanic proteins in the sense of being part of a pigment.
Or there is only different "cascade" of regulatory path via which the same melanic protein is activated and which in Armendaris population we did not indentify yet?
This seems the most likely hypothesis since there are a number of levels within such a cascade at which a mutation could act.
The article claims are backed by surprisingly old sources (8,9,10 are all before 1948) that owls see colors
You now seem to be arguing based on the rather random premise that the paper claims that owls see colour, in the sense of RGB presumably given your discourse on rod and cones. The context and the phenotypes makes it clear that the 'colours' being descriminated are the white/black dark/light coat 'colours' which would pose no barrier to descrimination for an animal with monochromatic sight and therefore seems entirely consistent with the cited earlier research. Indeed an 'abundance' of cells 'very sensitive to light and movement' would seem exactly the sort of vision which would select for shades of light or dark relative to the background on which the prey was resting/moving.
Why are ~70 year old experiments surprisingly old? Your own references have frequently been before that time. Why shouldn't experimentalists in the 1930's-40's have been capable of testing for visual accuity of owls for mice? It isn't like they are using it as a reference for genetic sequencing. None of the subsequent research you cite suggests anything contradicting Dice et al.'s research. A (slightly) more recent paper shows similar descriminatory abilities for the detection of white and agouti mice on a variety of backgrounds (Kaufman, 1974).
It would be interesting to know.
It certainly would, the review article on insect melanism which was referenced by Belfry should give you some idea of some of the research being done in that field.
Now we do not know where peppered moths rest, if there is any connection between available lichen resting places and oscillation of typica population and even we do not know genetics behind peppered moth melanic phenomenon. Yet we are persuaded same as in your link that oscillation of peppered moths is due bird predation.
Those who are persuaded are persuaded by the available evidence, it may be that if an environmental change occurs which affects the prevalence of lichen then you would see an effect on the population. That in no way means that the evidence doesn't suggest that in the absence of any such change predation by birds acts to favour melanic forms in more polluted areas and the lighter forms in areas with cleaner air. No one has said that bird predation is the only environmental factor acting to drive selection on these moths, obvioulsy the nature and prevalence of lichens as a substrate for rest would also be important if lichen like crypsis is supposed to be benefiting them.
TTFN,
WK

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