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Author Topic:   Peppered Moths and Natural Selection
crashfrog
Inactive Member


(1)
Message 332 of 350 (670813)
08-19-2012 2:58 PM
Reply to: Message 325 by Big_Al35
08-19-2012 10:02 AM


Classic evolutionary tautology.

Tautologies are, by definition, true.


This message is a reply to:
 Message 325 by Big_Al35, posted 08-19-2012 10:02 AM Big_Al35 has not yet responded

  
Big_Al35
Member (Idle past 348 days)
Posts: 384
Joined: 06-02-2010


Message 333 of 350 (670829)
08-20-2012 4:21 AM
Reply to: Message 320 by Percy
08-17-2012 6:03 PM


Percy writes:

You are correct that some parts of the genetic code *are* protected against natural selection (but not against mutation), but recessive alleles are not an example of this. A better example would be disabled genes that cannot be selected for or against because are not expressed, but the disabled gene is understood to be yet another mechanism of evolution, through further mutation and eventual re-enabling.

Actually, now that we covered the fact that some traits are offered a degree of protection from extinction by being recessive, maybe someone ought to cover why large chunks of dna, particularly the genes, are largely protected from mutation events.


This message is a reply to:
 Message 320 by Percy, posted 08-17-2012 6:03 PM Percy has responded

Replies to this message:
 Message 334 by Dr Adequate, posted 08-20-2012 5:11 AM Big_Al35 has not yet responded
 Message 335 by RAZD, posted 08-20-2012 6:44 AM Big_Al35 has not yet responded
 Message 337 by Percy, posted 08-20-2012 8:16 AM Big_Al35 has not yet responded

    
Dr Adequate
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Posts: 16056
Joined: 07-20-2006
Member Rating: 3.2


Message 334 of 350 (670830)
08-20-2012 5:11 AM
Reply to: Message 333 by Big_Al35
08-20-2012 4:21 AM


Actually, now that we covered the fact that some traits are offered a degree of protection from extinction by being recessive ...

"A degree of protection" is a bit ambiguous: they'll still go extinct, it just takes longer.


This message is a reply to:
 Message 333 by Big_Al35, posted 08-20-2012 4:21 AM Big_Al35 has not yet responded

  
RAZD
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Posts: 19687
From: the other end of the sidewalk
Joined: 03-14-2004
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Message 335 of 350 (670831)
08-20-2012 6:44 AM
Reply to: Message 333 by Big_Al35
08-20-2012 4:21 AM


a few more new topic ideas
Hi again Big_Al35,

Actually, now that we covered the fact that some traits are offered a degree of protection from extinction ...

What we've covered is that during an ecological change of short duration there is an observable shift in the frequency of hereditary traits to adapt to the new challenges and opportunities presented by the change.

Initially this change is not enough to eliminate the less fit camouflage from the gene pool, so when the ecology shifts back the previous (Mendelian) pattern can also reappear.

This change is likely to be along an exponential curve as time passes (nature loves exponential curves it seems, almost as much as beetles ... ), so the longer the change persists the more likely the less fit camouflage will not be able to survive to breed and be culled from the gene pool.

... by being recessive, ...

You still need to understand the difference between change in DNA through mutation, with subsequent dispersal in the gene pool, and gene mixing of existing traits via Mendelian mechanisms. It isn't always the recessive gene that is being repressed in the changing ecology.

A recessive gene may have some protection and it may not -- that depends on the degree of selection pressure and the length of time involved (the exponential curve would be drawn out a little longer before the trait is culled).

A new topic on natural selection and new mutations vs Mendelian gene mixing might help.

There is also the issue of how a recessive gene becomes a dominant gene in the gene pool and whether a new mutation is dominant or recessive (or just neutral), that could be discussed on that new topic: it should be fairly simple to understand that if a change in the ecology suppresses and then culls the dominant gene, that the recessive gene becomes the dominant gene, then a new mutation, that starts out neutral can become expressed and be recessive in a new ecology that over time this pattern will result in permanent changes to the mixture of traits available in the gene pool and the existing population can have an entirely different set of genes from the ancestors.

Maybe I'll work on one for you if you are interested.

.... maybe someone ought to cover why large chunks of dna, particularly the genes, are largely protected from mutation events.

Another great idea for a new topic.

Enjoy.

Edited by RAZD, : added


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This message is a reply to:
 Message 333 by Big_Al35, posted 08-20-2012 4:21 AM Big_Al35 has not yet responded

  
Percy
Member
Posts: 17892
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.2


Message 336 of 350 (670839)
08-20-2012 8:12 AM
Reply to: Message 327 by Big_Al35
08-19-2012 10:22 AM


Big_Al35 writes:

Two or more types of moth (namely dark and light existed prior to the event ie industrialization) and two or more types existed after the event. It was simply a case of which type of moth flourished when.
Therefore I wouldn't view this is as an example of evolution. Others might disagree.

Most here wouldn't use this as an example of full-blown evolution either. You could use it as an example of micro-evolution, but the peppered moth is usually presented as an example of natural selection.

You and some others here have introduced mutation into the equation. This may account for genuine micro-evolution but has nothing to do with the example I was discussing.

A parenthesized "but not against mutation" is not introducing mutation into the equation.

Where are you going with this, Al? What are you trying to say about the peppered moth example of natural selection?

--Percy

Edited by Percy, : Fix quote of self.


This message is a reply to:
 Message 327 by Big_Al35, posted 08-19-2012 10:22 AM Big_Al35 has not yet responded

    
Percy
Member
Posts: 17892
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.2


(1)
Message 337 of 350 (670840)
08-20-2012 8:16 AM
Reply to: Message 333 by Big_Al35
08-20-2012 4:21 AM


Big_Al35 writes:

Actually, now that we covered the fact that some traits are offered a degree of protection from extinction by being recessive, maybe someone ought to cover why large chunks of dna, particularly the genes, are largely protected from mutation events.

What on Earth has this to do with the peppered moth?

--Percy


This message is a reply to:
 Message 333 by Big_Al35, posted 08-20-2012 4:21 AM Big_Al35 has not yet responded

    
barnes
Junior Member (Idle past 2188 days)
Posts: 19
Joined: 08-20-2012


Message 338 of 350 (670889)
08-20-2012 6:31 PM


Evolution activity
Im sure we can all agree life is more complex than a 350 Chevy engine. My proposal to the evolutionist, take a 350 Chevy put it on an engine dino run it up to peak performance rpm and rebuild it in to a Duramax diesel the hole time never missing a beat. You boys get that one done and we can talk.
Replies to this message:
 Message 339 by jar, posted 08-20-2012 6:35 PM barnes has not yet responded
 Message 340 by RAZD, posted 08-20-2012 11:58 PM barnes has not yet responded
 Message 341 by dwise1, posted 08-21-2012 2:00 AM barnes has not yet responded

    
jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004
Member Rating: 1.3


Message 339 of 350 (670890)
08-20-2012 6:35 PM
Reply to: Message 338 by barnes
08-20-2012 6:31 PM


Re: Evolution activity
Seems you posted this once before.

What does it have to do with Peppered Moths or Natural Selection?


Anyone so limited that they can only spell a word one way is severely handicapped!

This message is a reply to:
 Message 338 by barnes, posted 08-20-2012 6:31 PM barnes has not yet responded

  
RAZD
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Posts: 19687
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 2.8


Message 340 of 350 (670910)
08-20-2012 11:58 PM
Reply to: Message 338 by barnes
08-20-2012 6:31 PM


non sequitur post not on topic
Hi barnes and welcome to the fray,

Im sure we can all agree life is more complex than a 350 Chevy engine ...

One of the things this forum likes to do is confine threads to specific topics, in this case the role that natural selection plays in the changes observed in the peppered moth populations.

... and rebuild it in to a Duramax diesel the hole time never missing a beat. You boys get that one done and we can talk

A variation on the old airplane in a junkyard PRATT (point refuted a thousand times).

Why don't you start a new thread on just this little concept, and we will be glad to show you what is wrong with it. It is off topic on this thread.

Go to Proposed New Topics to post new topics, if you are serious about discussing it, or just post it in Coffee House if you want to see what happens.

Enjoy.

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we are limited in our ability to understand
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This message is a reply to:
 Message 338 by barnes, posted 08-20-2012 6:31 PM barnes has not yet responded

  
dwise1
Member
Posts: 3192
Joined: 05-02-2006
Member Rating: 3.8


(1)
Message 341 of 350 (670912)
08-21-2012 2:00 AM
Reply to: Message 338 by barnes
08-20-2012 6:31 PM


Re: Evolution activity
Mike? Is that you? The "real Mike Barnes"? What were you in 1990, SK2 or SK1?

Is your "impossible question" and challenge supposed to be akin to the problem of evolving a four-chambered heart from a three-chambered job? After all, you would argue that while converting the 3-chambered model to the 4, the whole thing would have be shut down, right?

Well, crocodiles do it all the time. They're born with three-chambered hearts and as they grow larger to where they need more efficient oxygen transport which requires a more efficient circulatory system, they switch from three chambers to four without skipping a heart-beat.

You see, a three-chambered heart has two atria and one ventricle, whereas a four-chambered heart has the same two atria and two ventricles. The only physical difference between the two is a muscular septum that separates the ventricle into two chambers. In a three-chambered heart, the oxygenated blood from the lungs gets intermixed with the de-oxygenated blood from the body, which is good enough for an animal with a low metabolism, such as amphibians and most reptiles. But in a three-chambered heart, there is not such intermixing, so the body gets the oxygenated blood from the lungs.

You see, Mike, the secret to coming up with a valid analogy is for the processes involved to be the same or very close to the same. Your engine "analogy" is a false analogy which has nothing to do with how evolution works.

Here's the key to creating a valid analogy: evolution is the result of life doing what life does, so your analogy needs to emulate what life does. Car engines do not fit that bill.


This message is a reply to:
 Message 338 by barnes, posted 08-20-2012 6:31 PM barnes has not yet responded

Replies to this message:
 Message 342 by RAZD, posted 08-21-2012 5:14 AM dwise1 has not yet responded

    
RAZD
Member
Posts: 19687
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 2.8


Message 342 of 350 (670921)
08-21-2012 5:14 AM
Reply to: Message 341 by dwise1
08-21-2012 2:00 AM


another great new topic - more off-topic drift.
Hi dwise1

Is your "impossible question" and challenge supposed to be akin to the problem of evolving a four-chambered heart from a three-chambered job? After all, you would argue that while converting the 3-chambered model to the 4, the whole thing would have be shut down, right?

Great idea for a new topic. Maybe you and barnes can get together on that.

Certainly not about peppered moths.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
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This message is a reply to:
 Message 341 by dwise1, posted 08-21-2012 2:00 AM dwise1 has not yet responded

  
Big_Al35
Member (Idle past 348 days)
Posts: 384
Joined: 06-02-2010


Message 343 of 350 (670958)
08-21-2012 10:30 AM


Percy writes:

Where are you going with this, Al? What are you trying to say about the peppered moth example of natural selection?

I think everything that needed to be said has been said. Glad to see this has been thrown into summary mode so we can all move on.


    
NoNukes
Inactive Member


(2)
Message 344 of 350 (670960)
08-21-2012 11:05 AM


Summation. Topic was never about speciation.
From the original post

And thus we see agreement that this example is about the Natural Selection part of evolution, and not about speciation, and further that it cannot be about speciation because it is talking about the relative size of populations of two varieties of the same species of moth.

Hopefully the conclusions won't all be about Big_Al's last couple of posts. I thought RAZD did a great job of outlining the myths about the peppered moths and debunking the creationist take on what was actually observed. Of course that was accomplished about 6 or so years ago.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

The apathy of the people is enough to make every statue leap from its pedestal and hasten the resurrection of the dead. William Lloyd Garrison.

Choose silence of all virtues, for by it you hear other men's imperfections, and conceal your own. George Bernard Shaw


  
Dr Adequate
Member
Posts: 16056
Joined: 07-20-2006
Member Rating: 3.2


(2)
Message 345 of 350 (670972)
08-21-2012 12:00 PM


Summation
I have written before about the absence of a creationist world-view. Their nonsense about peppered moths is a case in point. It is one of their rituals to recite that they "don't deny microevolution". But they do in fact deny it in every particular case. They lie about peppered moths, they lie about fruit flies, they lie about antibiotic resistance in bacteria, they lie about Lenski's experiments: you show them any example of microevolution and they will in fact deny it.

In the case of peppered moths, it has been observed that natural selection prefers one allele over another. This is plainly, obviously true --- and what's more, this fact would not bring the whole Book of Genesis tumbling down. But they still find the need to lie about it.

I really don't know why. I can observe the phenomenon of creationist behavior, but I can't explain it.


  
RAZD
Member
Posts: 19687
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 2.8


Message 346 of 350 (671044)
08-21-2012 8:00 PM


Summation
It's very simple: read Message 1.

If you have trouble with differentiating natural selection from the rest of evolution (mutation, speciation etc), look at Message 331 to see the specific role that selection plays in the evolutionary processes.

Failing that, start a new thread concerning what you don't understand.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

  
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