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Author Topic:   "The Edge of Evolution" by Michael Behe
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 19 of 149 (531124)
10-16-2009 8:54 AM
Reply to: Message 5 by Colin
10-14-2009 5:27 PM


Re: Needs more information
Consider the Malarial parasite as a real life case study for evolution. since an anti malarial drug "chloroquine" was first mass produced sometime during WW2, it is thought that malaria developed resistance to the drug about 4 times independently. Behe is happy to call this less than 10, to be safe. All of the known resistant malarial strains have common changes in 2 amino acids, located in a section of DNA which encodes for a protein pump.
Other later drugs, put up much less of a fight, and became ineffective much quicker, sometimes just weeks. These drugs could be overcome by a mutation of just one of several amino acids.
By taking the estimated number of chloroquine resistant strains (10) over the past half century, the approximate number of malarial parasites in each infected host (1 trillion), and the estimated number of infected hosts in the same time 10 million, the chances of malaria developing a resistance to chloroquine is approximately 1 in 10^20.
But the fallacy here seems obvious. The fact that resistance "only" evolved four times is not an indictment of the failure of mutation to produce the necessary alleles, but rather a testament to the efficiency of natural selection in spreading it. Indeed, if the areas where malaria existed were contiguous, and chloroquine was used throughout that area, we might well have expected resistance to have evolved only once.
Indeed, if you think about the random nature of mutations, it is obvious that the mutations in question must have arisen literally millions and millions of times in the past --- they just never got spread by natural selection, because we hadn't invented chloroquine at that point. But once we did, and they were spread by natural selection, they could no longer arise. Because they were already present.
Edited by Dr Adequate, : No reason given.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 5 by Colin, posted 10-14-2009 5:27 PM Colin has not replied

Replies to this message:
 Message 20 by traderdrew, posted 10-16-2009 11:26 AM Dr Adequate has replied
 Message 55 by Kaichos Man, posted 10-20-2009 8:38 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 22 of 149 (531317)
10-17-2009 12:11 AM
Reply to: Message 20 by traderdrew
10-16-2009 11:26 AM


Fallacy
There is no fallacy.
I think there is. Behe is apparently trying to estimate the difficulty or improbability of malaria parasites evolving chloroquine resistance by counting the number of times it happened.
I think my post makes it clear that why that's not a legitimate procedure.
Edited by Dr Adequate, : No reason given.

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 Message 23 by Colin, posted 10-17-2009 4:39 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 24 of 149 (531341)
10-17-2009 6:06 AM
Reply to: Message 23 by Colin
10-17-2009 4:39 AM


Sickle Cell
I had forgotten, but another post reminded me that Behe makes a point about another resistance that has yet to be overcome at all, based on our current knowledge. And that is the sickle gene. Apparently thousands of years old, the trait gives a person resistance to malaria, and to date, malaria has found no solution. This is highlighted by Behe as an example of something evolution cannot seem do (at least yet).
Human malaria itself may be as little as 3000 years old.
You don't say where you got the figure for the age of sickle cell. But I don't actually think it's time that's been the problem for Plasmodium. We know that almost inevitably, to become better adapted to one environment is to become worse adapted to the original environment. And people with the sickle-cell allele are in a minority. It is possible that some parasite, or many of them, have come up with just the right mutations to live in the red blood cells of people with the sickle-cell allele (we may note in this connection that sometimes malaria does successfully infect people with the sickle-cell allele). But it is not at all clear that such a variation would ever be favored by natural selection.
Again considering the vast numbers of malaria available to crunch the numbers, such a case suggests that if a step of similar complexity stood between our ancestors and a particular beneficial mutation, it would not happen.
Any particular beneficial mutation? I suppose not. Evolution produces adaptation, not perfection. I guess that's why we're not all immune to all diseases. And why all diseases aren't able to overcome all our mechanisms of immunity. Oh look, evolution fails twice!
Meanwhile, that ol' Intelligent Designer is so smart that all of his creations are perfect. I wonder why we never see any of 'em.
Again, the obsession with malaria here, is that it is a real example of evolution causing an organism to adapt to its environment, and the efficiency at which it does so.
And, fortuitously, a case where it would be downright immoral to perform pretty much any relevant experiment one can think of.
Edited by Dr Adequate, : No reason given.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 27 of 149 (531345)
10-17-2009 7:05 AM
Reply to: Message 26 by Dr Jack
10-17-2009 6:57 AM


Re: Sickle cell vs. antimalarials
* - in fact, the resistance of Sickle Cell heterozygotes to Plasmodium may not be disadvantageous to the parasite at all. Often reduced mortality among hosts is of benefit to parasites.
Yes, but surely in this case it's not just reduced mortality, it's reduced probability of becoming infected in the first place. Apart from that, good points.

This message is a reply to:
 Message 26 by Dr Jack, posted 10-17-2009 6:57 AM Dr Jack has replied

Replies to this message:
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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 31 of 149 (531396)
10-17-2009 2:51 PM
Reply to: Message 30 by bluegenes
10-17-2009 9:05 AM


Re: Joe Thornton (and creationist targets).
Or to put it another way, Behe is trying to use a (flawed) a posteriori estimate of how long it took some particular feature in some species to evolve --- to come to an a priori estimate of how long it should have taken some particular species to be what it is.
No, his reasoning just doesn't fit together, does it?
Edited by Dr Adequate, : No reason given.

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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 35 of 149 (531473)
10-18-2009 6:48 AM
Reply to: Message 33 by Colin
10-18-2009 1:31 AM


Re: What Behe's calculations actually mean for human evolution
Since the number of potential evolutionary paths is unknown, let me work backwards. Behe puts the probability of chloroquine resistance at 1 in 10^20.
You see where I proved that his reasoning was droolingly hopelessly wrong?
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 33 by Colin, posted 10-18-2009 1:31 AM Colin has replied

Replies to this message:
 Message 37 by Colin, posted 10-18-2009 7:27 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 44 of 149 (531588)
10-19-2009 12:25 AM
Reply to: Message 37 by Colin
10-18-2009 7:27 AM


Re: What Behe's calculations actually mean for human evolution
Ive just been rereading your posts. Have you read the first part of message 23, and does this apply to the argument you made about Behe's probability argument? If not, could you remind me.
I did read it. I didn't follow it: I didn't quite see what point you were trying to make. But then you finished it up by saying: "Will have to do some research and come back to this."
So I was waiting for you to do that. It seems unnecessary for me (and unfair on you) for me to start asking you what you're getting at when you're still trying to figure that out yourself.
So far as we've got, Behe's point seems simply asinine. He's trying to calculate the probability of an evolutionary event by taking the number of times it's happened and dividing by the population size --- but this ignores the existence of natural selection. It's almost as though I were to argue that the fact of my being born is very unlikely because in all my life I've only been born once. Well of course I have. That's how it works.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 37 by Colin, posted 10-18-2009 7:27 AM Colin has replied

Replies to this message:
 Message 47 by Colin, posted 10-19-2009 3:27 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 49 of 149 (531609)
10-19-2009 4:27 AM
Reply to: Message 47 by Colin
10-19-2009 3:27 AM


Re: What Behe's calculations actually mean for human evolution
I still believe that reading between the lines, he would have taken the things we spoke about into account when calculating the probability.
The things between the lines are not evidence.
I myself would never "read between the lines", but if I did I wouldn't do so and conclude that Behe was probably right. The man has a track record. It is not impressive.
You also seem to disagree in a general sense with this line of reasoning because it involves a specific.
Yes, the "Texas Sharpshooter Fallacy". But my point would be broader than that.
If humans were absolutely perfect, then your analogy of winning the lottery would be correct. But we're not. We're capable of surviving, but we're a bit of a mess. Our immune systems screw up. Our bodies screw up. Our brains screw up.
You brought up sickle-cell anemia. Apparently the best defense we have against malaria is such that we die of possessing that defense if we have that allele in homozygotic form. Which leads me to say: "Intelligent design, my ass".
What we can say is that we're better adapted to survive than other hypothetical organisms we can think of. But we have no reason to suppose that evolution must have gotten it right every time, because clearly it didn't. It doesn't. It can't.
Let us compare this situation with our expectations should we have been specially created by a perfect and omniscient God ...
Edited by Dr Adequate, : No reason given.
Edited by Dr Adequate, : No reason given.

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 Message 47 by Colin, posted 10-19-2009 3:27 AM Colin has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 63 of 149 (532082)
10-21-2009 8:23 AM
Reply to: Message 55 by Kaichos Man
10-20-2009 8:38 PM


Re: Needs more information
Having pronounced this to be clear evidence that Irreducible Complexity has been overcome and genetic information increased, he then deftly shoots himself in the foot by pointing out that the extreme rarity of the double-mutant suggests two simultaneous mutations.
I have the book in front of me. He says no such thing.

This message is a reply to:
 Message 55 by Kaichos Man, posted 10-20-2009 8:38 PM Kaichos Man has replied

Replies to this message:
 Message 66 by Kaichos Man, posted 10-21-2009 8:56 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 65 of 149 (532084)
10-21-2009 8:25 AM
Reply to: Message 57 by Kaichos Man
10-20-2009 11:52 PM


Re: Joe Thornton
So now we have this new element. The current theory appears to be: "Random mutation, followed by the fortuitous assembly of necessarily complex genetic structures courtesy of some very convenient neutral mutations, followed by natural selection."
Hard to believe it's all the work of a process that has no purpose or target, isn't it?
In fact, it's impossible to believe.
That's probably why the passage that you have presented in quotes is not actually a quotation from anyone other than you.

This message is a reply to:
 Message 57 by Kaichos Man, posted 10-20-2009 11:52 PM Kaichos Man has replied

Replies to this message:
 Message 67 by Kaichos Man, posted 10-21-2009 8:57 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 71 of 149 (532108)
10-21-2009 10:41 AM
Reply to: Message 66 by Kaichos Man
10-21-2009 8:56 AM


Re: Needs more information
You notice how the passage you have quoted in no way supports your false and ridiculous claim?

This message is a reply to:
 Message 66 by Kaichos Man, posted 10-21-2009 8:56 AM Kaichos Man has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 72 of 149 (532110)
10-21-2009 10:48 AM
Reply to: Message 67 by Kaichos Man
10-21-2009 8:57 AM


Re: Joe Thornton
Did I suggest otherwise?
You were indeed suggesting that you were presenting the opinions of others, rather than some crazy nonsense that you'd made up in your head.

This message is a reply to:
 Message 67 by Kaichos Man, posted 10-21-2009 8:57 AM Kaichos Man has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 73 of 149 (532115)
10-21-2009 10:59 AM
Reply to: Message 68 by Kaichos Man
10-21-2009 9:04 AM


Re: Joe Thornton
But it wouldn't be considered evidence in any other field of science, would it? Unrepeatable, unfalsifiable storytelling.
Perhaps you could keep your absurd falsehoods at least vaguely on topic. If you wish to be wrong about the scientific method instead (and I can see why you'd want to stop discussing genetics) then that would be a topic for another thread.

This message is a reply to:
 Message 68 by Kaichos Man, posted 10-21-2009 9:04 AM Kaichos Man has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 75 of 149 (532210)
10-22-2009 3:02 AM
Reply to: Message 74 by Colin
10-21-2009 11:46 PM


Re: Meaning of the Calculations
I left the value of possible beneficial mutations until last, because it is the hardest value to estimate. Your right, I do not know what this value is, I can only guestimate at best.
Well then.
From the evidence before me, I think that large-scale evolution (such as archosaurs to birds) has in fact happened.
You wish to "guestimate" that despite all the evidence that such events have happened, nonetheless it can't have happened on genetic grounds. But you confess that you find this hard to estimate, and that you are merely "guestimating".
At this point I would suggest that so far my appeals to reality which suggest that such a thing has happened kind of outweigh your "guestimations" that it can't have happened.

This message is a reply to:
 Message 74 by Colin, posted 10-21-2009 11:46 PM Colin has replied

Replies to this message:
 Message 76 by Colin, posted 10-22-2009 4:31 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 78 of 149 (532310)
10-22-2009 4:06 PM
Reply to: Message 76 by Colin
10-22-2009 4:31 AM


Re: Meaning of the Calculations
Without guestimates, we would still be staring blankly out of our caves wondering what to do next. Not having an exact answer for something is a part of life. At least for those of us who don't know everything.
Ah yes, I was forgetting. When creationists make something up to prove their dogma, that is a sign of their deep humility in the face of a universe that they find all but incomprehensible.
And "All the evidence" as you put it is another story.
It is indeed. Even a creationist can see that evolution has happened. So he will make stuff up (or "guestimate", as you put it) to prove that it can't have happened. And that'll make him feel better.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 76 by Colin, posted 10-22-2009 4:31 AM Colin has replied

Replies to this message:
 Message 79 by Colin, posted 10-23-2009 2:13 AM Dr Adequate has replied

  
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