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Author Topic:   "The Edge of Evolution" by Michael Behe
Colin
Junior Member (Idle past 3326 days)
Posts: 27
From: Adelaide, Australia.
Joined: 10-14-2009


Message 1 of 149 (530545)
10-14-2009 3:05 AM


I found "The Edge of Evolution" to contain rigorous arguments to show why Darwinian evolution is not the means by which species were created. His main argument draws on our knowledge gained from the fight between humans and malaria. I found this book to be carefully and thoughtfully written, and particularly like the way his arguments rely heavily on calculations performed on the available data. I have been unable to find any counter argument, so I have begun this discussion.
Replies to this message:
 Message 9 by Coyote, posted 10-14-2009 8:23 PM Colin has responded

    
Adminnemooseus
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Message 2 of 149 (530547)
10-14-2009 3:11 AM


Needs more information
His main argument draws on our knowledge gained from the fight between humans and malaria.

You need to expand on this some before we're to an adequate starting point for a debate.

Please post more information as a new message in this topic.

Adminnemooseus


    
Colin
Junior Member (Idle past 3326 days)
Posts: 27
From: Adelaide, Australia.
Joined: 10-14-2009


Message 3 of 149 (530551)
10-14-2009 3:26 AM


Re: Needs more information
Okay no problem, I will write a summary of the main points this week and get back to you.

Thanks, Colin.


    
Adminnemooseus
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Message 4 of 149 (530563)
10-14-2009 3:59 AM


Re: Needs more information
I guess I should have said this in the previous message.

We're not looking for a huge amount of text - Indeed, we don't want a huge amount of text in an opening message.

About 2 or 3 modest paragraphs should do it. We just need a beginnings of Behe's core theme to get things started.

Adminnemooseus


    
Colin
Junior Member (Idle past 3326 days)
Posts: 27
From: Adelaide, Australia.
Joined: 10-14-2009


Message 5 of 149 (530741)
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.

Malaria has not yet managed to overcome the problem of the sickle gene in humans, despite having a much longer time to work with than with the drug chloroquine.

Keeping in mind that only 2 essential amino acid changes were required, if 4 were needed for example, that number would be 1 in 10^40, which he says is less than the estimated total number of bacteria that have ever lived on Earth.

Now, the total number of humans to have ever lived is easily less than
10^20 (even generously allowing for unknown ups and downs in population). How then, if the mind boggling numbers of malaria take so long to overcome a problem requiring just 2 changes in amino acids, can the piddling number of humans be expected to have achieved a transition from ape-like creatures with less population? (for example)

Edited by Colin, : No reason given.

Edited by Colin, : No reason given.


Replies to this message:
 Message 7 by bluegenes, posted 10-14-2009 7:23 PM Colin has responded
 Message 12 by Modulous, posted 10-14-2009 9:18 PM Colin has responded
 Message 19 by Dr Adequate, posted 10-16-2009 8:54 AM Colin has not yet responded

    
AdminNosy
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Message 6 of 149 (530757)
10-14-2009 6:36 PM


Thread Copied from Proposed New Topics Forum
Thread copied here from the "The Edge of Evolution" by Michael Behe thread in the Proposed New Topics forum.
  
bluegenes
Member (Idle past 558 days)
Posts: 3119
From: U.K.
Joined: 01-24-2007


(1)
Message 7 of 149 (530768)
10-14-2009 7:23 PM
Reply to: Message 5 by Colin
10-14-2009 5:27 PM


Targets are for creationists.
Colin writes:

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.

In the two step resistance that Behe is referring to, the first single mutation does actually confer some resistance to chloroquine, and is therefore selected for.

Colin writes:

Keeping in mind that only 2 essential amino acid changes were required, if 4 were needed for example, that number would be 1 in 10^40, which he says is less than the estimated total number of bacteria that have ever lived on Earth.

Plasmodium can do four in developing resistance to pyrimethamine, so you're wrong. Again, the stages are beneficial, and are selected for.

PNAS: Stepwise acquisition of pyrimethamine resistance in the malaria parasite

There are a lot more technical comments that could be made, but first I want to point out something that's basically wrong in Behe's way of thinking.

Evolution doesn't have to hit targets. It's not heading anywhere.

If there were a rare specific potentially beneficial series of mutations that might confer some great advantage on humans, but that would only occur once in a billion years on average, it's extremely unlikely that we will get it in the next million years. However, if there are 10 million such rare beneficial series that could occur, one will be completed every century in an individual, and the population would receive 10,000 on average each million years.

I.D. Creationists frequently make the mistake of making spurious probability estimates that include their own view of design and direction in the system. Give evolution a specific target, a certain pre-described series of mutations, and it's always unlikely to hit it, and it doesn't need to.


This message is a reply to:
 Message 5 by Colin, posted 10-14-2009 5:27 PM Colin has responded

Replies to this message:
 Message 8 by Colin, posted 10-14-2009 8:19 PM bluegenes has responded

  
Colin
Junior Member (Idle past 3326 days)
Posts: 27
From: Adelaide, Australia.
Joined: 10-14-2009


Message 8 of 149 (530782)
10-14-2009 8:19 PM
Reply to: Message 7 by bluegenes
10-14-2009 7:23 PM


Re: Targets are for creationists.
Hi, thanks for replying!

You are correct about the 1 protein change conferring a partial resistance, and I have no reason to doubt you about the plasmodium achieving 4, but neither of these effect the argument because the amino acid changes do not feature in the calculations. It serves only to better understand the changes taking place, and perhaps rule out the possibility of the changes requiring a major overhaul of the organism.

The probability calculations are taken directly from observable outcomes. Namely, population levels and frequency of resistant strains. The four hypothetical changes i proposed are specific to this example, and are in light of the probability calculated from observed occurrences. Other cases could of course achieve larger changes for reasons such as having more possible changes to choose from (as you suggest). I stress that the calculations are not reliant on the number of changes taking place. For example, say there are many more sets of possible changes malaria had to choose from. we would expect this to alter the observed instances of resistance developing.

Getting back to the real life example. Malaria was free to find all and any possible changes to gain resistance, and at the end of the day we judge its ability to do so based on observed facts.

Lastly, for Malaria this is a case of extreme selective pressure. A do or die situation. Not a general search for some advantage. Therefore it is not unreasonable to use this as a demonstration of how evolution acts to develop a species and overcome hurdles (I realize evolution does not "care" about hurdles - never the less this is what it does). If we deny ourselves permission to suggest evolution has any direction or trend from which to make predictions, It becomes a fit-all theory, with all the consistency of a piece of play dough.


This message is a reply to:
 Message 7 by bluegenes, posted 10-14-2009 7:23 PM bluegenes has responded

Replies to this message:
 Message 14 by bluegenes, posted 10-15-2009 5:57 AM Colin has responded

    
Coyote
Member (Idle past 187 days)
Posts: 6117
Joined: 01-12-2008


(1)
Message 9 of 149 (530783)
10-14-2009 8:23 PM
Reply to: Message 1 by Colin
10-14-2009 3:05 AM


There are calculations, and there are calculations...
I found this book to be carefully and thoughtfully written, and particularly like the way his arguments rely heavily on calculations performed on the available data. I have been unable to find any counter argument, so I have begun this discussion.

The following example does not deal with malaria, but it does deal with the way genetic networks operate, and it does show that these systems are robust: there are indeed many solutions to a given problem.

Based on studies such as this, there seems to be no biological justification for deliberately misrepresenting biology, as creationists are wont to do, and then using that misrepresentation to mathematically "stack the deck" against evolution. It may be good religion and good mathematics, but the evidence is showing that it is neither good biology nor good science.

Making Genetic Networks Operate Robustly: Unintelligent Non-design Suffices, by Professor Garrett Odell (online lecture):

http://www.researchchannel.org/prog/displayevent.aspx?rID...

Description: Mathematical computer models of two ancient and famous genetic networks act early in embryos of many different species to determine the body plan. Models revealed these networks to be astonishingly robust, despite their 'unintelligent design.' This examines the use of mathematical models to shed light on how biological, pattern-forming gene networks operate and how thoughtless, haphazard, non-design produces networks whose robustness seems inspired, begging the question what else unintelligent non-design might be capable of.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
This message is a reply to:
 Message 1 by Colin, posted 10-14-2009 3:05 AM Colin has responded

Replies to this message:
 Message 10 by Colin, posted 10-14-2009 8:32 PM Coyote has responded

  
Colin
Junior Member (Idle past 3326 days)
Posts: 27
From: Adelaide, Australia.
Joined: 10-14-2009


Message 10 of 149 (530785)
10-14-2009 8:32 PM
Reply to: Message 9 by Coyote
10-14-2009 8:23 PM


Re: There are calculations, and there are calculations...
As i mentioned in the last post (only posted literally 1 min ago - you probably missed it), Malaria was open to all possible solutions, yet took many trillions of organisms to find it. Even then, the solutions found always included the same two common changes, suggesting that any other possible solutions are even harder to find.
This message is a reply to:
 Message 9 by Coyote, posted 10-14-2009 8:23 PM Coyote has responded

Replies to this message:
 Message 11 by Coyote, posted 10-14-2009 8:57 PM Colin has responded

    
Coyote
Member (Idle past 187 days)
Posts: 6117
Joined: 01-12-2008


(1)
Message 11 of 149 (530790)
10-14-2009 8:57 PM
Reply to: Message 10 by Colin
10-14-2009 8:32 PM


Re: There are calculations, and there are calculations...
As i mentioned in the last post (only posted literally 1 min ago - you probably missed it), Malaria was open to all possible solutions, yet took many trillions of organisms to find it. Even then, the solutions found always included the same two common changes, suggesting that any other possible solutions are even harder to find.

How do you reconcile that with the data in the on-line lecture I posted?

That mathematical model seems to suggest that genetic networks are far more robust than most scientists, and certainly all creationists, have been aware of. And it suggests that there are multiple pathways to a given solution.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
This message is a reply to:
 Message 10 by Colin, posted 10-14-2009 8:32 PM Colin has responded

Replies to this message:
 Message 13 by Colin, posted 10-15-2009 3:54 AM Coyote has not yet responded

  
Modulous
Member (Idle past 185 days)
Posts: 7789
From: Manchester, UK
Joined: 05-01-2005


(1)
Message 12 of 149 (530792)
10-14-2009 9:18 PM
Reply to: Message 5 by Colin
10-14-2009 5:27 PM


What Behe's calculations actually mean for human evolution
How then, if the mind boggling numbers of malaria take so long to overcome a problem requiring just 2 changes in amino acids, can the piddling number of humans be expected to have achieved a transition from ape-like creatures with less population? (for example)

Behe does have some problems with facts specifically frequently getting them wrong - including in that very book. But for the moment, let's take the numbers as agreed upon.

You are citing a specific and then asking about a general. If you had hypothetically asked six million years ago - what is the probability that human ancestors would evolve into humans, the answer would have been low. Just as it is low that any given lottery ticket will win the jackpot.

But if you were asking 'what is the probability that these creatures would significantly evolve over the next six million years' the answer would be much higher (still quite low I'd imagine - there is a chance that relative stasis could occur and there is an even greater chance that extinction would occur before six million years was up).

However, let us suggest that there have been 36billion homo sapiens. Each one of which has 100 unique mutations. Then between us all there are Three and half billion mutations to go around. There are only about three billion base pairs to mutate. Granted - there are factors that would mean there would be repeat mutations so the assumption that mutations are 'unique' is very suspect, but we are only talking about homo sapiens - so we're only looking a few tens of thousands of years here (though obviously a sizeable chunk of those has been more recently). It is also a conservative figure - and some estimates suggest that 36billion was achieved before the Roman Empire.

Here is a a source that discusses the difficulties and ideas behind all of these kinds of estimates.

Let us say 5billion births per 50,000 years and stay conservative. There are 500 50,000 year periods in 5 million years. So let's say 500 x 5billion births since human/chimps common ancestor. That's 2,500,000,000,000 births each with about 100 mutations making for 250,000,000,000,000 genetic mutations. And this doesn't take into account major events such as chromosome splits and the like.

With all those changes going on - and the possible effects of frame shifting and the like. We'd anticipate that unless there was a strong selective pressure to remain very similar - a great deal of change is possible.

If there is a selective pressure to change - then we'd expect either extinction (very strong selective pressure) or a change towards a solution. Malaria has an advantage that humans don't - sheer numbers. Therefore it can, as a species, survive much much greater selection pressures than primates could.

If humanity had the kind of selection pressure malaria faced - an increasing chance of dying unless two specific amino acid changes exist (assuming that only those two amino acid changes would suffice) then there is a good chance we'd simply go extinct - even if some people were 'lucky' enough to have those mutations.

The evidence does suggest that our lineage faced a tremendous selective pressure (since most of our brethren are extinct - and many today are on the brink of it). It probably wasn't so severe as the idea that only a small set of mutations will mean survival (which is all Behe's probability calculation really proves if it proves anything) - but severe enough to mean that prospering would require some changes. Different changes occurred - many species died out and a few survived.

Our ancestors were fully functioning and successful survivors. There was, however, limited resources and most births would result in death before adulthood. Any advantage that genetics could convey would be likely to increase in frequency if the species could survive long enough. It might be that a mutation in the adrenaline pathway causes them to become less hostile and more hidden away so they tend to compete with other primates less. It might be a mutation that allows them a bit more of an advantage in a different niche where the competition for resources is less.

There might be many solutions, and a species may never come upon one and instead go extinct. Some species do change sufficiently enough to continue to compete for the resources.

So yeah - Behe has essentially told us something we could have deduced in other ways: our selection pressure wasn't so great as malaria faced.


Note: It's late and my maths is likely wrong, but it's back of the envelope stuff for illustration only. I don't intend to mislead


This message is a reply to:
 Message 5 by Colin, posted 10-14-2009 5:27 PM Colin has responded

Replies to this message:
 Message 15 by Colin, posted 10-15-2009 5:33 PM Modulous has acknowledged this reply
 Message 16 by Colin, posted 10-16-2009 5:01 AM Modulous has responded

  
Colin
Junior Member (Idle past 3326 days)
Posts: 27
From: Adelaide, Australia.
Joined: 10-14-2009


Message 13 of 149 (530810)
10-15-2009 3:54 AM
Reply to: Message 11 by Coyote
10-14-2009 8:57 PM


Re: There are calculations, and there are calculations...
A friend of mine who does research into leukemia was talking about the robustness of cells sometime ago, but in favor of creation. I watched most of this video but i must have missed how it shows many solutions to evolutionary pathways are available. Perhaps you can summarize the calculations you are referring to. The calculations I referred to from Behe are from observed events, not simulations. There is not a lot of room to move. X number of malarial cells, Y number of solutions.
This message is a reply to:
 Message 11 by Coyote, posted 10-14-2009 8:57 PM Coyote has not yet responded

    
bluegenes
Member (Idle past 558 days)
Posts: 3119
From: U.K.
Joined: 01-24-2007


(2)
Message 14 of 149 (530826)
10-15-2009 5:57 AM
Reply to: Message 8 by Colin
10-14-2009 8:19 PM


Re: Targets are for creationists.
Hello, Colin.

I think you've missed my point about targets.

Colin writes:

If we deny ourselves permission to suggest evolution has any direction or trend from which to make predictions, It becomes a fit-all theory, with all the consistency of a piece of play dough.

If you give an organism specific targets, as we do with P. falciparum by challenging it with various treatments, evolution is under no obligation to solve the problem. In mammals, the equivalent to 10^20 P. falciparum, adjusting for mutation rates (which Behe I think correctly does) might be 10^12. But whatever it is, it's still an enormous number of individuals.

Supposing we gave humans a target by poisoning them regularly with arsenic, and it happened to be a 10^12 sequence of mutations that would enable us to deal with arsenic poisoning, we'd be extremely unlikely to hit on it, and if we were all being poisoned, would go extinct. No problem for evolution. Extinction happens all the time.

But, in the real world, we don't require such a rare sequence of survival dependent mutations at this particular moment, and we're here.

So, let's give ourselves another target that would be advantageous. What about a mechanism in the eye that would enable us to adjust lens shape/position in a way that eliminated short sightedness? We haven't got that particular feature, and perhaps it's a "10^12" feature. So, we've made up a target that evolution hasn't yet achieved. But there may well be a whole field of "10^12" advantageous mutation sequences, in which case we would have recieved some of them.

Indeed, that sight adjustment feature being of general advantage to all mammals, it wouldn't be surprising if at least one species did have it, and that could apply even if it was a rarer 10^20 feature.

If you give a specific species of mammal the specific target of hitting a given "10^12" sequence, it will be unlikely. But give it the general challenge of hitting some advantageous "10^12"s out of many, then some'll happen.

Would you like to calculate how many "10^12" sequences would have become fixed in our own lineage since we became sexually reproducing organisms without knowing how many possible "10^12" advantageous sequences there have been? If the figure is 1,000,000,000 possible such sequences, then one would have been completed in every 1000 individuals, but if there were only 1000, then one would have been completed in every billion individuals, and if these are general advantages, our fish ancestors would have got them all fairly quickly.

And what about rare "10^20" mutation sequences? How many could have been advantageous to our lineage? Or all tetrapods? Or all mammals?

Does Michael Behe know? Has he done the maths?

Of course not!

Edited by bluegenes, : No reason given.


This message is a reply to:
 Message 8 by Colin, posted 10-14-2009 8:19 PM Colin has responded

Replies to this message:
 Message 17 by Colin, posted 10-16-2009 5:06 AM bluegenes has not yet responded

  
Colin
Junior Member (Idle past 3326 days)
Posts: 27
From: Adelaide, Australia.
Joined: 10-14-2009


Message 15 of 149 (530985)
10-15-2009 5:33 PM
Reply to: Message 12 by Modulous
10-14-2009 9:18 PM


Re: What Behe's calculations actually mean for human evolution
Hi Modulus, this is a good response, and i do have thoughts about this. I have been away from home since yesterday, so will reply to your post (and any others tonight - about 8 hours from now).

Thanks, Colin.


This message is a reply to:
 Message 12 by Modulous, posted 10-14-2009 9:18 PM Modulous has acknowledged this reply

    
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