Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 65 (9073 total)
79 online now:
dwise1, kjsimons (2 members, 77 visitors)
Newest Member: FossilDiscovery
Post Volume: Total: 893,263 Year: 4,375/6,534 Month: 589/900 Week: 113/182 Day: 20/27 Hour: 0/1

Announcements: Security Update Released


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   The Death Knell for ID?
PaulK
Member
Posts: 17167
Joined: 01-10-2003
Member Rating: 3.7


Message 55 of 102 (652745)
02-15-2012 6:35 PM
Reply to: Message 54 by Genomicus
02-15-2012 6:21 PM


quote:

That is not my understanding of Behe's position. IMO, Behe suggests that it is implausible for an IC system to evolve because it would have to involve a circuitous, indirect Darwinian pathway which is much more improbable than a "direct" Darwinian pathway consisting of gradual improvements on a basic function.

That was his argument, in the days of Darwin's Black Box but I don't think it's his argument now. I think his argument now is that some evolutionary changes require simultaneous mutations (at least two specific mutations) and are too improbable to occur without assistance. The problem with this is showing that the mutations must be simultaneous and I don't think that there are any proven examples yet.

The argument you give above has some serious problems. While the direct pathway might be the simplest means of obtaining a specific result that's really thinking of evolution as working like an intelligent designer - seeking the best way to get to a pre-specified goal. It seems to me more likely that evolution will often follow "indirect" routes because it is NOT goal directed. Looking with hindsight on the probability of the path actually followed is likely no more useful than looking with hindsight on the result of the lottery. And if evolution follows indirect paths we should expect it to reach solutions which can only be found by following indirect paths.


This message is a reply to:
 Message 54 by Genomicus, posted 02-15-2012 6:21 PM Genomicus has replied

Replies to this message:
 Message 56 by Genomicus, posted 02-15-2012 6:41 PM PaulK has replied

  
PaulK
Member
Posts: 17167
Joined: 01-10-2003
Member Rating: 3.7


Message 62 of 102 (652774)
02-16-2012 1:41 AM
Reply to: Message 56 by Genomicus
02-15-2012 6:41 PM


quote:

Behe acknowledges that if a function requires two specific mutations - each of which are, in themselves, non-adaptive - such a function can evolve. Chloroquine resistance is an example of this, according to him.

But isn't it true that he considers it extremely unlikely, and that this is the heart of his case ?

quote:

Umm, I'm not making any argument regarding irreducible complexity. I was merely stating what Behe's position on irreducible complexity is. I wasn't saying that I agree with him.

But does Behe still believe it ? Is it still his position ? At one point he had the idea of changing the definition of irreducible complexity completely, and his more recent argument seems a development of that. Certainly that gives me the impression that his thinking on the matter has changed - and he never had a solid argument against indirect routes in the first place.


This message is a reply to:
 Message 56 by Genomicus, posted 02-15-2012 6:41 PM Genomicus has replied

Replies to this message:
 Message 64 by Genomicus, posted 02-16-2012 4:06 AM PaulK has replied

  
PaulK
Member
Posts: 17167
Joined: 01-10-2003
Member Rating: 3.7


Message 65 of 102 (652784)
02-16-2012 4:23 AM
Reply to: Message 64 by Genomicus
02-16-2012 4:06 AM


quote:

Behe considers the evolution of a function that requires two individually non-adaptive mutations to be implausible for primates

So, in fact, you were doing a rather poor job of clarifying his position by making a blanket claim that he believed that such functions could evolve. Wouldn't it have been better to clarify the population issue at the start ?

quote:

I really am not quite sure what Behe's current stand on the issue of irreducible complexity is. However, on the surface at least, it seems that it's less probable for an IC system to evolve than for a non-IC system to evolve.

If you aren't sure of his position then you can't really clarify what it is, can you?

As for your other assertion, the relative probability of evolving a specific function by a specific direct route versus a specific indirect route would seem to be completely irrelevant - even if we do not consider the fact that evolution has no preference for direct over indirect routes.


This message is a reply to:
 Message 64 by Genomicus, posted 02-16-2012 4:06 AM Genomicus has replied

Replies to this message:
 Message 66 by Genomicus, posted 02-16-2012 4:41 AM PaulK has replied

  
PaulK
Member
Posts: 17167
Joined: 01-10-2003
Member Rating: 3.7


Message 68 of 102 (652789)
02-16-2012 5:04 AM
Reply to: Message 66 by Genomicus
02-16-2012 4:41 AM


quote:

Well, Behe does in fact believe that such functions can evolve - and since the topic of this thread involved phages, I was clarifying his position with regards to viruses and bacteria.

Provided the population is large enough... Is the population in the experiment large enough to account for 4 mutations arising simultaneously ? In 24 out of 96 cases?

Or are you going to argue that all 4 mutations are beneficial, as required by Behe's argument?

quote:

I can indeed clarify what his position is with regards to the evolution of functions requiring two or more simultaneous mutations.

Now that's just a little disingenuous given that the context was Behe's views on the evolution of IC system.

quote:

It would seem to be completely irrelevant to what?

To the assertion that I was explicitly addressing. Reading in context is often helpful. But just to remind you of what you said, here it is again:


it seems that it's less probable for an IC system to evolve than for a non-IC system to evolve.

This message is a reply to:
 Message 66 by Genomicus, posted 02-16-2012 4:41 AM Genomicus has replied

Replies to this message:
 Message 69 by Genomicus, posted 02-16-2012 5:12 AM PaulK has replied

  
PaulK
Member
Posts: 17167
Joined: 01-10-2003
Member Rating: 3.7


Message 76 of 102 (652849)
02-16-2012 2:28 PM
Reply to: Message 69 by Genomicus
02-16-2012 5:12 AM


quote:

Behe would argue that four simultaneous mutations is too implausible - even for viruses and bacteria. This study does not report that all four mutations must arise simultaneously in order to confer a selective advantage. Indeed, it could be that each mutation conferred some selective advantage.

So why not concentrate on that rather than arguing about the number of simultaneous mutations that Behe allows (and managing to miss the point that it is numbers - population size - that are the most important issue)

quote:

If I understand Trixie's main point correctly, then it is that ID proponents hold that the evolution of OmpF is extremely implausible because several mutations would be required before any selective advantage appears. Possibly, we're not communicating very well, though.

That's the problem when you ignore the context. You fail to understand the points being made. The point here is that your "clarification" of Behe's views on IC systems, assumed that Behe still held to the views in Darwin's Black Box . But it is far from clear that that is true, given that Edge of Evolution seems to derive from a radical redefinition of IC that Behe suggested (which in itself indicates that Behe realised that his original argument was in trouble).


This message is a reply to:
 Message 69 by Genomicus, posted 02-16-2012 5:12 AM Genomicus has replied

Replies to this message:
 Message 78 by Genomicus, posted 02-16-2012 9:59 PM PaulK has replied

  
PaulK
Member
Posts: 17167
Joined: 01-10-2003
Member Rating: 3.7


Message 79 of 102 (652965)
02-17-2012 1:44 AM
Reply to: Message 78 by Genomicus
02-16-2012 9:59 PM


quote:

I have absolutely no problem with concentrating on the implications of the study reported by Trixie, except that it'd be a touch superfluous since I don't think I could do better than Wounded King in explaining why multiple simultaneous mutations are not needed for the OmpF function to evolve in these phages.

So the only bit of your posts that might be useful has already been done better. Why post at all in that case ?

quote:

I suspect that you have not read EofE. In that book, Behe only mentioned irreducible complexity en passant

Unless Behe indicated that he still held to the views expressed in Darwin's Black Box that is irrelevant - since that is the point we are discussing, as I keep pointing out. And you have already admitted that you do not know if Behe still holds to that position or not, so I fail to see why you can't simply agree that you were wrong to try to "clarify" his position on IC and leave it at that.

I begin to think that the "communications problem" you referred to is the failure of your continual attempts to change the subject.


This message is a reply to:
 Message 78 by Genomicus, posted 02-16-2012 9:59 PM Genomicus has replied

Replies to this message:
 Message 80 by Genomicus, posted 02-17-2012 2:36 AM PaulK has replied

  
PaulK
Member
Posts: 17167
Joined: 01-10-2003
Member Rating: 3.7


Message 81 of 102 (652970)
02-17-2012 3:10 AM
Reply to: Message 80 by Genomicus
02-17-2012 2:36 AM


Remember writing this ?

That is not my understanding of Behe's position. IMO, Behe suggests that it is implausible for an IC system to evolve because it would have to involve a circuitous, indirect Darwinian pathway which is much more improbable than a "direct" Darwinian pathway consisting of gradual improvements on a basic function.

This message is a reply to:
 Message 80 by Genomicus, posted 02-17-2012 2:36 AM Genomicus has replied

Replies to this message:
 Message 82 by Genomicus, posted 02-17-2012 3:20 AM PaulK has taken no action

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.1
Innovative software from Qwixotic © 2022