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Author Topic:   Mimicry and neodarwinism
MartinV 
Suspended Member (Idle past 5905 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 181 of 188 (396665)
04-21-2007 4:19 PM
Reply to: Message 180 by NosyNed
04-21-2007 3:54 PM


Re: Misuse of Punc eq?
My point is that it was Punnet (author of Punnet square) opinion that
butterflies mimicry aroused via saltationism. It seems that saltationism as a plausible explanation of mimicry recurs back in disguise of "macromutation", "punctuated evolution" or "mutation with great phenotypic effects".

This message is a reply to:
 Message 180 by NosyNed, posted 04-21-2007 3:54 PM NosyNed has replied

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 Message 182 by NosyNed, posted 04-21-2007 4:28 PM MartinV has replied

NosyNed
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Posts: 9005
From: Canada
Joined: 04-04-2003


Message 182 of 188 (396667)
04-21-2007 4:28 PM
Reply to: Message 181 by MartinV
04-21-2007 4:19 PM


The real problem
The real problem "Martin" is your inability to deal with complexities and subtleties. There is a gradiation between very minor phenotypical effects and what is usually refered to as saltation.
Since we have known examples of what, I think, can legitimately be called saltation it can't be ruled out. However, once you are below speciation there is no firm line where we can stop calling it a large mutaion and simply refer to it as 'regular' mutation.
The argument being discussed in the paper, as best as I can make out is whether a large jump is ever needed in the development of mimicry or not. However, I don't know where one would try to draw a line defining "large". Such subtle distinctions seem to be a bit difficult for you to grasp. Keep up the good work.
Edited by NosyNed, : spelling again

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 Message 181 by MartinV, posted 04-21-2007 4:19 PM MartinV has replied

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MartinV 
Suspended Member (Idle past 5905 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 183 of 188 (396673)
04-21-2007 5:09 PM
Reply to: Message 182 by NosyNed
04-21-2007 4:28 PM


Re: The real problem
We have already discussed here polymorphic mimic Papilio Dardanus.
The differences between morphs are great - it requires on my opinion strong belief in darwinism to see behind evolution of it as its source "random mutations" - be it "macromutation" or "mutation with great phenotypic effect".
Even accepting theory of "punctuated evolution" requires to believe that "macromutation" hit the resemblance of the model almost exactly in the first step (before "refinement" of it take place). Especially when wings pattern/coloration of model are complicated ones and differ considerably from the presumed ancestor of mimic darwinian scientists use very knotty explanation.

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 Message 186 by Wounded King, posted 05-07-2007 6:57 PM MartinV has not replied

MartinV 
Suspended Member (Idle past 5905 days)
Posts: 502
From: Slovakia, Bratislava
Joined: 08-28-2006


Message 184 of 188 (399191)
05-04-2007 11:54 AM


Dawkins on mimicry
Richard Dawkins criticized in his Blind watchmaker another Richard - Richard Goldschmidt (together with Gould). Goldschmidt as prominent scientist explained mimicry like Punnett due saltationism. Dawkins:
quote:
The German-American geneticist Richard Goldschmidt is the most distinguished of those who have argued that the early evolution of such resemblances could not have been favoured by natural selection. As Gould, an admirer of Goldschmidt, said of dung-mimicking insects: ”can there be any edge in looking 5 per cent like a turd?’ Largely through Gould’s influence, it has recently become fashionable to say that Goldschmidt was underrated in his own lifetime, and that he really has much to teach us. Here is a sample of his reasoning. Ford speaks . . . of any mutation which chances to give a ”remote resemblance’ to a more protected species, from which some advantage, however slight, might accrue. We must ask how remote the resemblance can be to have selective value. Can we really assume that the birds and monkeys and also mantids are such wonderful observers (or that some very clever ones among them are) to notice a ”remote’ resemblance and be repelled by it? I think that this is asking too much. Such sarcasm ill becomes anybody on the shaky ground that Goldschmidt here treads. Wonderful observers? Very clever ones among them? Anybody would think the birds and monkeys benefited from being fooled by the remote resemblance! Goldschmidt might rather have said: ”Can we really assume that the birds, etc. are such poor observers (or that some very stupid ones among them are)?’ Nevertheless, there is a real dilemma here . .
Dawkins continues his reasoning - as far as I can judge - postulating a brand new theory.
quote:
But if I, with the very same eyes and brain, am walking through a forest at dusk, I may well fail to distinguish almost any dullcoloured insect from the twigs that abound everywhere. The image of the insect may pass over the edge of my retina rather than the more acute central region. The insect may be 50 yards away, and so make only a tiny image on my retina.
So mimicry resemblances developed gradually in semidarkenss and dusks when distinction between mimic and its model was undetectable enough to confuse predator.
Obviously in the case of Mullerian mimicry Dawkins would consider the predator to be still aware of patterns of the model - and yet the at the same time the predator (because of dusk) was probably unaware of the patterns of another unpalatable species - the mimic ancestor. Predator mistook in dusk one unpalatable butterfly for another unpalatable butterfly.
Of course to such Dawkins phantasies believe only those who didn't read on mimicry anything. Because even darwinian scientists like Fr. Nijhout postulate first evolutionary step in resemblance towards the model as great one (mutation with big effects - darwinian newspeak for saltationism - in the case of Batesian mimicry I admit).
Translating saltationism into neodarwinian newspeak:
quote:
"Initial step in the evolution of mimicry is likely to have been due to a genetic effect of large magnitude".
See my initial post in this thread.
Edited by MartinV, : No reason given.
Edited by MartinV, : Nijhout adressed Batesian mimicry of P.dardanus

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 Message 185 by Zhimbo, posted 05-04-2007 12:55 PM MartinV has not replied

Zhimbo
Member (Idle past 6088 days)
Posts: 571
From: New Hampshire, USA
Joined: 07-28-2001


Message 185 of 188 (399205)
05-04-2007 12:55 PM
Reply to: Message 184 by MartinV
05-04-2007 11:54 AM


Re: Dawkins on mimicry
I've only sampled this thread, so I'm sure I'm repeating someone, but it certainly needs to be repeated, if so.
"Large effects" of mutation are not a problem for Darwinian evolution, at all - if by "large effect" you mean large phenotypic effect. What *IS* a problem would be the necessity of multiple simultaneous mutations. That kind of "large" mutation is not part of Neodarwinian theory.
"Large phenotypic effects" and "many simultaneous mutations" are different concepts.
"Saltationism" that proposes "large effects" of the first kind are part of neodarwinian evolutionary theory. Simple as that. No conflict, whatsoever.
"Saltationism" that proposes "large" mutations that require many *simultaneous* mutations are not part of neodarwinian theory.
Personally, I don't see the need for either of these for the evolution of mimicry, as Dawkin's explanation that you quote seems like obvious common sense to me, but even if the first kind of "saltationism" is necessary, it presents exactly ZERO challenge to contemporary evolutionary theory.
I can't imagine this hasn't been brought up in 13 pages, but there it is again.
Edited by Zhimbo, : typo fix

This message is a reply to:
 Message 184 by MartinV, posted 05-04-2007 11:54 AM MartinV has not replied

Wounded King
Member (Idle past 109 days)
Posts: 4149
From: Cincinnati, Ohio, USA
Joined: 04-09-2003


Message 186 of 188 (399753)
05-07-2007 6:57 PM
Reply to: Message 183 by MartinV
04-21-2007 5:09 PM


Re: The real problem
We have already discussed here polymorphic mimic Papilio Dardanus.
We certainly have and here you seem to be merely blindy restating your previous assumptions and assertions which have been addressed several times.
The whole point is to move the debate on, not to take it right back to the beginning and start over again, as you have initiated since Zhimbo is now making many of the same points to you that I made on the first page of this thread.
TTFN,
WK

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 Message 183 by MartinV, posted 04-21-2007 5:09 PM MartinV has not replied

Replies to this message:
 Message 187 by Zhimbo, posted 05-08-2007 11:59 AM Wounded King has not replied

Zhimbo
Member (Idle past 6088 days)
Posts: 571
From: New Hampshire, USA
Joined: 07-28-2001


Message 187 of 188 (399843)
05-08-2007 11:59 AM
Reply to: Message 186 by Wounded King
05-07-2007 6:57 PM


Re: The real problem
Indeed, WK - MartinV's latest post showed no appreciation of the difference between large phenotypic effects vs. multiple mutations.
This discussion is pointless unless that distinction is recognized and understood and maintained. That's THE key point.

This message is a reply to:
 Message 186 by Wounded King, posted 05-07-2007 6:57 PM Wounded King has not replied

Adminnemooseus
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Joined: 09-26-2002


Message 188 of 188 (411113)
07-18-2007 11:38 PM


Closing topic
This topic has been judged to be a mess, and has been supplanted by the new topic Mimicry: Please help me understand how.
Closing this one down.
Adminnemooseus
Edited by Adminnemooseus, : Change ID.

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