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Author Topic:   Precedence of Phenotype or Genotype in the evolution of 'novel' traits.
RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 5 of 13 (458239)
02-27-2008 9:54 PM
Reply to: Message 1 by Wounded King
02-26-2008 11:44 AM


Is there a coherent argument to be made for any sort of entirely genetically independent epigenetic inheritance becoming genetically encoded over generations?
My understanding is that chemicals (hormones to pollutants) can change the way specific organisms exposed to them develop and mature into adult organisms capable of reproduction. Such developmental traits would be inheritable as long as the chemical exposure lasts. Mutations can then occur that have the same effect without the chemical exposure, possibly by disabling development that would occur without the chemicals.
An example of an environmental effect is the different heat during development that changes sex in alligators. Another example is that selecting for different adrenaline levels in russian farm foxes results in "domestic breed" traits in foxes similar to dog traits.
It seems to me that this would have to be a process where a number of different mutations would have the same effect.
The problem is that there is no evidence this is in any way connected to any 'creative response'.
To be a "creative response" - ie intentional - you would have different possible responses to the same stimulus from otherwise identical organisms, all of which would be beneficial.
This obviously does not occur.
Is too much emphasis put on purely genetic changes and not on the long term interactions between the genotype and the environment?
Yes.
Enjoy.

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This message is a reply to:
 Message 1 by Wounded King, posted 02-26-2008 11:44 AM Wounded King has not replied

Replies to this message:
 Message 7 by Blue Jay, posted 02-28-2008 12:57 AM RAZD has replied

  
RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 13 of 13 (458576)
02-29-2008 10:56 PM
Reply to: Message 7 by Blue Jay
02-28-2008 12:57 AM


Re: Adaptive Radiation
I think adaptive radiation results from responding differently to the same environment.
I think WoundedKnight answered most of this, but just want to point out that what I was positing was not different results from slightly different organisms, but actually identical organisms, would have to be able to react (phenotype) in a multiplicity of ways to the same stimulus, all beneficial (for bertvan's idea to be valid).
But, when pomace flies (genus Drosophila) reached Hawaii,
Existing population full of diversity, not clonal. I was trying to eliminate this variable from the thought experiment.
Enjoy.

we are limited in our ability to understand
by our ability to understand
RebelAAmericanOZen[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) • • •

This message is a reply to:
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