"Robert Karl Stonjek"  wrote 



> . . . many species of stick insects re-evolved wings,
> traits preserved in dormant DNA, over the course of 
> 50 million years -- an idea that flies in the face of 
> what insect evolutionary biologists believe.
> 
> The initial response was, 'You're wrong. Impossible, 
> impossible, impossible,' " said Michael Whiting, . . .




Robert,

This subject was discussed in this forum in June of 2001.  
I cut and pasted some choice excerpts below.  As you can 
see it was considered controversial when I introduced it 
back then.  I think the central message here is to not 
assume that the individual is the one and only unit of 
selection.


********************************************************

Jim McGinn Said, in June 2001:

> > Correct me if I'm wrong but much (I don't know what 
> > percentage) of our genome is stored, ie. it's 
> > reflective of past morphologies going back millions 
> > of years in ancestral lineage.

> I don't know exactly what 'stored variation' you're 
> referring to - evolution tends to proceed by adaptation 
> and expansion of the old genes and morphologies rather 
> than by swapping in new ones.

Are you (we) sure of this?  I'm not trying to be difficult 
here I'm really wondering if this is something you (we) 
know or if this is something that--like much of current 
thinking--has just been assumed and nobody bothered to 
question it.  Moreover I'm wondering what function the 
noncoding portions of genes would serve if not this 
"storage" function, in one way or another.


********************************************************

Jim McGinn Said, in June 2001:

It would make sense to file away old sets of genes since 
lineages often double back over themselves.  It's easier 
to use things that worked in the past rather than to have 
to keep reinventing the wheel.

Evolution is expensive.  Genes are cheap.

********************************************************

Jim McGinn Said, in June 2001:

"pz"  wrote 
>  "Jim McGinn"  wrote:
> > "pz"  wrote 
> > >  "Jim McGinn"  wrote:
> > >
> > > [snip]
> > >
> > > > It would make sense to file away old sets of genes since
> > > > lineages often double back over themselves.  It's easier
> > > > to use things that worked in the past rather than to have
> > > > to keep reinventing the wheel.
> > >
> > > Are you suggesting that organisms maintain currently
> > > non-functional genes as an adaptive strategy, for their
> > > utility in future generations?

> > Yes, this is what I'm hypothesizing.
>
> Your honesty is appreciated, and is the source of considerable
> amusement.

Might I suggest that it is your own simplemindedness that is the 
true source of your amusement.

> So, how does this work? If, for instance, I happened to carry
> some mutation that doesn't do anything right now, but might
> confer greater resistance to a pathogen that might exist a
> hundred years from now, how does it improve the likelihood that
> I would reach adulthood, find a mate, and have children?

It doesn't.

> What does it do for my kids?

Nothing.

> How does this feature generate any kind
> of positive selection for me?

It doesn't.

> Say this particular pathogen for which I am supremely well
> adapted never evolves. Is there a Temporal Reconciliation Fairy
> that travels into the past to erase my putative selective
> advantages retroactively?

No.

 

This is what it comes down to:

You have mistakenly assumed, in the tradition of neoDarwinism, 
that the only unit of selection (the only level of biological 
phenomena that can be the focus of selection) is the individual.  
This is a simpleminded and easily disproven notion.

Let's say, for instance, that instead of focussing on the 
individuals, as you did in your questions above, you focussed on 
the lineage as the unit of selection.  Now ask the same questions.  
Would a lineage (or even a population) benefit from the functional 
ability to employ genes as a means of storing adaptations that were 
successful in the past?  Would lineages that possessed this ability 
be more adaptive than lineages that don't?  I think if you think it 
through you will realize that the answer to both of these questions 
is yes.

You see, Mr. Myers, one of the best ways to make advances in the 
field of evolutionary biology is by seeing beyond the assumptions 
of our evolutionary forefathers.

*********************************************************

Jim McGinn Said, in June 2001:

> [moderator's note: I think it's a fair question,
> Jim: what mechanism promotes the production
> and retention of adaptations to distant future adversities,

Mechanism?  Are you looking for an evolutionary mechanism?  The evolutionary
mechanism is natural selection.  (As I explained it is a lineage-level
adaptation--why this seems to be so hard for you neoDarwinists to
conceptualize is something I can't explain.  You all seem to be drawing off
some imaginary principle that the individual is the only valid unit of
selection yet nobody seems to want to explain how or why.)  The proximate
(literal) mechanism involves functionality of genes.  I won't pretend to
know the specifics on this.  (But part of this mechanistic ability involves
the fact that inbreeding is the mechanism by which noncoding genes are
expressed phenotypically.)

> given
> that they have some immediate cost (metabolic, if nothing else)?

I agree there will always be a cost.

> Sure, my 100-generations-later descendents may benefit from this
> (dramatically) pre-adaptation, but what if the cost incurred to
> maintain it in the absence of the relevant selection pressure is,
> in the near-term, maladaptive? - JAH]

In the near term (let's say that by near term we mean one generation) it
will *always* be maladaptive.  This follows from the fact that, as you
state, there will always be costs (metabolic, if nothing else).  But should
we assume that natural selection only works on the near term?  Why would we
want to make this assumption?  Why wouldn't we want the term to be narrower
still, ie 1/100th of a generation.  Why not wider still, hundreds of
generations?

Remember: Evolution is expensive.  Genes are cheap.

Jim
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