[FRIAM] Spandrel

[Prof David West]

your 'steelman' is pretty close.

The process of mutation-selection seems to be working on a whole — a face, just as an architect is working on a whole room or building. While doing so, a side effect, a proto-spandrel, emerges. Now the architect notices this proto-spandrel and decides it would look better if it was decorated; and she then focuses her attention on the proto-spandrel and does her thing.

What is the equivalent to the architect-with-focused-attention in Nature and why did it arise? Is it a kind of "epicycle?"

Or is it the case that multiple mutations - brain-forehead, chin, and nose occur simultaneously but purely coincidentally and it is always the whole - the face that is evolving albeit, under the covers, through a coordinated set of quasi-independet mutation-selections?

If the latter, then it would seem that the organism, as a whole, is the only thing that evolves. In every iteration, a host of random mutations occur, throughout the organism, and they work, in concert, to generate the next iteration of the whole organism.

What we see as independently evolving features — beaks, nesting behavior, eyeballs, noses, spandrels — do not exist in any real sense except as projections of our limited ability to conceptualize and deal with the complexity of the whole, as a whole?

Bonner's discussion of randomness, coupled with Wegner's demonstration that results of random change in the genome are highly likely to be both viable and consistent with the state from which they evolved.

Of course, I am merely confirming my ignorance with this.

davew



On Mon, Mar 15, 2021, at 11:11 AM, thompnickson2 at gmail.com wrote:
> Dave,

>  

> Did I understand you correctly?  Is your quandary accurately expressed below.  If genes modulate the growth of skull, and jaws differentially, how can  “face” become a thing for the purposes of natural selection.  I think this question IS the basic challenge of evolutionary theory.  It is the question of the evolution of modularity.   I have always imagined that the answer lay in some attractor in developmental systems … blah blah.  But SteveG persistently reminds me that it might be scaffolded by physical systems, in exactly the same way that life’s origins was scaffolded by the molecular structure of white smoker vents in the sea bottom.  How could physical systems scaffold natural selection?

>  

> Nick   

>  

> Nick Thompson

> ThompNickSon2 at gmail.com

> https://wordpress.clarku.edu/nthompson/

>  


> *From:* thompnickson2 at gmail.com <thompnickson2 at gmail.com> 
> *Sent:* Sunday, March 14, 2021 11:57 PM
> *To:* 'The Friday Morning Applied Complexity Coffee Group' <friam at redfish.com>
> *Subject:* RE: [FRIAM] Spandrel

>  

> All==

>  

> I want to call attention to Dave’s quandary at the end of his last message to me.   If genes are not “for” traits but for processes, how does natural selection manage to “pick out” traits.   How do you take a vastly interacting causal web and get additivity of variance out of it.  It seems to me that Steve’s pathway talk might lead to an answer to that question.  Of what process is natural selection the PRODUCT?  Who or what selects the selector? 

>  

> Nick

>  

> Nick Thompson

> ThompNickSon2 at gmail.com

> https://wordpress.clarku.edu/nthompson/

>  


> *From:* Friam <friam-bounces at redfish.com> *On Behalf Of *Eric Charles
> *Sent:* Sunday, March 14, 2021 11:01 PM
> *To:* The Friday Morning Applied Complexity Coffee Group <friam at redfish.com>
> *Subject:* Re: [FRIAM] Spandrel

>  

> Steve, 

> Yes exactly! Humans were not selected "for noses." Humans were (the argument goes) selected for shorter jaws. The "protruding" nose is what you end up with after selection shrinks the jaw. So, if you notice that humans have noses, and you jump straight to asking "Why did protruding noses evolve? What adaptive function do they serve?" you are barking up the wrong tree. Ditto impacted wisdom teeth. It would be pretty silly to assert that impacted wisdom teeth were adaptive, even though they likely resulted from natural selection through the same pressures that led to noses.

>  

> Now, the problem with the "nose" example is that, given the variation in noses around the world, it is actually quite plausible that nose size and shape IS adaptive. But that's a different issue ;- ) 

>  

>  

> On Mon, Mar 15, 2021 at 12:50 AM Steve Smith <sasmyth at swcp.com> wrote:


>> Nick -
>> 
>> Not to beat a dead Spandrel, but the nose example doesn't wash with me.  
>> 
>> In many familiar animals, the nose is perched on the end of a snout, and
>> it was the snout that was deprecated in us to the point that the
>> nostril-holes with various adaptive properties (downward facing to keep
>> rain out, hair-lined and snotty to trap dust and pollen, (mildly)
>> turbinated to support humidity/temperature regulation, sensitive to
>> support "feeling" things with one's proboscis before we smash the whole
>> face into it,  loaded with chemically sensitive cells for "smell", etc)
>> are highly diminished compared to various creatures like a daschund or
>> an elephant or an anteater.   Our nose still has significant affordances
>> similar/familiar to those listed above (serviceable smeller, filter,
>> heat/humidity exchanger, etc ) even if it is not at all prehensile or
>> particularly discriminating and if humans have a snout at all, it is a
>> highly diminished one.  
>> 
>> I suspect references to "being nosy" and "sticking our noses in other's
>> business" is borrowed from watching our snoutful familiars like horses
>> or camels or racoons or dogs "nosing around".  The proboscis of our nose
>> *points* where our eyes are looking (somewhat) so that conflation may be
>> mildly meaningful?
>> 
>> Does "butting out" connote backing out butt-first when one recognizes
>> their nosing around isn't welcome?
>> 
>> <beep><beep><beep>
>> 
>>  - Sneeze
>> 
>> 
>> 
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