[FRIAM] Friday Fodder

Wed Mar 24 17:33:59 EDT 2021

Dave, 

I am going to lead my larding by resending what I sent before, because
nobody seems to have read it.

Wow, Dave!  I will "lard" this by Friday!  Watch this space.  For the
moment, let me say only the following.  The hyena story, pushing 50 years by
now, does have the feel of a well worn tale.  I have not been back to visit
that literature since forever, so you are right to be  suspicious.  But
remember, the tale is told only to argue for what a spandrel might be, if
ever there was a spandrel.  So we have two separate issues.  One is the
definition of a spandrel; the other is the question of whether any spandrels
exist.  Please keep that separation in mind as we discuss this further.  I
further confess my fondness for Kipling (See attached).  I am probably in
the last generation of grandparents to read Kipling's Just So Stories to his
grand children;  they are, occasionally, so casually racist that I have to
edit as I read.  And yes you do point to a terrible weakness in all
evolutionary explanation.  They are historical explanations based on the
comparative method, with all the perils that that sort of explanation
entails.  (John Dodson take note.) But, after all, so is cosmology, and
plate tectonics,  so let's not panic yet.  

This  passage was meant to concede much about Darwinian Explanation and the
text to illustrate how any reasonably alert human being (like a child, for
instance) can expose its weaknesses.  I don't think there was anything bendy
about it.  

For the promised larding, please look down.

Nick Thompson

ThompNickSon2 at gmail.com <mailto:ThompNickSon2 at gmail.com> 

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

From: Friam <friam-bounces at redfish.com <mailto:friam-bounces at redfish.com> >
On Behalf Of Prof David West
Sent: Tuesday, March 23, 2021 9:12 AM
To: friam at redfish.com <mailto:friam at redfish.com> 
Subject: [FRIAM] Friday Fodder

Because I left before it ended, I have no idea how the spandrel discussion
ended. Nick requested an explanation/elaboration/justification for my
continued skepticism/resistance (other than being willfully obstinate for no
reason) to the notion of spandrel. Hence the following - elaborated beyond
the specific question of spandrel  as fodder for continuing discussion next
Friday.

I am convinced that evolutionary biologists are secretly required to read
Rudyard Kipling as prerequisite to the granting of a Ph.D.. Because, every
story about the evolution of a specific feature - Friday it was the
pseudo-penis of female hyenas - sounds like, and is as convincing as, one of
Kipling's Just So stories. [Yes, trolling.] [NST==> This is why  it so
important to understand the limitations of any historical explanation and
particularly any explanation that purports to be of a one-off event.  In
order to be explained, the explained event has to be seen as a member of
some sort of class of events, which have, hitherto, behaved in some sort of
rule full way.  What I tried to do in the vignette was offer a proper
darwinian explanation in a Kiplingesque style.  The child's last question
are supposed to expose the perils of adhockery <== nst]

1.	 

2- Pseudo-penis as spandrel:

   a- Testosterone flooded female hyenas are selected because aggressive
females have survival value in matriarchal hyena society. This really seems,
to me, to pose a chicken-egg problem: matriarchy or female bullies first?
[NST==> Should I be afraid of chicken egg problems?  It just seems like
positive feed back to me. <== nst]

   b- Testosterone flooding creates a space - a spandrel - a space that is
then "decorated." One example of 'decoration' is the pseudo-penis.

[NST===>I think your evocation of a space was insightful and it sparked a
conversation amongst after you left of what we came to call reductive
evolution.  The flooding produced a bunch of consequences, some positive,
some negative.  You would expect, now, that natural select would prune the
effects by knocking out androgen receptors in all the processes that respond
with deleterioius effects.  What makes the hyena case so striking is that
such selection has not [yet?] occurred.  Ok, so we need to have a way of
distinguishing between spandrels and their elaborations.  I would suggest
that anything we get along the line of penis development by taking a female
dog pup and lacing it with testosterone is a decent model;  anything we
don't get, is presumably an elaboration in the hyena.  So, for instance, I
don't think you would get the colorations or the pseudoscrotum, so I would
think of these as secondary elaborations or "exaptations." <===nst] 

   c- by what mechanism does the decoration come about? Nick said it was a
direct result of testosterone flooding, that "all" such results would
appear, that none of them was independently 'selected for." This is a
specific area where I fail to understand what Nick is saying and need
correction. If I heard correctly that all effects of testosterone flooding
would appear - Nick emphatically said "all" and "will" in his explanation -
then:

    -- we should not only see a clitoris run amok, but also beards, rock
hard pecs instead of pillow-breasts,  20-inch biceps, denser bones, and
overall greater muscle mass.[NST===>Well, I don't think hyenas grow beards,
but the other stuff does "come along" in female hyenas. <===nst]  

    -- the "purpose" of the pseudo-penis is aggression display and
reproductive-act dominance. 

[NST==> I wouldn't quite put it that way.  I would say that the purpose of
the coloration is all of those things.  In the first place, the pseudo-penis
is "just" a consequence of these other effects.   <== nst]

But, of all the results of testosterone flooding that "will" result, a big
penis seems the least useful for that purpose. Muscles and size would seem
more than sufficient. 

[NST==> Well, this explanation is too strong, because it predicts that
display structures would never evolve.  Aggressive animals, even
hyper-aggresssive ones, are presumably (note weasel word) selection for
avoiding conflict where they can.  <== nst]

Consider Arnold in the role of Terminator. He managed to convey a lot of
menace and dominance simply from size and overall shape; never once
brandishing his penis to intimidate anyone. (And if we assume he was as
liberal a user of steroids in his body-building career as many of his
colleagues, his penis would not have scared a squirrel.)[NST===>Frankly, I
don't know how far one can go toward masculinizing a human female by
flooding embryo and then baby with testosterone, but I think its farer than
you might think. <===nst]   

    -- Why so baroque a decoration?[NST===>Not clear what's baroque about a
penus<===nst]  

    -- Why did testosterone cause the clitoris to merge with the urethra and
the vagina? Did these not exist as separate organs in predecessor species to
the hyena? How is that even possible? [NST===>Well, all the instructions for
making a penis exist in both male and female sexes.  Which sex
characteristics develop depends heavily on the presence of testosterone.
Also, development has to have tremendous capacity to buffer environmental
vicissitudes, and those capacities can be captured for buffering against
genetic change, as well.  <===nst] is the pseudo-penis not a
clitoris-urethra-vagina at all but some kind of evolution of an avian
cloaca?[NST===>I have no idea which is more primitive, the penis or the
cloaca.  I am betting on the penis.  They are widely distributed in insects.
<===nst]  

    -- This specific decoration seems to have anti-survival consequences
(most firstborn hyenas are also stillborn) and yet this decoration seems
immune to selection. Or maybe not, we have yet to see what might succeed
hyenas a few million years from now.

[NST===>Remember.  According to the theory, the penis itself is not a
decoration.  It's an "unintended consequence".  The coloration is the
decoration (and the pseudoscrotum?) and these don't appear to cost the hyena
anything at all.  <===nst] 

3- More general issue: whole-part evolution. Jon seemed to understand what I
was trying to say last Friday on this matter.[NST===>I feel like I
completely understand your problem, but cannot solve it.  You point to, what
is for me, the most  bemusing problem in evolutionary theory, the evolution
of natural selection.  Given the developmental entanglement of traits, how
do they become modules for the purpose of selection.  The tension between
developmental biologists and Dawkins-like biologists is around this poing.
Nobody disagrees that there is a lot of entanglement and nobody disagrees
that some traits get selected.  I agree that the burden of proof lies on the
side of selection theorist to explain how selection itself is possible!
This what I find so tempting about Stephen's energy flow ideas.   Is there a
"least action" explanation for modularity?  <===nst]  

a.	Consider the peregrine falcon. Some of the traits/features that make
it a formidable predator: very lightweight bones coupled with overdeveloped
muscles which contribute to its ability to withstand G forces and make 200
mile per hour dives (and withstand the shock of kinetic energy when it hits
its prey); razor sharp talons; notched beak to sever spinal columns;
full-color binocular vision with resolution that allows seeing a pigeon at
distances greater than a mile; nictating membrane to protect from wind force
during dives; and ability to see into the ultra-violet spectrum.

   b- If I understand Darwin (a huge if): each of these features is the
result of a sequence of selected/preserved minute changes in single
molecules: e.g. keratin, opsins, crystallins. Each of these molecules are
expressed as a sequence of amino acid 'letters', 20 in number. If the string
of letters were 100 characters in length (crystallins and opsins are much
longer) then the odds of any given string are 20 to the 100 power. By
comparison, the number of hydrogen atoms in the universe is estimated to be
10 to the 90th power.

   c- If evolution proceeded with one amino acid letter pairing with a
second, getting selected, then pairing with a third, etc., each addition
being one of 20 equally probable options; then, coming up with the string
that expresses, precisely, as the falcon's beak is fantastically improbable
(winning the lottery every year since the Big Bang).

   d- This brings in the question of time. Has there been sufficient time
for a process of random change / selection to allow the formation of such a
string. This was a huge issue for Darwin because the prevailing scientific
estimate of the age of the Earth was twenty-million years. [Lord Kelvin
using the equations of thermodynamics.] This was not nearly enough time for
Darwin's evolution and he was "greatly troubled by it." Rutherford, using
radioactive decay equations, "saved" Darwin by extending the age of the
Earth to 4.5 billion years.

   e- Kind-of. If evolution literally proceeds one amino acid letter at a
time to assemble a specific string that has a probability of existing of 1 /
20 to the hundredth power (or more) - there is insufficient time since the
Big Bang for that string to emerge via chance.

   f- it seems as if some kind of short-cut is essential. Suppose you have
parallel/simultaneous evolution of 'sub-strings' and then 'main-line'
evolution proceeds upon combinations (wholes) of these strings, Then, it is
quite likely that 4.5 billion years provides sufficient time. This, it seems
to me, suggests that evolution deals with an aggregate, a whole; not
individual amino acids one-by-one, or even sub-strings one-by-one.

   g- Which circles back to the falcon. If each of the mentioned
traits/features evolved independently and sequentially then we run out of
time again. If each of the traits/features evolved independently then there
seems to be a macro-problem of how they 'just happened' to occur
simultaneously and apparently 'in concert'.

So my conclusion, apparently wrong because it disagrees with the experts in
the group, is that evolution must proceed whole-organism to whole-organism
and not, feature-trait by feature-trait the way that it is presented.

This also means, that individual feature-traits - as marvelous as the the
falcon's eye or as silly as the pseudo-penis - cannot, and should not be
"explained" independently. To do so is to focus on the 'noise' and not the
'signal'. Such efforts are the product of 19th century thinking and unworthy
of complexity scientists like yourselves.

davew

Nick Thompson

ThompNickSon2 at gmail.com <mailto:ThompNickSon2 at gmail.com> 

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

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