FW: Heritability and generative entrenchment

[Nick Thompson]

Lee,

Is differential selection the equivalent of "heat" in this metaphor?

N.  

Nicholas Thompson
nickthompson at earthlink.net
http://home.earthlink.net/~nickthompson


> [Original Message]
> From: <lrudolph at meganet.net>
> To: <friam at redfish.com>; Jaan Valsiner <jvalsiner at clarku.edu>;
<ppgb at cam.ac.uk>; lrudolph <lrudolph at black.clarku.edu>;
<dwilson at binghamton.edu>; <rsokol at clarku.edu>; echarles
<echarles at clarku.edu>; elescak <elescak at clarku.edu>; sbarr
<sbarr at clarku.edu>; jogreen <jogreen at clarku.edu>; Gbarker
<Gbarker at bucknell.edu>; <nickthompson at earthlink.net>
> Cc: <w-wimsatt at uchicago.edu>; <jcschank at ucdavis.edu>; Carl Tollander
<carl at plektyx.com>

> Date: 5/21/2006 12:10:02 PM
> Subject: Re: FW: Heritability and generative entrenchment
>
> To paraphrase the friend of the Dustin Hoffman character's
> parents at the graduation party, "Just two words: simulated
> annealing."  Accepting arguendo that "a parameter space with
> many local stable equilibria" is the appropriate model, I still don't
> see why it can't happen that--even "When a biological system is
> in the basin of attraction for a particular local equilibrium" and is
> thus "generatively entrenched"--the (metaphorical) heat might
> not get turned up and down irregularly, allowing some systems
> to jump out of one basin of attraction (when they've been heated
> up) and then settle into another more or less nearby basin (when
> they cool down).
>
> I don't know your literature, so for all I know this kind of thing
> has been considered and debunked long ago, but my new friends
> in the protein-conformation-modelling community seem to be willing
> to do S.A. all the time. (I don't know if they claim it's happening *in
> the biological system* where the protein is being assembled; they
> may *only* be using it artefactually inside the black-box part of
> their model, to get the model out of locally energy-minimizing
> conformations that aren't physically realistic so that it can have
> a better chance of falling into a more realistic local stable
> equilibrium.  But I do know they use it.)
>
>
> > Hi everybody,
> >
> > Forgive me for casting such a wide net, but we seem to be skating very
> > close to what Carl Tollander calls "artificial epigenesis and I want to
> > keep the conversation as open as possible until I see who is

interested.  
> >
> > David Wilson (attached and below) has taken the discussion in the
direction
> > I hoped it might turn .... that selection might consist of unstable
> > relations amongst stable arrays. Everybody is talking as if the
elements in
> > the arrays are genes, but there is no particular reason not to include
> > epigenetic nodes as well.   The implication for my question on
inheritance
> > is that all the chaos in the genetic-epigenitic system is going on a
level
> > BELOW where selection is going on.  This might seem to beg the question
> > concerning inheritance ... what "force" holds together the stable
arrays?
> > However, at this early stage of my reading, Wimsatt and Schank seem to
be
> > saying that the stable arrays are high  entropy .. i.e., they hang
together
> > because that's where randomization takes them.  
> >
> > I am very excited about all of this, as you can see, but as you can also
> > see, I should shut up and go back to reading before I say more.  Thanks
for
> > your patience.  Be sure to read the message below and the attachment if
you

> > are interested.
> >
> > thanks, all,
> >
> > Nick
> >
> > Nicholas Thompson
> > nickthompson at earthlink.net
> > http://home.earthlink.net/~nickthompson
> >
> >
> > > [Original Message]
> > > From: David Sloan Wilson <dwilson at binghamton.edu>
> > > To: <nickthompson at earthlink.net>
> > > Date: 5/21/2006 8:35:45 AM
> > > Subject: Heritability and generative entrenchment
> > >
> > > Dear Nick,
> > >
> > > Thanks for your interesting message. I'm sending this reply to you

only
> > > rather than the whole group--I'll let you be the judge of what the
> > > whole group sees and in what manner.
> > >
> > > Consider a parameter space with many local stable equilibria.  When a
> > > biological system is in the basin of attraction for a particular
local
> > > equilibrium, it is generatively entrenched and here is a problem for
> > > heritability. However, there can still be selection among multiple
> > > basins of attraction, providing a concept of heritability. I discuss
> > > this in the following paper titled "Natural Selection and Complex
> > > Systems: a complex interaction."
> > >
> > >
> >
>