From: Dace (edace@earthlink.net)
Date: Sat 07 Jun 2003 - 19:46:10 GMT
> From: Keith Henson <hkhenson@rogers.com>
>
> At 01:57 PM 06/06/03 -0700, Dace wrote:
>
> > > From: Keith Henson <hkhenson@rogers.com>
>
> snip
>
> > > Which would you say applies to a person who has internalized the
baseball
> > > meme and knows how to play it?
> >
> >If you grow up in the USA, baseball is a meme. If you grow up in a
foreign
> >country, it's an idea.
>
> People have enough trouble trying to grasp the meme about memes. Making
> meme or not meme dependant on who hold them and how is just over the top.
The simplest answer is not always the right answer. What if you're wrong?
What good is a simple explanation if it's the wrong explanation?
> > > I can't deal with morphic fields, Scientology's space aliens, or
> > > supernatural spirits. Sorry.
> >
> >No need to be sorry, you're just a bit confused here. "Morphic field" is
> >shorthand for "morphogenetic field," a standard explanatory tool in
> >developmental biology. The field concept is utilized to explain why one
> >clump of cells becomes, say, an arm, while another clump of cells
develops
> >into a kidney, despite the fact that all the cells have identical DNA.
It's
> >generally believed that morphogenetic fields will ultimately be explained
> >according to genes, but don't hold your breath. Many developmental
> >biologists have given up this quest as a lost cause and are now fully
> >committed to mathematical explanations of fields. (Morphogenetic fields
can
> >be described with the same mathematical precision as electromagnetic or
> >grativational fields). The problem with this approach is that it seems
to
> >imply that organisms are governed by eternal equations. Of course,
> >equations do not evolve. Thus Sheldrake proposed that fields are the
> >product, not of genes or of equations, but of past, similar organisms.
As
> >organisms adapt, fields evolve. Ironically, Sheldrake's view is the most
> >easily testable and therefore the most scientific of the three
alternatives.
> >(No one has ever devised a way of testing the hypothesis that organic
form
> >arises from DNA. It's simply assumed by those who believe it.)
>
> This is off topic, but may I suggest you do a little research on this
> subject. Here are a few pointers:
>
> Embryonic Development: Putting on the finishing touches
> ... Most selector genes, including Antp and Ubx, are homeobox genes. ...
Ah, homeobox genes. You may want to do a little research yourself. I've
been aware of homeobox genes since they first came to light in the late 80s,
when I was studying biology (among other things) at the University of
Kansas. To claim that homeobox genes determine the placement of body parts
in the developing organism is like saying God determined the placement of
galaxies in the universe. Okay, so what determined God?
You're just pushing the question back another step. Since the exact same
homeobox genes are contained in every cell of the body, clearly these genes
are not responsible for the fact that some cells form into limbs while
others form into organs. Something has to inform each cell which genes
within it are supposed to be activated and which are supposed to lie
dormant.
If, as many researchers believe, ontogenesis is determined by morphogenetic
fields, we should expect malformed bodies to result from a variety of
factors besides simple genetic mutation. Indeed, this is the case. While
mutations in homeobox genes cause antennae and legs in Drosophilia to change
places, the same effect occurs from exposure to toxic chemicals, X-rays, and
excess heat. So, is the form of the body somehow contained in the amount of
heat an embryo is exposed to? That's about as likely as the idea that
bodily form is contained in genes. (See the article by Brian Goodwin in
*Beyond Neo-Darwinism,* Ho and Saunders, eds, 1984).
In fact, no reputable researcher claims that bodily form is inscribed in
genes. For years the party line has been that bodily form arises through
the "dance" of genes and proteins. Genes determine which proteins are
produced, including master proteins, which determine which genes are
expressed, and so on, round and round, in an infinite regress. Not exactly
a satisfying answer.
In *The Art of Genes* (Oxford University Press, 1999) Enrico Coen noted that
the homeobox genes in flies and humans are virtually identical. The genes
were formed by a common ancestor hundreds of millions of years ago and have
never undergone any significant changes. Recognizing that these genes
cannot therefore be responsible for forms unique to each species, Coen
concluded that cells are like little artists. That a clump of human cells
forms a human body while a clump of ant cells generates an ant body is no
different than the fact that Rembrandt always painted Rembrandts and Picasso
always painted Picassos! This is the pitiful state that reductionistic
biology has itself been reduced to.
> Similar pages
> - - Hox (Homeobox) Genes - Evolution's Saviour? -
> Hox (Homeobox) Genes Evolution's Saviour? ... Some evolutionists hailed
homeobox
> or hox genes as the saviour of evolution soon after they were discovered.
...
> www.trueorigin.org/homeobox.asp - 11k - Cached - Similar pages
You're getting your information from a creationist website? You must be
kidding.
> It is generally considered that the original pole of the egg is determined
> by an external factor. Morphogenesis is now thought to rely on chemical
> gradients, which sequentially (head to tail, front to back) activated hox
> regulator genes.
Coen goes into a lot of detail on this, but even he agrees this is not a
final answer. What, then, determines the chemical gradients?
This is not as off-topic as you might think. As an engineer, you're
predisposed to think about things in terms of mechanics. I'm having trouble
getting you to understand organic development due to interference from the
machine meme. In other words, a meme which has *replicated* in your mind is
preventing a simple piece of nonmemetic information from being *re-created*
in your mind on the basis of your cognitive capacities.
Ted
===============================================================
This was distributed via the memetics list associated with the
Journal of Memetics - Evolutionary Models of Information Transmission
For information about the journal and the list (e.g. unsubscribing)
see: http://www.cpm.mmu.ac.uk/jom-emit
This archive was generated by hypermail 2.1.5 : Sat 07 Jun 2003 - 19:49:30 GMT