R. Lopez Presentation – October 18, 2006 / Intro to Psych, Ms. Olivett
Chapter 2: Genes, Brain, and Environment / "What is the impact of the environment on the brain?"
[ An outline: dark text– via course documents, lighter text– me injected; brick text– my brain looping. ]
Mendelian
Inheritance (George Mendel, 1866)
1)
For each trait,
offspring inherit an "element" from each parent.
2)
An element that is
dominant is "apparent" or expressed.
An element that is not dominant is
"recessive."
Mendel
unknowingly imagines the workings of inheritance, without comprehending
anything
about the actual
mechanisms involved.
It would be
another fifty years before his work would inform the beginnings of classical
genetics.
The
"elements" are genes, small sections of DNA that produce specific 3-D
proteins, which in turn
form the building
blocks of our bodies and drive the processes that allow us to live.
(...so
says the text– they actually compel us to live.)
Genotype = genetic code carried by an organism.
Phenotype = observable structure or behavior of an organism.
Explicit (phenotype) and Implicit (genotype) information :::
The explicit is an expression of the implicit.
And so, phenotype is the revelation of the genotype.
Complex
Inheritance – combinations of
genes working together to produce an effect.
Actually,
"simple" inheritance is enormously complex in itself.
Consider
that the DNA encoded in the 10 trillion or so cells in a human body contains
complete instructions
for
expressing the body (fertilized egg growing furiously into conscious
being), and then directing and facilitating it
throughout
life (processing 10,000 different precisely enfolded and functioning proteins;
constructing eyes that see;
brains
that think; mouths that speak...)
II ¥ Genetic
Programs ::: The Genes Matter
By affecting our
brains (structurally, chemically, functionally) genes can also affect our
behavior.
In a '96
experiment by RYNER, a single gene is altered and affects the targeted sexual
attraction of insects.
The
genetic change alters what they desire. In complex information
systems, SMALL changes = LARGE effects.
Likewise,
the
genetic coding, or the
"books" of the
human and the chimpanzee are 99% identical.
(Think
of it: a pair of 100 page books where 99 of the pages are worded and punctuated
in exactly the same way,
with
only one page of variations.)
III ¥ Tuning
Genetic Programs ::: The Environment Matters
However
::: It's not nearly that simple!
The PHENOTYPE is
not a straight "read-out" of the GENOTYPE.
Genotype, for
example, determines the potential structure of your brain, but not
the resulting
structure in its entirety. While an acorn will
always grow into an oak tree, with oak-shaped leaves
and
oak-textured bark and mathematically determined branching patterns found in
nature– we cannot map precisely
the
individual oaken characteristics of a certain oak tree from a particular acorn.
By interacting
with and growing within an environment, the brain:
1)
Loses neural connections
it had at birth.
2) Retains
those connections used frequently.
3) Eliminates, through Pruning, those NOT used frequently.
Such changes are
called Plasticity, as the brain and its connections are molded by
experience and external forces.
For example, an
enriched environment that provides sources of interest and interaction result
in a "heavier" brain,
the added weight
a product of increased blood flow to the cortex, and the formation of new
connections.
On
the other hand– an impoverished environment will turn a brain into a
tepid bowl of oatmeal.
Plasticity is
displayed :::
1)
When interactions with
the environment shape the brain
during infancy and childhood.
2)
When the body changes so
that the sensory input changes.
3)
When we learn something
new or store new information.
4)
When compensating for
brain damage. (Other areas taking over lost functions.)
"Genes are
not destiny..." They do not set characteristics, but rather they determine
what is possible–
outlining
general parameters and pathways, as opposed to defining a precise or particular
future outcome.
IV ¥ Genes and
Environment ::: A Single System
And
now, the rest of the story...
Genes not only
instruct the fertilized egg that contains them how to go about unfurling...
a brain
that is so deeply complex that it gives rise to the amazing quality we call
consciousness,
but
in their various configurations genes also "know" how to survive a
forest fire (a stand of trees);
how
to grow in five-way symmetry (a starfish); how to grow while maintaining the
same shape;
how
to write a symphony; how to evolve...
[
We pause here for page 4 ]
PAGE 4 / The
personal + interactive :::
A
few weeks ago I mentioned that in the realm of information theory, "1+1
=3."
In a
more accurate sense, two SETS of information, when combined, give rise to new
and unforeseen
phenomena,
such as the QUALITY of depth perception from combining the view of two
separately
positioned
eyes. In the brain, millions of "1+1" combinations all add up to the
"3" of self-awareness,
and
therein lies the importance of tying together as many parts of the world as
possible, in order to add clarity,
comprehension,
and depth of consciousness.
Let
me RUN you through an example of how this works for me :::
So–
a VERY small section of DNA, just to show its double helix structure, a ladder
in spiral form.
The
line on the left is one vertical turn of the spiral, 34 angstroms long.
An
angstrom is unimaginably small, and is used to measure the diameter of atoms,
1
angstrom being the diameter of an "average" atom.
250
million angstroms in one inch. So, 80 million or so of these DNA snippets per
inch.
This
segmented line on the right? That's the same 34 angstrom length, but notice
it's
in two sections– more on that in a minute.
I
show you this both because it's beautiful, and because it's laden with meaning.
[ image
2 ]
Lower
right, snaking in, the double helix again– your DNA, of which each cell
in your body
has
2 incredibly slender meters worth (!!!) which fits by wrapping itself many
several different ways,
so
that the 2 meter strand ends up being 1 millionth of a meter long, weighing
about 6 trillionths of a gram.
By
the way– while we're speaking of "scale" and trying to envision
this: If you removed all of the empty space
inside
the atoms in our bodies, you could fit the entire human race inside the volume
of one sugar cube.
(And
the "stuff" we're made of isn't "stuff" at all, but that's
another story.)
There's
really nothing more incredible than reality.
[ image
3 ]
This
is how DNA, wrapped around those crazy histone molecules, looks wrapped around
a chromatin fiber.
Before
wrapping and folding further a few times. Ridiculous, isn't it?
[ image
4 ]
Back
to our dear friend the double helix– the 34 angstrom length of DNA.
The
segmented line is measuring the MINOR grooves (inside the ladder)
and
MAJOR grooves (outside the ladder) of the vertical spiral.
The
line is called a GOLDEN SECTION in mathematics, because it's PERFECT.
The
length of the short (13 ang) compared to the length of the long (21 ang)
is
the same as the length of the long (21 ang) compared to the length of the whole
(34 ang).
[REPEAT]
This
ratio, as it turns out, is how nature builds spirals. And much more.
[ image
5 ]
Perfect
is Perfect. The Greeks began using the golden section, or "Divine
Proportion" in architecture and sculpture
a few
thousand years ago. The lengths of the lines and the rectangular AREAs of the
Parthenon are in this ratio.
We
still use it today in art and architecture and mathematics and... everywhere.
By the way, the ratio is PHI. ("Peiy")
[
image
6 ]
And
in nature: the VOLUMEs of the chambers of the chambered nautilus grow in accord
with this formula.
Cut
an artichoke or a stalk of celery or a rose bloom at the base and you'll see
the spirals of petals or leaves working
in
exactly the same way. It determines tree branching patterns, the turn of spiral
galaxies, the patterns of sunflower seeds
or
pinecone scales, and the angled "tiling" patterns of soap bubbles,
which are identical in shape to the plates in the shell
of a
turtle, and it goes on and on and on...
[ image
7 ]
Leonardo
daVinci's "Vetruvian Man," which uses geometric golden sections in
various ways to define
the
ideal proportions of the human body. You can look it up. And you should.
[ image
8 ]
Aphrodite,
the Greek goddess of erotic love, beauty, and fertility, sculpted in accord
with the divine proportion.
[ image
9 ]
Here
is a contemporary example, Salvador Dali's "Sacrament of the Last
Supper," with apostles dissecting the lines of the table
at
the exact proper places (Vitruvian Man's outstretched arms echoed in the vault
of the ceiling), golden rectangles again rampant
in
the composition; and a DODECAHEDRON, of all things– a twelve-paned solid
with pentagonal sides that is a kind of
boiling
golden section stew, which brings us to...
[ image
10 ]
A
Dodecahedron (of all thing!) being spun vertically and proportionally and
revealing the structure,
symmetrically
once again, of the double helix.
And
if you are capable of opening to some of this, then I have just created an
ENVIRONMENT humming
with
conceptual connections, that may have forged a few new neural connections for
you, and thus altered,
hopefully
in some thrilling and expansive way, your hungry little BRAIN.
...genes also continue to function in other capacities,
making your hair fall out both randomly and in patterns,
gumming up your
arteries, deciding when its time to inject your Grandmother's arthritis into your joints,
and making the
path of blood circulation in your legs visible through the miracle of varicose
veins.
Also, genes are
constantly being turned on again / off again– producing needed substances
as they are needed;
initiating timely
processes; making repairs and adjustments; and regulating functions.
Although it may
be convenient to talk about Genes and Environment as separate factors or
discrete entities,
they are actually
different aspects of a single system. It's extremely important
to note that, when it comes to
the
"whole
picture," this is also true of every "thing" in the SYSTEM we
refer to as The Universe.
V ¥ Environment
and Genes ::: A Two-Way Street
Genes can affect
the environment / The environment can regulate the genes.
It's a SYSTEM!
There are three
ways that the genes and environment interact [Plomin '97 / Scarr &
McCartney '83]
1) Passive Interaction – when genetically shaped
tendencies of parents or siblings
create an environment that is passively received by the child.
2) Evocative (or Reactive) Interaction – when genetically
influenced characteristics
draw out or elicit behaviors from others.
3) Active
Interaction – deliberately choosing specific situations, and aggressively
avoiding
others. Constructing, shaping, or modifying situations that fit with
existing genetic tendencies
"A Fin is
a Limb is a Wing" pp. 110-135, November 2006 National Geographic.
The new issue
just out has a very sweet look at how the same gene sections in different
animals produce
variations on
themes, as indicated by the article's title. Gorgeous photographs, cutting-edge
Biology
and crystal clear
explanations of the sub-title: "How Evolution Fashioned its
Masterwork."
That's a very
mainstream source, easily accessible. You can also try Googling "golden section"
and "divine
proportion" (with the quotation marks in place). I got 382,000 hits for
golden section,
and 146,000 for
the divine version.
Another good
mainstream source is WIKIPEDIA ::: http://en.wikipedia.org/wiki/
The sections on
DNA, Protein, Chromatin, Golden Section, etc., are really fine, and even if you
don't
totally
comprehend them, they're still beautiful to look at.
(This was the
source for some of the images I've used. )
Just plug a word
into the search engine and go crazy. I do.
Try a quick tour
through PhiMatrix ::: www.phimatrix.com/contents.htm for Phi ratio grids laid over
numerous biological
forms, butterfly wing patterns, George Clooney's face, daVinci's Last Supper...
Some of the books
consulted, most of which can be found in a good library,
all of which can
be found at my house :::
Mind and
Nature: A Necessary Unity, by Gregory Bateson
Patterns in
Nature, by Peter S.
Stevens
Hypergraphics:
Visualizing Complex Relationships in Art, Science, and Technology,
Edited by David
W. Brisson
On Growth and
Form, by D'Arcy
Wentworth Thompson
Asking About
Life, by Tobin &
Dusheck
Questions,
curses, help, offerings of forgiveness :::
www.bb10k.com
After-class
I send an e-mail to my instructor :::
[QUOTE]
Tonight confirmed for me in the most succinct manner possible that
I am doing my class work just for my teachers,
in a way that is probably more true than for other students...
When I went back to my table, Ken [who also ÒpresentedÓ this day]
says: "Thanks for making me look bad!"
(I say "No-No! Listen, I've been doing readings for years, if
someone told me I had to be a medic in Iraq starting tomorrow
like you've done I'd pee myself, shit myself, and pass out!Ó), The
fellow in front of me says "What was all THAT about?
You should be an anesthesiologist, you wouldn't need drugs, just
get people to pass out by talking about stuff like that..."
and the high-school phenom next to me waits and then asks "How
long did it take you to put that together???" At least that
implied some appreciation, although he's up next week, so maybe it
was just out of fear. Yikes.
[UNQUOTE]
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