>I would like to respond to your scenario about the transition from fish to
>tetrapod as an evolutionary phenomenon. In general it looks convincing. But
>I would like to ask some questions about some of the particulars, if I may.
> (BTW I am neither a YEC nor an anti-evolutionist. I just do not believe
>that Darwinian mechanisms can account for major innovations in the history of
>life, such as the transition from aquatic to terrestraial life, although they
>do explain minor variations that enhance the adaption of the innovations to
>the new environment.)
So many Christians, like me, were taught from our earliest days in the faith
that Darwinian mechanisms are unable to cause major innovations. A good friend
of mine Ray Bohlin wrote a book entitled "The Natural Limits to Biological
Change". I simply don't see this limit everyone wants to believe in. Here is
why. Consider the sequence (allowing only A,T,C,G in the positions)
A-T-G-G-C-A-T-G-C-A-C-A-T-T-G-G-A-C-T-A-G-T-C-T-A-...
If I start iteratively and randomly mutating the positions, and end up with a
sequence
A-C-G-G-C-T-T-C-A-T-C-A-T-G-G-C-A-C-T-A-G-T-C-T-A-...
where is the limit to this procedure? Mathematically I can change FROM any
sequence TO any other sequence by random replacement. There is no limit to
the sequence I can generate in this fashion.
You will recognize this as DNA sequences.
Now for your objection that I know you are making to the above. You will say
that 99.9% of all sequences won't work and are fatal. That is true. But
sequences have associated with them a mathematical object known as a phase
space or a sequence space. Each nucleotide position becomes a dimension in
the phase space. The sequence A-T represents a point in a two dimensional
phase space like this (I hope transmission of this drawing doesn't mess this
up):
*A-T-C-G
A .
T
C
G
The sequence A-A is a point in the upperleft corner of the diagram and G-G is
a point in the lower left. There are sixteen possibilities and 16 points in
the space. A 3 unit long nucleotide has a 3D phase space associated with it.
When we go to longer sequences we get a billion or more dimensional phase
space. Most of the points in the phase space don't produce living creatures.
But most phase spaces are like sponges, with caverns and connecting
passageways. Like below. The * is a solid wall the . is sequence that gives
rise to life. The phase space of a living system would look like a "Hunt the
Wumpus" game board:
********************************************************************
****.X.**********************....***********************************
*****...*****************........***********************************
***.....*************.......***..******........*********************
*****.***************.**********........****........****************
*****.***************.***********..**************............*******
*****......**********.************..**********************.....*****
******........*******.*************..*********************......****
****.....************.**************..***********************......*
******...********.........***********.......**************.....*****
********...........***........*********.....******************.*****
***********..************...************......****************.*****
************...*********.....**************....***************.*****
**....********..**********...***************...***************.*****
**..Z..*****...************.**********************************.*****
***...*****.....***********.*******************************.......**
*********......************.**************.......*********....Y....*
*********.....*************.*********......*****.************....***
***********.***************...........**********.*************....**
*******......************.....******************..*.....********...*
*********......*********.......******************......*************
********************************************************************
The phase space looks like a cavern system with passageways. The major
caverns are the stable species the passageways are the rapidly traversed
regions. The caverns explain the stasis of species and the narrow passageways
explains the punctuated part of evolution. By random mutation of sequences
one can find a path between position X and Y. There is no barrier or limit to
change. All intervening positions allow for living organisms. There are
isolated places like that marked Z which have no entry way and they may never
have an organism with that genome. In that case there is a barrier and I can
not go from X to Z.
In the above example, if I did my counting correctly, only 22% of the
locations (or sequences) allow for life, yet there are valid pathways between
the locations.
Thus to draw the point bluntly. Chimpanzee and Human each have approx. 3.5
billion nucleotide positions. We share 98% of our DNA and thus occupy two
closely neighboring caverns in DNA phase space.
Now, where does the information come from for these major changes? God
designed them into the phase spaces!!!!! Life is not creating these major
innovations. Life is DISCOVERYING what God has already created! If you start
a creature with our DNA you get a human because our cluster of points is
marked 'human' in the phase space. If you use a similar length DNA but with
1-2% changes, you can get a chimpanzee because those cluster of points in the
phase space are marked 'chimpanzee'.
Is this a purposiveless view of nature? Does this view destroy God's control?
Of course, not. God designed the phase spaces and in doing so, God was
essentially laying down a nearly undetectable railroad track which would lead
from one animal to the next, not according to an unplanned sequence of events
but according to His foreknowledge. In other words, God rigged the roulette
wheel, BY DESIGN.
What experimental evidence is there of this? Lots. 3 or 4 mutations perform
most of the physical transformation between two species of monkeyflower. These
3-4 mutations make most of the changes required to change the flower from a
bumblebee designed flower to a hummingbird designed flower. See H.D. Bradshaw
Jr., S. M. Wilbert, K. G. Otto and D. W.Schemske, "Genetic mapping of Floral
Traits Associated with Reproductive isolation in monkeyflowers (Mimulus),"
Nature, 376 Aug. 31, 1995, p. 762-765
I will answer your other questions in another post.
glenn
Foundation,Fall and Flood
http://members.gnn.com/GRMorton/dmd.htm