It is similar Sewell-Wright's adaptive landscape (I am familiar with his
work). The only difference is that it is applied to the DNA, not to
fitness. It is really a mapping of the paths that a DNA sequence can move
in. Each DNA sequence represents a point in sequence space (or phase
space) and this point either produces a living being or it doesn't. So it
the fitness I am mapping is only the fitness of viability. Some sequences
give rise to dead animals and aborted fetus'. These are points in phase
space that are very unfit. I view the only fitness as a 2-choice, an on-off
switch, alive or dead. THis sequence allows the owner to live, that
sequence causes the owner to die. So, as far as I am concerned, DNA phase
space makes only a choice between viability and non viability. Which is a
simplified adaptive landscape. Because the DNA phase space is billion
dimensional, so the real adaptive landscape is billion dimensional. To
display it as a 2d surface (which is the way an adaptive landscape is most
often displayed), is a mistake or a simplification for educational
purposes. The real landscape is billions of dimension. That is why life is
so complex!
>
>Adaptive landscapes have been used to illustrate changes in phenotypes
>*within* lineages. It predicts, for instance, that the probability for a
>population to go from one peak to another higher peak depends on the
>"deepness" of the valley separating them, and can be attained by the
>influence of factors such as genetic drift.
In higher dimensional spaces the valleys can be circumvented by to going or
traveling in a different dimension and thus avoiding the problem areas
entirely. Go look up a moibus strip. It is a 2 d surface which has only
one side. A Klein bottle is a 3d bottle with only one side. When you go
to higher dimensions, connections like the moibus strip (a very simple
object) and or Klein bottle are multiplied thousands upon thousands of
times and connectivity is more weird. So paths exist in the
multidimensiona DNA phase space world that we can't even visualize, but
these connections allow species to evolve from one cavern of viability to
another.
>
>However, speciation events are not usually caused by processes such as the
>ones depicted in adaptive landscapes. Currently the process believed to be
>the most common in generating new species is called allopatric speciation.
>What happens is simply a barrier that prevent gene flow between two
>populations that previously were interconnected, *regardless* of the
>configuration of the adaptive landscapes. Reproductive isolation is simply
>the by-product of differences in selective environments, population sizes
>(genetic drift) and things like that. The barrier is the most important
>factor, otherwise gene flow would homogenize the differences among
>populations.
>
>Now, it seems that you are suggesting that the path taken by speciation
>events could be previously determined by the genome of the mother species.
You are correct that speciation is much more complex than this. My view is
NOT per se a theory of speciation, but merely a recognition of the fact
that as a species evolves, it's DNA sequesnce is altered. This means that
the individuals which make up the incipient species are moving in sequence
space (phase space) to some other region. The DNA path they take must
allow for viable organisms. If the alterations in their DNA caused death,
there could be no speciation. So the path taken through this sequence space
must be a tunnel of viability.
Here is where my theology enters. I believe that God designed the DNA phase
spaces and thus the paths allowed in phase space are determined by him.
This is like watching a train. The train can go anywhere on the landscape
as long as it is on the railroad tracks. And God having designed these
spaces, knows that given enough time, mankind would arise. In this way one
can retain the classical providence, omnipotence and omniscience with
evolution.
>It seems to me that speciation events are much more complex than that, and
>much of it is determined outside the influence of the DNA itself. If God
>has directed speciation events, his influence must be much more complex
>than just influencing mutation rates or anything like that. MOreover, if
>God did such influences in the lineages leading to us, would it be
>possible for us to detect that influence with scientific methods?
As I mentioned above, the only influence that the DNA plays is as an on-off
switch. You are either alive or your aren't. If you are alive, then your
DNA lies in a cavern of viability, if not, you are not you are dead.
glenn
Foundation, Fall and Flood
Adam, Apes and Anthropology
http://www.flash.net/~mortongr/dmd.htm
Lots of information on creation/evolution