At 09:45 PM 10/20/98 -0700, Arthur V. Chadwick wrote:
>At 07:58 PM 10/20/98 -0500, Glenn wrote:
>>Evolutionary theory sure does use math. Have you never heard of population
>>dynamics, the logistics equation, Hardy-Weinberg, the equations of
>>chemistry, and others. I am sure that the biologists could do a better job
>>than I. The assertion that biology doesn't use math is ... well, wrong.
>
>Maybe so, Glenn, but have you ever examined the consequences of say, for
>example, Hardy Weinberg for evolution? A colleague of mine at Cal Tech
>told me one time that Hardy Weinberg was the death knell of evolutionary
>theory. For example when Arthur in his book on the Origin of Body Plans,
>wants to show how a mutation can be fixed in a population, he chooses a
>dominant mutation to work the math with, even though he admits that the
>probability of such a mutation is vanishingly small. Why? Because the
>equations dont produce the desired results when he uses the same parameters
>in Hardy Weinberg with a recessive mutation. It won't happen, so such
>things as founder effect had to be invented to make anything happen. But
>for it to happen in the founder population, the appropriate genes have to
>be there, and thr probability of that is also calculable, and is the same
>order as the pprobability for the fixing of the recessive mutation in the
>population. So the math that biologists do have doesn't always help
>evolutionary theory.
Having just read "how the Leopard Changed his spots" on vacation, (an
excellent book I would recommend to everyone as Brian Harper did a couple
of years ago which is why I bought it) I think that there is a difference
between how neoDarwinists believe evolution takes place and how it actually
occurs. I don't think that evolution ONLY occurs as an accumulation of
beneficial genes. It also is an alteration of the developmental program
which consists BOTH of DNA AND ENVIRONMENTAL INFORMATION.
Goodwin gives the example of the Mermaid's cap algae. This consists of a
single very large cell which has a cap at one end and a root-like
structure at the other with a stalk connecting the two. The cell nucleus is
in the rootlike portion. The thing looks something like a dacquari glass.
Goodwin writes:
"If an adult Acetabularia is cut in two by simply snipping through the
middle of the stalk, the lower (basal) part with the rhizoid and the
nucleus regenerates a new cap, while the part with the cap lives for
several weeks and then dies. Regeneration from the basal part takes place
by the same sequence of events that characterizes normal morphogenesis:
after the cut has healed with a new cell wall formed over the cut, a little
tip forms, grows and produces a series of whorls and then a cap." p. 90
"Suppose that the cap is cut off, along with the cap--it lives for a while
and then dies. And the basal part with the nucleus regenerates the whole
alga. What about the stalk? The expectation is certanly that it will
behave like the cap--live for a while , then die. And that is correct. but
what it does while it is alive is unexpected. It regenerates a cap! And it
does so in the usual way: healing at both ends, growing a tip where the cap
used to be, which produces whorls and then a new cap. Ocassionally,
regeneration occurs at the opposite end of the stalk, where the base used
to be, and very occasionally from both ends, the result being a stalk with
a cap at both ends. However, a part without a nucleus always dies
eventually. What are we to make of these intriguing observations?
"First, a nucleus is clearly necessary for the survival of the organism
and for the completion of the life cycle. It is equally clear that
morphogenesis occurs in the absence of a nucleus, so it is not the nucleus
itself that directs this process." p. 91
What was found is that if the Mermaid cap grew in water with little
calcium, no cap forms. So calcium is necessary for the expression of the
morphology. In this case, morphology gets its directions from both DNA and
the environment. This is a really different view. How does calcium work?
It seems that calcium weakens the cell wall and the cytoplasm bulges out at
such places. This causes the cell wall to release calcium from the stored
state in the cell further weakening the cell wall. This positive feedback
loop would destroy the cell if not opposed by other processes. But the
timing of these processes is controlled by physics and by genes. Change
those and you alter morphology.
What is interesting is that this process of DNA, nuclear products,
cytoplasm and environment operating in concert forms the morphology of the
being. Morphology often is involved in successful animals and morphology is
not totally under the control of the genes themselves. So, the
hardy-Weinberg law may not be an adequate description of how evolution is
driven. Gene frequencies are only part of the story.
Goodwin also gives an interesting example of lamarckian inheritance among
paramecium. on page 13.
fascinating book
glenn
Adam, Apes and Anthropology
Foundation, Fall and Flood
& lots of creation/evolution information
http://www.isource.net/~grmorton/dmd.htm