Subject: Re: Evolution Challange, 2nd try
Date: Nov 22 22:21:28 1998
From: Mark Egger - megger at home.com


Responses to Mr. Spencer's points (which are in quotation marks) follow below:

>"1.The mutation must be non-lethal ( perhaps 1 chance out of
10000 or more )".

Where does this "math" come from? Consider for a moment the number of
meiotic divisions in each individul during its lifetime x the number of
individuals of a given species x the number of generations in as short a
period as 1000 years, and you get lots of opportunity for all sorts of
mutations, both lethal & non-lethal, even in organisms with long generation
times; moreover, lethal mutations in homozygous form may confer valuable
characteristics in heterozygotes, as in sickle cell anemia. Finally, a
mutation need only be SLIGHTLY beficial at the moment of its origin to
confer selectional advantage (e.g., a photosensitive cell that can
distinguish only dark from light is a first step towards an eye), and it
only HAS to occur once in order to be favored and passed on.

"2.The mutation must be genetically dominant ( 1 chance out of
2  or more )."

Nonsense. A useful mutation or even one that may be neutral at the time of
its inception can be passed on and maintained in heterozygotes, as a
recessive trait, in a multiple allele system, or in a multi-gene complex.


"3.The mutation must make the individual more likely to survive
and reproduce ( ? odds )."

Sure! That's what it's all about! It seems quite obvious to me that the
"odds" of a favorable mutation "surviving and reproducing" are quite high
-- that's precisely what I mean by DIRECTIONAL (not directED) selection!


"4.The mutation must also make its offspring ( who have various
genetic makeups ) more likely to survive and reproduce.(? odds)"

As it surely does in those offspring to whom the new mutation is passed!
Again, the "odds" are very high! By definition, a favorable mutation is
more likely to confer fitness and is more likely to survive.

"5.This process must be repeated many times within the genetic
characteristic that is being directionally changed before a new species
would be defined."

Untrue. It has been demonstrated in vascular plants that changes in one to
a few alleles can have drastic effects on the phenotype and that other
genetic events, such as polyploidy can, in effect, bring about speciation
in a single generation! Rapid speciation is documented in numerous taxa
throughout the phyla. In birds, relatively minor plummage variations and
shifts in vocal patterns (which are genetically-based) have led to rapid
speciation, not to mention an expansion of the ABA list! (e.g. screech
owls, "blue" jays, numerous warbler pairs, tanagers, orioles etc, etc.

"This must happen in an environment (consider all the factors that
can change in this environment) that continuously favors the direction of
this change during thousands or millions of years of time."

Again, nonsense! The fitness of any particular genetic shift is, indeed,
tested by changing environments, but that doesn't nullify the validity of
the process itself -- in fact a changing environment is an integral
component of evolutionary change! The FACT that we have an extensive and
ever-growing fossil record DOCUMENTING evolutionary change indicates that,
while many (most) genetic novelties were ended by one environmental or
stochastic event or another, the process of evolution itself has succeeded
extremely well at diversifying into the billions of unique, non-hybridizing
genetic systems (species) we see today. A genetic change need only be
beneficial from one generation to the next in order to be selected for in
that generation.

"That is, assuming it is the environment and not an intelligence
that is directing this change.  An environment cannot direct a plan
for change since it has no "master-plan"; an intelligence could. 
Perhaps that intelligence would need to be called God."

Whatever you want to call it, it has been going on for 3.5+ billion years
and is going on as we speak. It is quite true that evolution has no
"master plan", other than getting any particular complex of genes on to the
next generation. I have no problem with that fact.

"Then we would need to find out if God is in the "DIRECTIONAL
selection of random mutations" business which puts us into theology - not
biology."

I'll agree with you on that point!

"6. Within simple life forms this process is much more likely to
happen and apparently does happen in viruses."

Oh, so evolution is granted to the little slimy things but couldn't
possibly apply to such advanced beings as ourselves or a protist or a bird
or a begonia... Of course, this is the chauvinism of the complex, the
self-important, and the generation-time impaired. The reason we see and
MUST admit the evolution of prokaryotes & viruses is that they have such a
short generation time. All you need is more time to observe the SAME
process in all living things -- it's all there in the fossil record...

"However, as the life form increases in complexity the odds of it
producing a new species is extremely unlikely."

Sorry, but I completely disagree with this statement and can see neither
factual nor logical support for it.



- Mark Egger
9521-49th Ave. NE
Seattle, WA 98115-2627

megger at home.com