I will order that article today. But I still don't know that I buy this
figure and here is why 2^50 =1.1 x 10^15. If all the cells along the line
divide the same number of times, and produced cells the size of the sperm, 60
microns in diameter (30 in radius) that means that in the first 20 years of
my life, while awaiting sexual maturity, I must make and slough off a cube of
cells 5 meters on an edge. Notice I used the size of a sperm which is among
the smallest of human cells. If I had used the egg, which is 195,000 times
larger the result for the women would be a cube 10^14 meters on a side.
This leads to a logical contradiction. 1 .Either the cells don't divide 50
times (that quote is rather old, is there a newer value? 2. all descendent
cells do not divide at the same rate (which is true in the case of sperm vs
somatic cells).
If 2 is the correct option, after how many divisions do sperm/egg lines
become separate and how many divisions do they undergo before sexual maturity
is reached.. This is necessary to know for the calculation of how much mass
is created by such division.
Also, what is the case with the man is not so with the woman. I recall that
a female is born with about 40,000 eggs and that is all she is going to have.
Her line gives quite a different answer.
I did find in Scott F.Gilbert's _Developmental Biology_, 1991 p. 790-791)
the following information in regards to a mouse. The germ cells are first
found in a 7 day embryo in a region of 8 cells. By day 12 these cells have
migrated to the developing left and right sex organ and have "proliferated"
to 2500-5000 cells. Which represents about 9 divisions for the 8 cells. The
question I can't answer is how many divisions did it take to get to the 7 day
embryo?
Can anyone shed some light on the issue of how many divisions or how this
paradox is to be resolved?
Walter wrote:
>So in this post Glenn has begun altering his argument. Like this:
I replied:
:>Now, I agree that you can get a mutation in this
:>gene, but unless I am mistaken, most alleles are quite different in :>their
sequence from one another. If all alleles were only 10 :>substitutions
different from each other, then you might have a case, :>but if the allelic
sequences are substantially different, then there has :>not been enough time
to generate enough substitutions in this given :>1000 unit long sequence.
Walter replied:
>That is a different argument than he made previously. Now he is >focusing
on the *number* of mutations within a given allele, and he is >focusing on
substitutions. Neither of those matters was in his >previous argument. The
issue was not substitutions, instead the issue >was the *presence* of 59
versions a given gene (known as alleles).
>
No, Walter, this is not a different argument. Perhaps you misunderstood. This
has always been the point. At each given location on the genome there is
more variability than we should expect if there was a flood with its ensuing
genetic bottleneck anytime in the past 200,000 years.
Historically, as far as we can look back, Africans have looked like
Africans. (See Frank M. Snowden, Jr., Blacks in Antiquity, [Cambridge,Mass:
Harvard Univ. Press, 1970), There are lots of vases, statues etc depicting
people with subsaharan African features from 500 B. C. on. In Egypt, the
25th dynasty of Egypt beginning in 751 B.C. was the conquest of Egypt by the
Meroeites who were black Africans from further south along the Nile. They
successfully ran the kingdom until 663 B.C.(see Snowden p. 113-115)
Now, the point is that a lot of the traits which make Africans, Africans
and Europeans, Europeans are due to the different alleles we are dealt. If
the flood was when the YEC's say, approx 3300 B.C. (See Gerald Aardsma, "When
the Exodus Happened", in Robert Walsh, editor, Proc.3rd Int. Conf. on
Creationism, p. 15), it gives you 2500 years in which to develop all those
alleles that Africans and Europeans do not share. If evolution occurs that
rapidly, why do we not see it occuring in either the general population or in
isolated communities over historical times, say since the Roman Empire?
Walter wrote:
>Glenn has not shown any problem with the rapid production of genetic
variation. On the contrary, he implied that a lower mutation would be
sufficient. So he then took a double step and suggested a MUCH lower
mutation rate -- in an attempt to create ("exasperate") the problem for
YEC's. <<
I'm sorry but I do not follow you here.
Walter wrote:
>Glenn forgets that a much lower mutation rate aggravates certain problems
for evolutionists. The maximum plausible rates of beneficial substitution
and neutral substitution are already too slow for evolutionists (see my book
or my posts of several months ago on Haldane' s Dilemma). Those rates are
tied to, and limited by, the mutation rate. A lower mutation rate slows
things down and makes those problems worse. So when Glenn suggests a much
lower mutation rate, he is really playing with a two edged sword. I urge
caution. <<
Even if I grant your thesis that lower mutation rates cause problems for
evolutionists (which I don't) the topic that started this was the problem the
YEC's have explaining genetic diversity! Please stay on topic. Even if you
are correct here, another problem which the evolutionists may have does not
excuse or eliminate the problem the YEC's still have!
Walter wrote:
>Glenn is mistaken about my argument, which does not require that neighbors
pass their genes around. In fact, my argument holds even for an asexual
population, where no genes whatever are passed between individuals. My
argument is exceedingly simple. Start with 2 million copies of a gene,
replicate those through 200 generations. You would expect 40000 mutations to
that gene.
Perhaps Glenn might complain that I started with a population size of one
million. But the human population has been that large for virtually all (if
not all) of 200 generations, and typically has been much greater.<<
But Noah and his family did not start with two million copies of a gene at
least as far as reproduction is concered. They started with 10 alleles max
at each location because as Jim Blake noted and I did earlier, there are only
5 independent people on the ark. You are correct that I will complain about
that point
Walter wrote:
"I don't want this to turn into a debate about rates of population growth
back several thousand years ago. So let me add a modern perspective that is
irrefutable. Take a population of one billion people (that's 2 billion
copies of a given gene). In merely THREE generations that gene would
receive: 2 billion x 3 / 10000 = 600,000 new mutations. Glenn only asked
for 59! There is nothing historically to quibble with here, as this
argument used known sizes of modern populations. When Glenn asks for
"genetic variation", I can supply it in abundance. <<
That won't explain the situation at all. There are three problems here.
First there is a little matter of collecting all those mutations into one
segment of the population. This is why the mathematics must be done along
generational lines (through time as opposed to your way through space at a
given time). It matters not that some guy in Siberia gets a gene for kinky
hair, someone in South America gets a gene for Steatopygy, and some guy in
Europe gets a gene for a broad nose. If they are not collected together, you
do not have an african (or at least one among many types of africans).
Secondly, you are avoiding the issue of how multiple mutations can be
accumulated in the same 1000-unit long string of DNA.. Alleles are not always
simply a 1 position change in the sequence.This is another reason the math
must be done in a chronologically linear fashion rather than in a spatially
flat fashion.Alleles often have many more. Six hundred thousand, one-locus
mutations to a genetic code do not make for 600,000 alleles. They might just
as well make for 600,000 fetus's which failed to develop. And it is a well
known fact that large numbers of fertilized eggs spontaneously miscarry or
fail to implant.
Third, I do not think (although am open to correction from someone like
Steve Clark or Steve Fawl who is familiar with the molecular data) ) that we
see the type of genetic variation which you envision here in molecular
studies of various animals. Your model of allele formation would require
massive, massive numbers of alleles. I just don't think we see that. Can you
provide documentation?
glenn