I should have from the very outset once again restated my
oft-repeated appreciation of your attempts to relate evolutionary
theory to a literal reading of the Bible. I do not always agree
with how you do it, but I do agree with you trying to do it!
On Thu, 01 Jan 1998 14:38:14 -0600, Glenn Morton wrote:
[...]
GM>At 10:00 PM 1/1/98 +0800, Stephen Jones wrote:
>SJ>There are a few problems with your chromosomal fusion theory. First,
>>if 2 chromosomes out of the apes 48 were fused, that would leave 47
>>chromosomes, not 46. Are you advocating two 2-way fusions or one
>>3-way fusion?
GM>I should have said 2 chromosome pairs fused.
Yes. Perhaps you need to change your web page and your book? Your web
page (last I looked) says that there was only *one* fusion of one
man's chromosome, ie. no. 2.
"The apes have 48 chromosomes; we have 46 (Johanson and Edey, p.
138, 275). If we arose from the apes, (as I believe we did) there
must have been a chromosomal fusion (there are also other
differences like inversions of certain segments etc). The data
clearly shows that it man's chromosome 2 is the combination of two
ape chromosomes. The banding in chromosome 2 are identical to the
banding in 2 ape chromosomes. (Yunis and Prakash, 1982, p. 1526)"
(Morton G.R., "A Theory for Creationists", DMD Publishing Co., 1996,
http://members.gnn.com/GRMorton/synop.htm)
Thanks for the reference. BTW, Yunis and Prakash do not say that
"the banding in chromosome 2 are *identical* to the banding in 2 ape
chromosomes", just that they are "similar":
"Evidence for a common ancestor of man and chimpanzee also comes from
chromosome 2, since human chromosome 2 is most simply explained by
telomeric fusion of a chimpanzee-like 2p chromosome and a 2q
chromosome similar to that of chimpanzee and gorilla." (Yunis J.J.
& Prakash O., "The Origin of Man: A Chromosomal Pictorial Legacy,"
Science, Vol. 215, No. 4539, March 1982, p1529).
In my daughter's university-level Genetics textbook, it also says
that the human chromosome 2 and two ape chromosomes are "similar",
but not "identical":
"A. D. Stock compared the banded chromosomes of members of the two
species...and noted the following structural differences: 1.
Chromosome 2 in H. sapiens is long and submetacentric, but is
comparable with two acrocentric chromosomes in P. troglodytes. When
these two chromosomes of P. troglodytes are fused together near the
centromere on the short arm of one chromosome and near the telomere
of the short arm of the other, a chromosome similar to H. sapiens
chromosome 2 is produced....Chimpanzee chromosomes compared with
human chromosomes. Both species have the same total number if two
chimpanzee acrocentrics are joined to correspond with Homo No. 2."
(Gardner E.J, et. al., "Principles of Genetics", 1991, pp506-507).
Gardner has a picture of the above chromosomes and it is obvious that
while very similar, they are not identical. Even Yunis J.J. &
Prakash's picture on p1526, and their diagram on p1527 shows that the
two chimp chromosomes 2p and 2q, joined together would be longer than
the fused human chromosome.
Having said that, I agree that from the evidence presented, man's
chromosome 2 appears to be the result of combination of two ape
chromosomes:
"Chimpanzees (Pan troglodytes) and human beings (Homo sapiens) are
placed taxonomically in different genera, Pan and Homo, respectively.
These species are much alike in anatomical and physiological features
as well as in DNA and protein composition. Comparisons of
chromosomes show basic similarities with a few superimposed
structural rearrangements. The overall number of chromosomes is
comparable (46 for Homo, 48 for Pan). Homologous pairs can be
identified, and general chromosome structure can be matched band for
band between the pairs. Two acrocentrics in P. troglodytes have the
same bands as one submetacentric in H. sapiens, to make the
equivalent of 46 in both species." (Gardner, 1991, p506).
Yunis & Prakash's excellent article is carefully and conservatively
argued and for me settles decisively the issue of man's common
ancestry with "a progenitor of chimpanzee and man" (Yunis & Prakash,
p1525). I thank you for drawing it to my attention.
I have no problem if God fused an ape's two chromosomes but then I am
a Progressive (Mediate) Creationist, who maintains that God may have
supernaturally intervened at strategic points in the history of
life. But it seems a bit inconsistent for you, a Theistic
Evolutionist, to maintain that God fused only chromosome 2, but left
the other chromosome to change by natural mechanisms. If the other
chromosomes can change by natural mechanisms, why can't chromosome
2?
But both Yunis & Prakash and Gardner point out that in addition to
chromosome 2 there are also other significant chromosomal differences
between chimps and and human, specifically in chromosomes 1, 4, 5, 8,
9, 12, 17, 18:
"2. Chromosomes 4, 5, 9, 12, 17, and 18 of the two species each
differ by a single pericentric inversion.
3. A probable pericentric inversion distinguishes chromosome 8 of the
two species.
4. Chromosomes 1 and 9 of the two species have small, special
differences in heterochromatin content."
(Gardner, 1991, p507)
If God was required to supernaturally fuse chromosome 2, why was He
not required to supernaturally invert and translocate the other 8
chromosomes.
Also, chromosome fusion is known to have occurred in monkeys, for
example:
"The African green monkey has a total of 2n = 60 biarmed
chromosomes (120 arms). These chromosomes were arranged in four
morphological groups corresponding with those of the rhesus
monkey: A: 11 pairs of subtelocentric; B: 12 pairs of medium to small
submetacentrics of varying lengths; C: 5 pairs of small metacentrics
and submetacentrics that appeared identical with group C of rhesus;
and D: 1 pair of small subtelocentrics with the secondary constriction
in the long arm. The long arm is homologous with the short arm of
rhesus D chromosomes....When the chromosomes of rhesus and the
African green monkey were compared...groups B and C and sex
chromosomes had matching elements in the karyotypes of the African
green and rhesus. The group A chromosomes in the two species were
different, but matching parts were found when chromosomes were
compared side by side. Some places that did not fit contained
constitutive heterochromatin. When excess heterochromatin was
trimmed from the African green monkey chromosomes, and the
euchromatin parts remaining on acrocentrics were fused, a nearly
perfect fit between the two karyotypes was obtained. The main
differences between the chromosomes of the two monkey species
were (1) amount and distribution of heterochromatin and (2)
translocations. Translocations were whole-arm fusions of centromere
to telomere that reduced three arms into two." (Gardner, 1991,
pp507-508)
To be consistent, would you not also have to claim that God
supernaturally intervened in creating by chromosome fusion of the
Rhesus Monkey from it's last common ancestor with the African Green
Monkey? Otherwise, if monkeys can have chromosomal fusions and
survive as a new species, why cannot apes?
Indeed, you claim in your web page that you can "account for the
origin of Adam and Eve by means of evolution and yet still have the
Biblical account be true:
"The origin of man. This is the tricky place. Everybody says that
it is impossible to account for the origin of Adam and Eve by means
of evolution and yet still have the Biblical account be true (Wells,
1961, p. 777; Whitcomb and Morris, 1961, p. 473; Davidheiser, 1969,
p. 168-169). ...This is false. Christians have not put enough
effort into solving this problem. Here is what the evidence says..."
Your solution does not "account for the origin of Adam and Eve by
means of evolution" at all. Supernatural intervention by God is not
evolution-it is creation! The whole point of evolution is that it is
claimed to be a way of obtaining design by a purposeless, natural
process, *without* the intervention of a Creator:
"The diversity of life on earth is the outcome of evolution: an
unsupervised, impersonal, unpredictable and natural process of
temporal descent with genetic modification that is affected by
natural selection, chance, historical contingencies and changing
environments." (National Association of Biology Teachers, 1995
Statement on Teaching Evolution, in Johnson P.E., "Defeating
Darwinism by Opening Minds"1997, pp15-16)
GM>The human has 46 chromsomes arranged in 23 pairs. The apes have
>48 chromosomes arranged in 24 pair. Two pair fusing gives 23 pair
>left and thus 46 chromosomes. By the way you can see the remarkable
>similarities between our chromosomes and the apes chromosomes in the
>article Jorge J. Yunis and Om Prakash, "The Origin of Man: A
>CHromosomal Pictorial Legacy," Science March 1982, p. 1525.
Of course, the above applies to *modern* humans. Your 5.5 mya Flood
theory is that Adam was not a modern human but either a Homo habilis
or Australopithecus:
"The only way to fit the scriptural account with the scientific
observations is to have Adam and Eve be Homo habilis or
Australopithecus." (Morton G.R., "A Theory for Creationists", DMD
Publishing Co., 1996, http://members.gnn.com/GRMorton/synop.htm)
There is AFAIK no way of knowing whether Homo habilis or
Australopithecus had 46 chromosomes or 48. It might be that Homo
habilis did, I doubt that a member of a different genus like
Australopithecus had 46 chromosomes. Yunis and Prakash's
diagram on p1528 shows the change to chromosomal 2 as ocurring
well after the chimpanzee split, which was about 5 million years
ago.
>SJ>Secondly, since the adult human body contains 100 trillion cells
>>(Stringer C., & McKie R., "African Exodus", 1997, p117), each with
>>the same number chromosomes, are you claiming that God performed
>>not one chromosomal fusion in this ape but 100 trillion?
GM>Stephen, Stephen, you forget that man starts with a single cell, a
>fertilized egg. If the fusion happens here, then it will be in all the 100
>trillion cells derived from that egg. What kind of biology do they teach
>down in Australia?
I didn't "forget". I was trying to draw you out, and I succeeded!
Your web page says that Adam was a "still born" whom God "fixed":
"During this time, there was among the physical ancestor of man a
very rare mutation -- a chromosomal fusion. But this error was
almost always fatal. God took one of these creatures, a still born,
fixed him, and blew his breath into him..." (Morton G.R., "A Theory
for Creationists", DMD Publishing Co., 1996,
http://members.gnn.com/GRMorton/synop.htm)
This seems to imply that God "fixed" Adam, ie. carried out the
chromosomal fusion, *after* Adam was delivered still-born. Now you
are saying the fusion took place when Adam was "a single cell". Which
is it to be?
>SJ>Third, the genetic difference between man and ape is much wider
>>jthan ust a chromosomal fusion: "The genetic differences between
>>humans and chimps are minor, but they include at least ten large
inversions and translocations." (Gould S.J., "Ever Since Darwin",
>>1977, p55).
GM>Yes and there has been 5 million years for these things to occur.
According to your 5.5 mya Mediterranean Flood theory, these things
must have occurred *before* 5 million years ago:
"I will make a suggestion that the place Genesis 2 is talking about
is the Mediterranean basin when it was emptied 5.5 million years
ago." (Morton G.R., "A Theory for Creationists", 1996,
http://members.gnn.com/GRMorton/dmd.htm)
GM>And an inversion is merely the turning of a region of a chromosome
>upside down. The material inside the inversion is still quite
>similar to that of the Chimp.
Agreed that it is the "material inside the inversion" that is more
important. Gardner says the important thing is the chromosome
*bands*, not their number:
"When chromosome bands are compared and homologies are identified, a
close relationship between the two species can be established. In
this comparison, at the species level, chromosome morphology is a
measure of phylogenetic change. Chromosome number, on the other
hand, depends on a more superficial "packaging" process and does not
represent a basic criterion for relationship. In this example (Fig.
18.25), one near centric change has made a difference in number,
while the basic chromosome units are essentially homologous."
(Gardner, 1991, p507)
But this seems to defeats your whole argument for the essential
difference between chimp and man being a fused chromosome 2. If the
material inside the chromosomes is of greater importance, and the
location of lesser importance, then why your emphasis on this one
fused chromosome?
God bless.
Steve
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Stephen E (Steve) Jones ,--_|\ sejones@ibm.net
3 Hawker Avenue / Oz \ Steve.Jones@health.wa.gov.au
Warwick 6024 ->*_,--\_/ Phone +61 8 9448 7439
Perth, West Australia v "Test everything." (1Thess 5:21)
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