Reflectorites
On Tue, 10 Oct 2000 09:35:55 EDT, Huxter4441@aol.com wrote:
[...]
>HX>What about nuclear DNA mutation rates?
SJ>It was the New Scientist article (based on a SCIENCE journal report) that
>I quoted so if Huxter has any questions about the use of mtDNA rather
>than nuclear DNA his dispute is with those journals.
[...]
HX>I have no dispute, I was just curious if any mention of nuclear DNA mutation
>rates had been mentioned.
I posted the whole article, so if by "What about nuclear DNA mutation
rates?" Huxter was "just curious if any mention of nuclear DNA mutation
rates had been mentioned" he could have read it for himself!
HX>It appears that 1) they were not and 2) you are
>unfamiliar with the concept of using nuclear DNA in molecular clock
>calculations. Do you know why mtDNA is preferrentially used in such studies?
Again, I was just posting A "New Scientist article (based on a SCIENCE
journal report)". If Huxter thinks that "they" (i.e. the authors of the
New Scientist and SCIENCE articles) were "unfamiliar with the concept of
using nuclear DNA in molecular clock calculations" he should take it up
with them.
SJ>My understanding is that the molecular clock hypothesis is based on the
>*neutral* mutation rate. Mitochondrial DNA is therefore used instead of
>nuclear DNA because mtDNA is thought to be selectively neutral since it
>does not code for any phenotypical features.
HX>Actually, there isn't really "a" molecular clock hypothesis, at least not
>insofar as it focuses on mt or nuclear DNA. The MCH was originally aimed at
>proteins, way back in the early 1970s, and nuclear DNA has been used as far
>back as the late 1980s (if not sooner). Your understanding is apparently
>limited.
I am a layman. There is no "apparently" about it. My "understanding" *is*
"limited"!
But OTOH, how do I know that someone who goes under the
*pseudonym* "Huxter4441" knows what *he* (or she) is talking about?
Perhaps Huxter can tell us who he/she is, and what his/her qualifications
are, so we can judge his/her ability speak authoritatively in this or any field?
SJ>But if Huxter knows of any molecular clock studies based on "nuclear DNA
>mutation rates", perhaps he can post it to the List?
HX>Sure Steve. Why, doing a simple medline search produced 8 hits on Primates
>alone. A sampling:
[...]
Thanks to Huxter, but what I mean was post the *details*, in particular
how it relates to the article I posted about mtDNA's clock.
HX>There are others, and I know of at least two more that will be coming out
>within a few months looking specifically at humans. There is a review paper
>that compares nuclear DNA molecular clock dates with dates inferred from the
>fossil record and there is a remarkable congruence between the two.
That is not "remarkable" at all, since the molecular clock was originally
calibrated by the fossil record!
The interesting thing will be if there is any major differences between the
mtDNA and nuclear DNA molecular clocks. Or even between different
nuclear DNA molecular clocks.
HX>I can dig up the ref if you'd like.
What does it matter what *I* "like"? If Huxter wants to post anything, let
him post it.
But if the "nuclear DNA molecular clock dates" disagrees with the mtDNA
dates, then someone has a problem!
>HX>Do we just ignore that much larger amount of information
SJ>See above. It was the above scientific journals who Huxter is claiming is
>"ignore that much larger amount of information". I just posted what New
>Scientist said.
[...]
HX>I see. I thought maybe you could formulate your own opinion. I didn't
>realize that you were simply a 'reporter' for this list, busily scribbling
>down and quoting what others have written...
I am *touched* that Huxter is more interested in my "own opinion" rather
than those dumb old scientific journals! :-)
SJ>And anyway, what "larger amount of information" is that exactly?
[...]
HX>Surely you recognize that the nuclear genome is many orders of magnitude
>larger than the mitochondrial genome?
Huxter is right on that one.
But that was not what Huxter said. It does not follow that just because "the
nuclear genome is many orders of magnitude larger than the mitochondrial
genome" there will be a "larger amount of information" regarding
*molecular clock* studies.
As I said before, the problem as I understand it, with any part of the
nuclear genome that it is thought to be more likely than the mitochondrial
genome to have been affected by natural selection.
>HX>because if we put a certain spin on reality,
SJ>I am glad Huxter said "we"! Claims about putting a "spin on reality" cut
>both ways.
[...]
HX>It is a shame you cut out the context of my quote.
But of *course* I did - I am a creationist remember! :-)
>HX>I understand creationists
>of all stripes have a distinct tendancy to do so such that a statement can
>appear to mean something it originally did not.
See! :-)
But seriously, if Huxter thinks I have "cut out the context of" his "quote"
he can repost it and say why he thinks I did.
>HX>the YEWC framework looks peachy?
SJ>What is the "YEWC framework"?
[...]
HX>It is a typo. You see, on my keyboard, the 'w' and the 'e' are next to each
>other, and when typing hurriedly one can often hit more than one key at a
>time. Not doing a spell check allows them to slip through. But I'm glad you
>paid such close attention.
So my "close attention" has foiled Huxter's attempt to found a new school
of creationists, the YEWCs! :-)
SJ>If it is anything to do with YEC then Huxter is barking up the wrong tree
>on two counts:
>
>1. I am an *old*-Earth creationist; and
[...]
HX>Well, pardon me. Either way, it seems that your 'concerns' about the mtDNA
>molecular clock are a bit on the weak side.
What "`concerns'" were those exactly?
SJ>2. the issue is the antiquity of *man* not the antiquity of the Earth.
[...]
HX>Same thing.
Not really. YECs believe the days of Genesis 1 are literal 24-hour periods,
so to YECs the "antiquity of the Earth" is effectively the same as the
"antiquity of man".
But OECs do not believe the days of Genesis 1 are literal 24-hour periods,
so to OECs the "antiquity of the Earth" and the "antiquity of man" are two
entirely separate issues.
Steve
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"Biology is the study of complicated things that give the appearance of
having been designed for a purpose." (Dawkins R., "The Blind
Watchmaker," [1986], Penguin: London, 1991, reprint, p1)
Stephen E. Jones | Ph. +61 8 9448 7439 | http://www.iinet.net.au/~sejones
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