You wrote:
>Glenn has, in the past, informed us that "Mitochondrial Eve" is dead. I
>can assure you the the reports of her death have been greatly
>exaggerated. The following link briefly summarizes a bit of the latest
>research on mtDNA sequences:
Actually I don't think I said Eve was dead. I searched my letters back to
1998 and couldn't find where I said Eve was dead but I did get a computer
stolen and I have lost a few posts during the move to Houston. What I said
(or at least remember saying) was that Eve was twice as old as a result of
the studies and to use mitochondrial Eve as a way to delimit humanity to
only modern mankind is wrong. And in the report that you cite, I did not
use the word 'dead'. I do want the record corrected. At the end of this
note I will attach the original work I wrote on those two investigations.
The reports I cited said that there was paternal input of DNA. There will
always be an Adam or Eve for each scrap of our DNA and the Adam and Eve
don't have to be the same person for each scrap.
>This article mentions that "because after conception only the egg's
>mitochondria survive, mtDNA forms a continuous thread running back
>through time through the maternal lineage." This is not strictly true.
>It has been demonstrated that some mtDNA can enter the egg with the
>sperm. But.....
>
>I quoted this particular sentence because of a recent post by Glenn
>regarding two studies published in the Proceeding of the National
>Academy of Science. This research seemed to indicate that there might
>be some paternal contribution to the mtDNA lineage. These studies are
>very equivocal. There has been at least one response in Science
>disputing these reports. I do not have the reference at my fingertip,
>but I have a copy of the article here on my desk somewhere (buried under
>textbooks and homework.)
When you find the reference I would like to get it. And I would say that
the evidence from Vanuatu is much less equivocal than you think. I would
point out that that there are known cases of people with multiple copies of
mtDNA. The Grand Duke ofRussia was one such person with two distinct
lineages of mtDNA in the same person. Given that he didn't have two
mothers, I would suggest that the only reasonable explanation is that one
copy came from papa!
see Pavel L. Ivanov et al, "Mitochondrial DNA Sequence Heteroplasmy in the
Grand Duke of Russia Georgij Romanov establishes the Authenticity of the
Remains of Tsar Nicholas II," Nature Genetics, 12, April 1996, p. 417-420,
p. 417
see also Barbara Petri, Arndt von Haeseler and Svante Paabo, "Extreme
Sequence Heteroplasmy in Bat Mitochondrial DNA," Biol. Chem., 377:661-667,
p. 661
and,
Douglas C. Wallace, "Mitochondrial DNA in Aging and Disease," Scientific
American, August, 1997, pp 40-47, p. 42
>
>In addition, I have also been in contact with an acquaintance, a
>biochemist and microbiologist who is doing research in the mitochondrial
>DNA. He has told me about an incredible biochemical system which seems
>to specifically target paternal mtDNA and destroys it within the first
>few cleavages of the egg. It seems there is a group of biochemists who
>get all excited when talking about something called Ubiquitin-Mediated
>Targeted Protein Degradation. Apparently this is a hot new area of
>research. (I hope the biologists on the list will help me out here if I
>am too off base.)
I would only note that no mechanism in biology is 100% effective and thus
the occasional input of paternal DNA would be enough to mess up the dating
of Eve as I suggested. But, I didn't say Eve was dead.
>At any rate, the biologists I have talked to do not give great credence
>to this report about paternal mtDNA.
>
I would like to hear their explanation of how the Grand Duke had two
mothers in order to have two different types of mtDNA.
Here are other species examples of heteroplasmy:
"Mitochondrial heteroplasmy, i.e. the coexistence within one individual of
two or more mitochondrial genomes (mtDNA) that differ in primary structure,
has been observed in a number of species, including eutherian mammals such
as rabbit, monkey, American evening bat, pig, elephant seal, and shrew as
well as marsupials and monotremes. In all these cases, the mitochondrial
genomes within an individual differ in size due to variable copy number of
repeated sequences located in the control region, which encodes no
structural genes but contains sequences necessary for the replication and
transcription of the mitochondrial genome. In contrast, heteroplasmy
involving genomes that differ by basse substitutions hs been reported to be
virtually absent in humans except in diseases caused by mitochondrial
mutations. However, recently, a number of cases have been reported where
heteroplasmy occurs in healthy humans. Similarly, substituional differences
between genomes within a lineage of cows have been shown to occur.
Furthermore, in some non-mammalian speciies, e.g. mussel and anchovy,
heteroplasmy with high levels of within-individual seqeunce divergence
exists, and in those cases biparental inheritance of mitochondrial DNA has
been inferred or shown to be the fuctional origin of the heteroplasmy.
Here we show that the coesixtence within an individual of several different
mitochondrial genomes, carrying many substitutional differences, is not the
exception but the rule in bats. In other mammals, including hmans, a
similar situation albeit to a lesser extent, may exist." ~ Barbara Petri,
Arndt von Haeseler and Svante Paabo, "Extreme Sequence Heteroplasmy in Bat
Mitochondrial DNA," Biol. Chem., 377:661-667, p. 661
**
"Thus, divergences between molecules within one individual were of the same
magnitude as the divergences between molecules from any two animals in
different European populations." ~ Barbara Petri, Arndt von Haeseler and
Svante Paabo, "Extreme Sequence Heteroplasmy in Bat Mitochondrial DNA,"
Biol. Chem., 377:661-667, p. 664
**
mtDNA
"The other possible source of heteroplasmy, paternal contribution, has been
demonstrated in mussels. However, in mammals paternal mitochondrial
contribution is at best very low. In humans, less than one out of 10000
mitochondrial DNA molecules stems from a putative paternal contribution." ~
Barbara Petri, Arndt von Haeseler and Svante Paabo, "Extreme Sequence
Heteroplasmy in Bat Mitochondrial DNA," Biol. Chem., 377:661-667, p. 665
My original post in which I didn't use the word 'dead'. For anyone who
cares to verify this, see:
http://www.calvin.edu/archive/asa/199905/0353.html
glenn
Foundation, Fall and Flood
Adam, Apes and Anthropology
http://www.flash.net/~mortongr/dmd.htm
Lots of information on creation/evolution