throop@cs.utexas.edu (David Throop) (12/08/90)
We've got Eve. Now what about Adam?
There has been a fair amount of coverage lately of the finding that
about 200,000 yrs ago, there was one woman who was the matrilineal
mother of us all. These studies have used analysis of mitochondrial
DNA, because it is inherited only matrilineally. Genetic drift studies
were used to gauge how far back this "Eve" lived.
[For those not familiar with these reports, this does not indicate
that there were no other women alive at that time. It does not indicate
that those other women have no surviving descendents. It indicates that
those other women have no descendents along purely matrilineal lines of
descent.]
What about finding the same for men? Isn't the Y chromosome the
analog of the mitochondrial DNA? It is passed entirely from the
father's side. Isn't the Y chromosome in my cells just a many-time
copy of my great^N-father's Y chromosome?
Shouldn't genetic drift analysis also be able to gauge how far back
it was that there lived a man who was the patrilineal father of us all?
Or has this already been done?
David Throopbryans@ux1.cso.uiuc.edu (Bryan Siegfried) (12/08/90)
throop@cs.utexas.edu (David Throop) writes: >about 200,000 yrs ago, there was one woman who was the matrilineal >mother of us all. These studies have used analysis of mitochondrial >DNA, because it is inherited only matrilineally. Genetic drift studies >were used to gauge how far back this "Eve" lived. ... > What about finding the same for men? Isn't the Y chromosome the >analog of the mitochondrial DNA? It is passed entirely from the >father's side. Isn't the Y chromosome in my cells just a many-time >copy of my great^N-father's Y chromosome? > Shouldn't genetic drift analysis also be able to gauge how far back >it was that there lived a man who was the patrilineal father of us all? > Or has this already been done? The Y chromosome is in the nucleus, and like most eukaryotic DNA (organelle DNA excepted), many mechanisms are present to protect the Y chromosome from being changed. Mitochondria have almost no mechanisms to maintain their genetic integrity. Over 200,000 years, the mitochondrial DNA will change enough for genetic drift studies to be done. However, in 200,000 years (a reasonable estimate for the Y-chromosome Adam), there would be very little change in the Y chromosome. With such little change, a similar genetic drift study wouldhave very little accuracy. __ Bryan Siegfried zig@uiuc.edu Biology and Economics at UIUC
davisd@beasley.CS.ORST.EDU (David M. Davis - Public Safety) (12/11/90)
I recall reading about a problem with this study. I can't recall what the problem was. If it was in the analysis or in the data but there was a problem. It is an interesting theory, (I saw the NOVA that talked about it.) davisd@ucs.orst.edu
sbishop@desire.wright.edu (12/11/90)
In article <22079@orstcs.CS.ORST.EDU>, davisd@beasley.CS.ORST.EDU (David M. Davis - Public Safety) writes: > > I recall reading about a problem with this study. I can't recall what the > problem was. If it was in the analysis or in the data but there was a > problem. It is an interesting theory, (I saw the NOVA that talked about it.) > > davisd@ucs.orst.edu The best book on the topic is _The Search for Eve_. It covers all the arguments on the subject very well. BTW, the main complaint is that using The Eve Theory, all other lines of humans around the world at that time are considered to have gone extinct. This doesn't do well with the 'bone' scientists since they see a definite pattern with the fossil bones through out that period and later on as to inheritance of certain characteristics.
gagen@bgsuvax.UUCP (kathleen gagen) (12/12/90)
From article <1990Dec8.014156.15393@ux1.cso.uiuc.edu>, by bryans@ux1.cso.uiuc.edu (Bryan Siegfried): > The Y chromosome is in the nucleus, and like most eukaryotic > DNA (organelle DNA excepted), many mechanisms are present to protect > the Y chromosome from being changed. Although many mecnanisms are present to protect the Y (and other) chromosomes from being changed, it (and they) can and do change. Mutations and chromosome rearrangements occure. There are, in fact genetic differences between men with respect to the genetic information contained on their Y chromosomes. One visable difference is the trait called "Hairy Pinea". This condition is characterized by the presence of hair on the earlobe. The gene for this trait is located on the short arm of the Y chromosome (that portion which is not homologous to the X). It is, therefore, inherited through the paternal line. > . However, in 200,000 years (a reasonable estimate for the > Y-chromosome Adam), there would be very little change in the Y chromosome. > With such little change, a similar genetic drift study wouldhave very > little accuracy. See above. --- Kathleen Pausic Gagen > Bryan Siegfried zig@uiuc.edu > Biology and Economics at UIUC
hrubin@pop.stat.purdue.edu (Herman Rubin) (12/12/90)
In article <1990Dec11.105612.2009@desire.wright.edu>, sbishop@desire.wright.edu writes: > In article <22079@orstcs.CS.ORST.EDU>, davisd@beasley.CS.ORST.EDU (David M. Davis - Public Safety) writes: > > > > I recall reading about a problem with this study. I can't recall what the > > problem was. If it was in the analysis or in the data but there was a > > problem. It is an interesting theory, (I saw the NOVA that talked about it.) > The best book on the topic is _The Search for Eve_. It covers all the > arguments on the subject very well. BTW, the main complaint is that using > The Eve Theory, all other lines of humans around the world at that time > are considered to have gone extinct. This doesn't do well with the 'bone' > scientists since they see a definite pattern with the fossil bones through > out that period and later on as to inheritance of certain characteristics. All of our mitochondrial ancestry comes from Eve. There is no other female at the time who contributes genetically in an unbroken female line. But this says nothing about contributions to our *chromosomal* inheritance. Because our chromosomes come from both parents, there is no comparable way of tracing their inheritance, except possibly for the portion of the Y chromosome coming from the father without crossover possibilities with X. This, if it could be carried out, would be the search for Adam. This exclusively male part of the Y chromosome is a very small part of the 46 human chromosomes. I do not know the relative contribution of the mitochondrial DNA. But it would definitely not be legitimate to say that the line of a woman is extinct if she only has sons, or the line of a man is extinct if he only has daughters. -- Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399 Phone: (317)494-6054 hrubin@l.cc.purdue.edu (Internet, bitnet) {purdue,pur-ee}!l.cc!hrubin(UUCP)
schumach@convex.com (Richard A. Schumacher) (12/21/90)
In <1990Dec11.105612.2009@desire.wright.edu> sbishop@desire.wright.edu writes: > BTW, the main complaint is that using >The Eve Theory, all other lines of humans around the world at that time >are considered to have gone extinct. This is a common misunderstanding. The "Eve theory" means only that there are no unbroken matrilineal lines going back to other females alive at the time of "Eve". Certainly any number of the other females alive at that time could have lving descendents, but only through a male descendent at some point so that their mitochondria were not passed along.
sbishop@desire.wright.edu (12/21/90)
In article <schumach.661737735@convex.convex.com>, schumach@convex.com (Richard A. Schumacher) writes: > In <1990Dec11.105612.2009@desire.wright.edu> sbishop@desire.wright.edu writes: >> BTW, the main complaint is that using >>The Eve Theory, all other lines of humans around the world at that time >>are considered to have gone extinct. > > This is a common misunderstanding. The "Eve theory" means only that there > are no unbroken matrilineal lines going back to other females alive at the > time of "Eve". Certainly any number of the other females alive at that time > could have lving descendents, but only through a male descendent at some > point so that their mitochondria were not passed along. That's right. I was not making myself clear. (A common failing__ ;) ) The best explanation is the one in _The Search For Eve_. Does a much better job of the arguments on both side than I ever could. There was some discussion in the book along these lines, but the main problem was that so very few matrilineal lines had survived.
baltuch@BINAH.CC.BRANDEIS.EDU (12/28/90)
hi:
by some sort of a coincidence, i posted a request for reliable
references for the search of "eve" or "eves" using mitochondrial
dna of existing humans on alt.origins (no Time magazine please!)
i thought i'd try here too. in particular i'd like to know something
about the methods involved and the assumptions made.
two studies which were deemed newsworthy (and i've been told distortion-
worthy) were the alleged african "eve" hypothesis (some years ago) and
the 5 native american "eves" (this summer) if you know of any "real"
references for these two cases, i'd appreciate if you could forward them
to me. i don't normally read this list so could you email to
baltuch@binah.cc.brandeis.edu
thanks
jacob
ps: is "the search for eve" the name of a book? if so could you throw in
a fuller reference to it? thanks