Hey All, The following was posted to the Washington County list back in August. An article carried by AP was printed in our local paper on the day before Christmas. I am typing in an excerpt. "A type of DNA long thought to be inherited only from mothers may be influenced by dad afterall, a new analysis indicates. If proven true, scientists may have to rethink some basic beliefs about the timing of human evolution. Estimates of when humans migrated into Asia and Europe and even the age of 'Eve', the earliest common female ancestor, are based on the changes in mitochondrial DNA, which was assumed to come only from mothers. But a report in today's edition of the journal Science casts doubt on this assumption. 'Many inferences about the pattern and tempo of human evolution and (mitochondrial DNA) evolution have been based on the assumption of clonal inheritance. These inferences will now have to be reconsidered,' conclude the researchers led by Philip Awadalla of the University of Edinburgh, Scotland. DNA is the large molecule in each cell that contains the genetic instructions for its development. DNA in the cell nucleus combines material from both mother and father, providing the offspring with traits from both parents. However, there is also DNA in the mitochondria, the energy-producing portions of the cell, and that had been thought to come from mother alone. Knowing the rate at which DNA tends to change, anthropologists have used this DNA to calculate when human populations separated and estimate how long ago there was a single original human 'mother,' whom they call Eve. If it turns out that DNA from mothers and fathers are combining in mitochondria, those dates will have to be recalculated." From: <[email protected]> To: <[email protected]> Sent: Monday, August 30, 1999 6:59 PM Subject: [ILWASHIN] myDNA and genealogy > Here is an excerpt from a longer piece. The distaff lines are sometimes so > difficult to trace in many cultures, (including Washington County, Illinois > :-) I just thought many of you would be interested. I did not transmit the > longer piece, but can to anyone who wants it. This will, however, give you > the gist of the thing. Wish I could get to that conference you are all > talking about. heigh-ho, heigh-ho, it's back to school I go. Jerry in Boise > > "Mitochondrial or "myDNA" lasts much longer, possibly because there is > more of it. In some cases myDNA can actually be identified centuries > after the death of the individual. The other significant difference > between the two, and the one of primary interest to genealogists, is > that nuclear DNA changes from one generation to the next, but > mitochondrial DNA can be passed down unchanged on the maternal side of > families for as many as 39 generations. Every woman reading this article > has the same mitochondrial DNA as her mother, her maternal grandmother, > and so on back for an undetermined number of generations. Every man > reading this article has the same mitochondrial DNA as his mother, but > it will not be passed to his daughters; instead, his wife's > mitochondrial DNA will go down in his daughter's lines, and in the lines > of their daughter's daughters. > > Take your pedigree chart and follow your mother's line back as far on > the female lines as you can go. The woman at the end of the chart has > the same mitochondrial DNA as you do. If you are a man, the line stops > with you unless you have sisters to carry it on. If you are a woman the > mitochondrial DNA of your female ancestors will pass down to your > daughters. > > Using DNA from a tooth, Oxford University scientists recently > established a blood tie between a 9,000 year old skeleton know as > "Chedder Man" and an English school teacher who lives just a half mile > from the cave where the bones were found in 1903. It is the longest > human lineage ever traced. As described above, mitochondrial DNA comes > through the maternal line, so the teacher, Adam Targett, is not a direct > descendant of Cheddar Man. He would be related through Cheddar Man's > mother or sister." > > excerpted from an article by Mrs. Alden Davis