I was listing to NPR a few weeks back (can’t remember what program) - they were talking to some geneticist who had determined from studying mitochondrial (maternal) DNA samples across europe that all europeans came from one of 7 women. I wanted to search the web for some more information. Unfortunatley, I was in my car and didn’t remember to write anything down when I got out. Does anybody know where I can find more information on this project to satisfy my curiosity?
Despite the catchy phrase, there are not seven women involved, but seven matriarchal groups from which all Europeans are apparently descended. ABCNEWS.com had this item about it: http://abcnews.go.com/sections/science/DailyNews/daughters000420.html The web page also includes a link to Oxford Labs, which will test your DNA for $180 & tell you which of the seven lineages you belong to.
Sounds kind of fun, and the procedure couldn’t be simpler (the lab sends you a kit for swabbing the inside of your cheek, which you return & they analyze).
Do you mean stuff like this?
Wow, great sites! Jawbreaker, between these two (fillet and Jon F you have a library of information.
Mitochondria (singular mitochondrion) are tiny bodies found in every cell, upwards of tens of thousands of them in each cell. They may be descended from bacteria-like organisms that lived in sybiosis with our very primitive ancestors. Each of us gets mitochondria only from our mothers. Nuclear chromosomes from the sperm cross into the egg, but mtDNA does not.
From analysis of mtDNA of hundreds of people alive today, it appears that we all are descended from a single female who lived roughly 150,000 years ago (“Eve”). The date is uncertain. The best guess is that she lived in Africa, but this is even more uncertain. Some people have taken these results to mean that she was the only human female alive at that time, or one of only a few. That conclusion is not warranted by the facts.
Just by pure chance, you would expect one person’s mtDNA to become fixed at 100% of the population after many generations, regardless of how many other people were alive at the time. This is genetic drift, by which the frequency of a gene tends to approach either 100% or 0% in the absence of strong selection. Because mtDNA is passed from mother to child without recombination, the whole mitochondrial genome acts much like a single gene under genetic drift. Genetic drift is strongest when the population is small, but it can have a strong effect over a period of 100,000 years even when the population is not very small.
The Y-chromosome is also passed from father to son without recombination, so a similar analysis can be applied to it. It is not inconceivable that “Adam” lived in a different time frame from Eve. The time estimate is so imprecise, it would be hard to know for sure. The estimates overlap, but Adam may have lived longer ago than Eve. See more here
Also, note that there wasn’t only one “Eve”. Everyone is also decended from Eve’s mother, and her grandmother, and her father, and all of her ancestors.