Sasha:
Did anyone see that show where they have traced the DNA of the whole world back to EVE???????
No, they haven't! At least not in any sense that gives support to the Genesis account. However, scientists did give the moniker "Eve" to a particular person whose existence is logically inevitable, namely, the most recent common ancestor of all living humans in a purely matrilineal line. Imagine everyone on earth goes to visit their mother, and then their mother's mother and so on. So you arrive at your mother's house along with your siblings, and then go to your maternal grandmother's house where you meet up with your first cousins and aunts and uncles, then on to your great-grandmother's house where things are starting to get crowded, as your great-aunts and first cousins once removed and second cousins and whatever descendants they have are also there. (Obviously normal rules of time and space and life and death don't quite apply in this thought experiment). So you move on, this happy throng, all descendants in a purely matrilineal line from this woman, your great-grandmother. As you go, you see other pilgrims visiting their respective matriarchs, all gathering in numbers and joining together as they go further backwards in time. You are initially surprised to notice that many women have no visitors at their homes but that is because either they never had children (or their line has completely died out) or they only had sons (or at least have nobody alive who is a daughter of a daughter.... of their daughter). You cross continents and travel back millennia, all mothers and daughters, joining up with ever more distant relatives. As the groups get larger and larger, you notice that fewer and fewer of the local women are receiving visitors. Some of them must be ancestors of people now living but just didn't have an unbroken chain of daughters. Eventually you will come to a time and a place where all the pilgrims are visiting one woman who will undoubtedly be surprised at the billions of people who've turned up unexpectedly. That woman, although she doesn't stand out from any of her contemporaries, is the person who scientists have called Mitochondrial Eve. Such a person must have existed (unless you posit that humans are not all related, which nobody seriously does). But our thought experiment doesn't tell us much about her other than that she had at least two daughters and it would obviously be impossible to do what I have described. Luckily though, there is a way we can find out more about her. Through an interesting quirk of biology, we get a section of our DNA (our mitochondria) only from our mothers. Unlike most DNA, this doesn't combine with the DNA of our fathers, so it never gets jumbled up. That means that your mitochondrial DNA should be exactly the same as that of your mother and grandmother and so on. If this were indeed the case though, everybody on earth would have the same mitochondrial DNA and it wouldn't tell us very much. However, we have luck on our side once again. Mitochondrial DNA like all other DNA sometimes replicates with less than 100% fidelity. As it is essentially junk DNA, these flaws or mutations happen randomly. So if we can work out how often these changes happen and get a large enough sample size, we can determine approximately where and when Mitochondrial Eve must have lived. After a considerable amount of cheek swabs and processing power, it turns out that this "Eve" lived sometime around 200,000 years ago, and almost certainly in Africa. So definitely not the biblical character Eve, then! Further, it's obvious both from our thought experiment and from other evidence, that she was not the only woman alive at the time, nor was she even the only ancestor of all humans alive at the time. It is only with hindsight that she gains the title of Mitochondrial Eve. It can be very difficult, especially for those brought up with conventional creation myths, to realise that there were never just two humans, but that we slowly and gradually evolved as a species, but it turns out that the true account of our ancestry can be endlessly fascinating and informative, far more awe-inspiring than primitive origin myths and with the sublime advantage of actually being true.
