Again, I claim to be nothing but a rank amateur in following these things. And I'm not entirely sure what the point of confusion is here...
Let's start by throwing out the entire Biblical language the media used to spin the original story. The term "Eve" was in the post because it was in the story. It was in the story because it's the sort of hype that gets the cover of magazines. The mitochondrial DNA is NOT the result of the DNA involved in the genetic mingling of the sperm and the egg...the X and Y chromosomes in the nucleus. Mitochondrial DNA is OUTSIDE the nucleus and helps to fuel the cell. What you have of it is what the original egg had. So it only comes from yo mamma. Think of it this way: my mother had only boys. We have her mitochondrial DNA. We do not contribute eggs to the next generation, so that line comes to an end. So, there WERE many female contemporaries "Eve." They had kids. We are also their descendants. We just don't have their mitochondrial DNA, because--at some point--those lines came to an end. But here's where it gets interesting and perhaps is the source of the confusion here. We've been talking about the mitochondrial DNA from the same woman back at a certain point in time...AND we are talking about tracing different mitochondrial DNA after her. DNA of any sort doesn't reproduce itself exactly. It changes over time, and at a roughly predictable rates. Most mutations don't really affect anything and they never affect anything if they're in the mitochondrial DNA anyway...it just isn't used to pass on information for reproduction. So, if you can use those mutations to trace relationships among human populations and make some fascinating extrapolations about human migration in prehistory, etc. For example, they make a distinction between the population that left Africa on that last pulse and those that remained. The group that remains will have the widest variety of these mutations, while the one that migrates to another place will have a smaller variety of them. So they all start with mitochondrial DNA but then branch out into greater varieties of them. All the branches are identifiably of the original, but represent subsets with new mutations as well. These things DO have remarkable implications for evolution and human prehistory, though not those that Shane fears. We are now able to say incredible things with a remarkable level of certainty about what groups of people were doing in prehistory. ML ________________________________________________ YOU MUST clip all extraneous text when replying to a message. Send list submissions to: Marxism@lists.econ.utah.edu Set your options at: http://lists.econ.utah.edu/mailman/options/marxism/archive%40mail-archive.com
