Mitochondrial DNA

In these dark days, in which some would have some inane concept of an Intelligent Designer taught alongside the theory of evolution, it's interesting to see what genetics may accomplish. For one, it shows that we are all Africans, an unpleasant revelation to some, and that what we call our 'roots' may be in a completely other place than we thought.
Our friend in drawing these conclusions is a piece of genetic material called "mitochondrial DNA". Ordinary DNA does the genes' evolutionary job by mutating with each new generation. In contrast, mtDNA (as mitochondrial DNA is called for short) propagates through the maternal line, and never changes. This means that your mom, her mom, and any mom before that all have the same mtDNA as you. So does all the offspring of any of your maternal ancestors. This means that if you can find someone with the same mtDNA as you, the both of you must have had an ancestor in common at some time.
A television show illustrated the strange types of revelations this can produce. By assembling a database of mtDNA from all over the world, ordinary people were stupefied to learn that their ancestors came from Mongolia, France or Central Africa. I watched a black man in England, heading off to the lab to get his results, be dumbstruck when he learned that he did not stem from the royal family of Ghana (which he'd secretly confessed to hoping), but instead from a rural village in Bavaria, Germany.
That's the other surprise: skin color means close to nothing when it comes to tracing your heritage. For example, the continent of Africa, our common home, still hosts virtually all of the world's genetic variety. Meaning that if all the world except Africa were destroyed, present-day Africans could repopulate the planet, producing the same kind of racial diversity seen today.
I'm seriously considering submitting a DNA sample to see where in the world I have cousins or ancestors.