Screaming Penguin - Source Does Matter

The "Genographic Project" is pretty ambitious and very interesting. It is a new project to map human origins using DNA. (Insert your own joke about "evolution" here, DNA being the major evidence for evolution and the means for natural selection to "work".)

The Genographic Project will collect DNA samples from over 100,000 people worldwide to help piece together a picture of how the Earth was colonised.

Using the Y chromosone and Mitochondrial DNA you can basically create a phylogenetic tree for each sex of a species (well in the case of humans and other animals you can, when there are no sexes and such things get more complicated, similar to the way we use "genealogy" to track human heritage and ancestry, but for each gene there are usually more paths and thus too much noise, unless you pick genes that are only passed on to one sex).

Members of the public will be able to buy a kit that contains all the material needed to add their genetic information to the database.

The project aims to answer a set of important questions about human origins. Science at present has a general but not detailed understanding, this project is an attempt to fill in the details.

More info DNA project to trace human steps

And National Geographic has a GREAT SITE about the entire project and resources to learn about genetics in general, great stuff - Genographic Project.