Human Migration
The Mitochondrial Eve of 200,000 years ago (ME for short henceforth) is NOT our common ancestor, or even common genetic ancestor. She is the most-recent common ancestor of all humans alive on Earth today w.r.t. matrilineal descent.
Check the following links:
NGM National Geographic (2006) human journey (article By James Shreeve)
National Human Genome Research Institute
Anthropology Links
Oldest Human Fossils Identified
Oldest human fossils dated as 200,000yrs old
The first human being in Ethiopia
The Leakey Foundation