Is it true that all humans had a common ancestor?

Every person alive today can trace their DNA lineage to a single man and woman. This is not the Adam and Eve of the Judeo-Christian religion, but two individuals who lived in ancient Africa hundreds of thousands of years ago. These two did not actually live at the same time. How can this be? Well, the men and women of the original small human population of Africa who lived around 200,000 years ago passed on their genes just like everybody else does. But not all of those separate lineages survived. Some of the original people either didn't have children due to injury, disease, or death, or someone in their lineage down the line didn't have children due to those same reasons. Countless lineages have gone extinct just like different animals species. The Mitochondrial DNA (that passed from a mother to her children) of one woman, known in science as "Mitochondrial Eve," was lucky enough to survive the platitudes of prehistoric life to be passed on to every human alive. The Y chromosome of one man, "Y Chromosomal Adam," born thousands of years later was also lucky enough to survive as well. For an explanatory chart and a much more eloquent description of the process, see the book Before the Dawn (2006) by Nicholas Wade.