Is DNA testing that traces African tribe heritage for African-Americans accurate

Question:

Is DNA testing that traces African tribe heritage for African-Americans accurate and credible?

1. African-Americans are mixture of the numerous African peoples. How can we be sure?

2. Can this truly be traced through male DNA

Actor Isaiah Washington said his ancestors are Sierra Leone and Angola assuming he got testing on his mother and father side.

Other black celebrities mentioned Ghana, Nigeria, and various other places.

Can it really be traced accurately?

Best Answer - Chosen by Asker: It is both scientifically accurate and more than credible. For more info http://www.dnaancestryproject.com/...