Professor Gates should research the history of the irish slaves he was descended from. I wonder if he knows anything about the fact that irish women were captured in ireland and shipped to the US and the West Indies as slaves and were often used for the purpose of being bred by african slaves in order to create a lighter skinned slave. They were also considered more valuable monetarily than the irish slaves. The children were always considered descendants of their fathers, thus legally african slaves, even though their mothers were white. Many blacks even today inist that a child with any amount of black blood at all is black. In other words, they are giving creditability to the plantation owners.
I wonder if he knows that his irish ancestors were sold for 5 pence, while his more "valuable" african forebearers were sold for 50 pence. This created a world were it was ok to beat an irish slave to death, but not smart financially to do so to an african slave.
I wonder if he has ever come across universty courses similar to this one: http://www.nde.state.ne.us/SS/irish/unit_2.html.