If you want to bore yourself, you can read it here: http://c.mfcreative.com/offer/us/obama_bunch/PDF/press_release_final.pdf
However, the bottom line is that they looked at the y-chromosome of a family of African-Americans named Bunch. Because Leona McCurry, Madelyn’s mother, had an ancestor named Bunch, and some oral history whispered about ancestry she was ashamed of, somebody made the incredible leap that she must be related to this family of African-Americans.
But since Barry does NOT have, could NOT have, this y-chromosome (nor did his mother, nor did SAD, of course, being females) and since there’s no mtDNA analysis that proves he’s descended from Leona McCurry or Madelyn or SAD, it’s proof of NOTHING.
I read it, thanks for the link, suitably unimpressed I must say, it’s like wish-fulfillment not genealogy, and I’m the lost Princess Anastasia.