The source that David cites pointing out that the sibling DNA by itself is not conclusive is correct in my estimation. The media is reporting that bin Laden’s sister died in the US and that her DNA was used in the test. This alone could give a statistical likelihood (probably ~90%) that the dead body was a sibling of the hospitalized sister. Another relative’s DNA sample could help confirm the identity. If another sibling was used, then they could be certain that it was a bin Laden sibling, but still not confirm that it was Osama. If, however, they also had DNA from one of bin Laden’s children, this (combined with the sister’s DNA) would be pretty definitive that the body was Osama’s since it would show with high probability that it was the sister’s sibling and the child’s father.
I’d also like to follow-up on David’s surprise that the government could be so efficient at getting this DNA evidence. The feds can certainly do things very quickly, but they simultaneously waste resources. The DNA labs that do paternity or sibling tests for a fee are operating to make a profit. They could in theory produce same-day or overnight results, but this would require some combination of higher wages, more employees and more expensive equipment. I expect that the profitable labs have found that there is not enough demand for very quick results to justify the high fees they would have to charge to keep this type of operation going. On the other hand, the feds have their own printing press and a subservient legislature, so they can overpay too many workers and buy the latest-and-greatest instrumentation, but use it only once, just to get a DNA test done if that’s what they want to do. They don’t have a profit motive, so they aren’t economically efficient, but they can waste resources faster than anyone!7:50 am on May 3, 2011 Email Kathryn Muratore