Every so often, a reader asks me if I know any new rumors about DNA sampling of “Homo floresiensis”. I’m not holding out much hope for success given the tropical location and past failure, but with new technology, who knows? In Nature News, Cheryl Jones tells us that the University of Adelaide’s Centre for Ancient DNA is set to try again: “Researchers to drill for hobbit history”.
I mentioned yesterday that dental cementum is packed with calcified epithelial cells, among other things (“Tartar control and Neandertal plant use”). The presence of this organic material in calculus has led to some recent success with ancient DNA recovery:
Most genetics research on ancient teeth has focused on the inner tooth tissue, dentine, but Adler's team found that cementum, the coating of the root, was a richer source of DNA.
Drilling is a technique commonly used to sample teeth and bone, because it minimizes damage to the precious specimen. But Adler's team found that the heat generated at standard drill speeds of more than 1,000 revolutions per minute (RPM) destroys DNA rapidly, causing yields to be up to 30 times lower than for samples pulverized in a mill. Reducing the drill speed to 100 RPM alleviated the problem.
I hope they have some luck, the results will surely be interesting no matter what they may be.
Jones is an author of The Bone Readers: Science and Politics in Human Origins Research.