john hawks weblog

paleoanthropology, genetics and evolution

Hobbit DNA hunt

Wed, 2011-01-05 19:30 -- John Hawks

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.

(via Dienekes)

Neandertals

For years, I've worked on their bones. Now I'm working on their genes. Read more about the science studying these ancient people.

Denisova

From a finger bone of an ancient human came the record of a completely unexpected population. My lab is working on the science of the Denisova genome.

Acceleration

The advent of agriculture caused natural selection to speed up greatly in humans. We're uncovering some of the ways that populations have rapidly changed during the last 10,000 years.

Malapa

Just outside Johannesburg, the Malapa site is producing some of the most exciting finds in human evolution. This site is the headquarters of the Malapa Soft Tissue Project.