How Studying DNA from Ancient Animals Helps Humans
Robert C Cowen Columnist, The Christian Science Monitor
While on the campaign trail this fall, Senator John McCain would laugh at government-funded research on the DNA of bears. What would he think of the research on DNA from extinct cave bears that now has elucidated the bear family tree? It's the latest example of how scientists are using the increasingly sharp cutting-edge of DNA research to clarify the divergence of animal species, including humans.
New techniques to rapidly analyze DNA accelerate such studies. An increasing ability to garner useful data from tiny samples of DNA enable scientists to make the most of what little DNA they extract from such ancient remains as cave-bear bones.
Scientists now are beginning to glimpse the branching of Neanderthals and humans from a common ancestor some 700,000 years ago. They are studying 50,000- to 70,000-year-old DNA from such mammals as horses, wolves, and bison.
Such research is in its early stage. But a brief overview of its potential, published in the journal Science in July, concluded that it has "profound implications for exploring the biology of ancient organisms."
The cave-bear studies are a down payment on that promise.
Last July, Michael Hofreiter at Germany's Max Planck Institute for Evolutionary Anthropology in Leipzig and his team reported DNA analyses from a 44,000-year-old cave-bear femur and a 22,000-year- old bone of an extinct American short-faced bear. Most DNA is in the nucleus of cells. But some also is in bodies called mitochondria. It was this mitochondrial DNA (mtDNA) that the Hofreiter team described in the journal BCM Evolutionary Biology.
Then, two weeks ago, the Proceedings of the National Academy of Sciences carried a description of mtDNA recovered by a team led by Jean-Marc Elalouf at the Saclay Center of France's Atomic Energy ComA-mission. …