ASU geneticist tracks pathogens' evolution

Anthropological geneticist Anne Stone spends much of her time trying to decipher the origins and evolutionary paths of some of the world’s oldest diseases.

She has done extensive work in her Arizona State University Laboratory of Molecular Anthropology, investigating how primates, including humans, adapt to their environments, particularly in terms of dealing with pathogens.

Tuberculosis (TB) is her main focus, though she is currently involved in multiple research projects.

Recently, the American Association for the Advancement of Science shone its spotlight on Stone, who is a professor in the School of Human Evolution and Social Change in the College of Liberal Arts and Sciences.

Stone’s work has helped strengthen the case for a shift in paradigms regarding TB’s human-animal link. Previously, the prevailing theory was that cattle introduced the disease to humans, but research like Stone’s, which shows evidence of TB in the Americas before the introduction of cattle, points to the opposite.

Understanding how TB moved and morphed in the past can help us deal with modern strains of the re-emergent disease.

“It’s exciting, because the research we’re doing wouldn’t have been possible two years ago,” Stone says.

Stone’s research compares modern DNA samples of tuberculosis to tuberculosis DNA isolated from prehistoric people who show skeletal changes caused by the disease. In the past, extracting such DNA was problematic because ancient remains have decayed over millennia, and in the process, acquired fresh microbial and soil DNA.

Now, improved extraction techniques have changed that, allowing her to capture and sequence TB DNA much more quickly.

Stone’s recent lab findings, which have been submitted for publication, should help scientists better grasp pathogens’ evolution, as well as which pathogens are circulating in non-human primates.

Stone plans to continue this line of research by collecting, analyzing and hopefully linking strains of TB, as well as leprosy, that are not yet sequenced.