One week ago I blogged about ancient gum. And now, thanks to Blaine Bettinger of the Genetic Genealogist, I’ve got some more gummy anthropology news for y’all to chew on… This time with a genetic twist.
In the Summer of 2007 issue of the Journal of Field Archaeology, Steven LeBlanc et al. write on recovering mitochondrial DNA from 2,000 year-old quids (a chewing plant, image to your right), as well as from aprons worn by Western Basketmakers. The Western Basketmakers were a group Native Americans that lived in caves and rock shelters in what is now southern Utah and northern Arizona. Here is the title of the paper, “Quids and Aprons: Ancient DNA from Artifacts from the American Southwest.”
According to ScienceNOW Daily News, LeBlanc had a eureka moment when he was looking at Harvard University’s Peabody Museum collection of quids, and he realized, “Quid … saliva … DNA … DING!”
“teamed up with Thomas Benjamin, a cancer biologist at Harvard Medical School in Boston, Massachusetts, and other researchers. They pulled mitochondrial DNA from 48 quids and from 18 aprons that had been stained with what was likely menstrual blood. Then they scanned the DNA for various molecular markers called haplogroups, which appear in different frequencies in different parts of the world.
LeBlanc and his colleagues found that about 14% of these samples contained haplogroup A. This haplogroup is extremely rare in the Southwest, but it occurs in about half of the population of Central America. The intermediate frequency in the sample of Western Basketmakers fits with the idea that they migrated from somewhere in central Mexico, bringing agriculture into the turf of foragers. The results were confirmed by a second laboratory, and LeBlanc says the absence of European haplogroups rules out the possibility of contamination.
The larger conclusion is that museum artifacts can provide a new source of data. Quids are common in collections, notes Connie Mulligan of the University of Florida, Gainesville, although aprons less so. Next, the team hopes to sample other textiles, samples, and cigarettes made from hollow reeds. “It’s a neat and novel application,” says Anne Stone, an ancient DNA expert at Arizona State University in Tempe. She notes that testing artifacts may be especially important when Native American tribes are reluctant to allow sampling of their ancestors’ skeletons.”
I’ve added emphasis to the biggest conclusion drawn from this mtDNA analysis, the statement that the Western Basketmakers were from down south.
NPR’s Joe Palca also covers this news in, “DNA from Spit Helps Decode Lives of Early Settlers.” Check out what he has written too.