Posted on 09/01/2007 9:01:21 AM PDT by Renfield
Prehistoric quid (wads of crumpled, masticated, shredded leaves) from dry caves in the American Southwest. Photo by Steven LeBlanc
In a groundbreaking study, two Harvard scientists have for the first time extracted human DNA from ancient artifacts. The work potentially opens up a new universe of sources for ancient genetic material, which is used to map human migrations in prehistoric times.
Before this, archaeologists could only get ancient DNA from relics of the human body itself, including prehistoric teeth, bones, fossilized feces, or — rarely — preserved flesh. Such sources of DNA are hard to find, poorly preserved, or unavailable because of cultural and legal barriers.
By contrast, the genetic material used in the Harvard study came from two types of artifacts — 800 to 2,400 years old — that are found by the hundreds at archaeological sites in the American Southwest.
“Quids” — small fibrous bundles of stripped yucca leaves — are the spit-out remnants of a kind of ancient chewing gum. Cells from long-dried saliva yield usable DNA. And “aprons” were thong-like woven garments worn by women. They are stained with traces of apparent menstrual blood, a source of DNA.
The Harvard study, featured in the summer 2007 issue of the Journal of Field Archaeology, “opens up the possibility of utilizing a much larger variety of human-handled artifacts” for DNA evidence, said project co-director Steven LeBlanc, director of collections at Harvard’s Peabody Museum of Archaeology and Ethnology.
Among the likely future sources of ancient DNA, he said, are “sandals, textiles, and cane cigarettes,” a reedlike smoke favored by early humans. LeBlanc’s co-director in the project was Thomas Benjamin, a professor of pathology at Harvard Medical School.
LeBlanc and others sampled 48 quids from four Southwestern archaeological sites — some of them on Harvard museum shelves for nearly 100 years — and 18 aprons found in Canyon de Chelly, a National Park Service site in Arizona still occupied by the Navajo Nation.
Aprons, and especially quids, are very common in archaeological collections, and are recovered from rock shelters or caves in the Southwest, Utah, Texas, California, and central Mexico. The DNA is preserved by the extreme dryness of such sites.
The Harvard study brings other good news for historians of ancient times. LeBlanc said the DNA captured from quids and aprons shows — in a preliminary way — that early farming populations in the Southwest descended from farmers in what is now central Mexico. That helps answer an old question among those who study the ancient Southwest: Was the idea of farming imported, or was it adopted by indigenous populations?
More broadly, archaeologists interested in migration patterns anywhere now have a new source for the DNA that can be used to track the movement of ancient people — though LeBlanc cautioned that the methods have to be retested and refined.
The origins of the earliest North American farmers are still officially a puzzle, and center on a now-lost tribe known as the Western Basketmakers. More than 2,000 years ago, these indigenous Americans started growing corn in what is now southeastern Utah and northern Arizona.
In what is now a boon to archaeologists who look at DNA, early farmers rested in the shade of rock formations, and spit out quids of chewed yucca leaves.
“The team was as surprised as everyone else that we could learn something about a possible migration over 2,000 years ago from ancient spit,” said LeBlanc. “Every artifact that we recover from such ancient sites now needs to be thought of in a new light, and handled in new ways, to ensure we preserve this DNA for future studies.”
To make sure the DNA was from ancient farmers and not from modern handlers, samples were taken from the cores of the quids and not from their surfaces.
Peabody Museum experts say future studies of ancient DNA from quids, aprons, and other appropriate artifacts are needed to test and refine Harvard’s preliminary findings.
The study was a collaborative project. Harvard researchers worked with genetic anthropologist Shawn W. Carlyle at the University of Utah; pathologist Lori S. Cobb Kreisman at Case Western Reserve University School of Medicine; curator Anna N. Dhody at the Mütter Museum at the College of Physicians of Philadelphia; anthropologist Brian M. Kemp at Vanderbilt University; and Francis E. Smiley, an anthropologist at Northern Arizona University. Ancient DNA expert David Glenn Smith offered his advice and the use of his laboratory at the University of California, Davis.
Some of the artifacts used in the DNA analysis were from collections at the Brooklyn Museum of Art, the Southwest Museum, and Northern Arizona University.
GGG ping.
Standing about 11 inches tall, a carving known as the "Lion Man" is the oldest known depiction of a human with animal features. It is one of dozens of finely crafted Paleolithic figurines discovered in the caves of southern Germany. (Courtesy Ulmer Museum, Ulm, Germany, photograph Kenneth Garrett)
article at: http://www.archaeology.org/0709/abstracts/iceage.html
The search for the origins of civilization has taken archaeologists to less pleasant places than Swabia. Nestled between France, Switzerland, and Bavaria, the German region is the heart of Baden-Wuerttemburg, a state that markets itself as a center for creativity and innovation. It's no idle boast. Hundreds of small high-tech firms dot the region. Giants such as Mercedes-Benz, Porsche, and Zeiss are all based in the gleaming, modern state capital, Stuttgart.
Archaeologist Joachim Hahn discovered this flute, above, carved from swan bone in the Paleolithic layers of Geißenklösterle. (University of Tübingen
American archaeologist Nicholas Conard is convinced Swabia's tradition of innovation goes back a long way: 40,000 years, give or take a few thousand. Excavating in caves east of Tübingen, a medieval town 20 miles south of Stuttgart, Conard has unearthed expertly carved figurines and the oldest musical instruments in the world. The finds are among the earliest art ever discovered, and they're extremely sophisticated in terms of craftsmanship, suggesting a surprising degree of cultural complexity.
Conard claims his finds are evidence of an intense flowering of art and culture that began in southwestern Germany more than 35,000 years ago. Although older art and decorations have been found--including geometric patterns on stones and personal ornaments in South Africa, as well as drilled shell beads on the shores of the Mediterranean--the figurines and instruments in Conard's caves are symbolic representations that reflect a state of mind with which modern humans can easily identify. "Figurative art began in Swabia, music began in Swabia," he says. "It couldn't have developed elsewhere, because the dates are just later elsewhere."
If he's right, it could change the way we look at the development of humanity. But Conard's conclusions have been controversial from the start, and he's still fighting an uphill battle to convince colleagues that the evidence backs him up.
OMG, please tell me the GEICO cavemen will not eventually turn into life imitating art.
Cool!
Excellent news. I wonder what DNA types have been found?
18,000 Year Ago
They had to have retreated to these refuges 23-18,000 years ago during the Last Glacial Maximum.
12,000 Years Ago
I wonder too. I found the abstract, but little additional information there.
Abstract
Steven A. LeBlanc, Lori S. Cobb Kreisman, Brian M. Kemp, Francis E. Smiley, Anna N. Dhody, and Thomas Benjamin
Quids and Aprons: Ancient DNA from Artifacts from the American Southwest
Journal of Field Archaeology 32 (2007) 161--175
The success of ancient DNA (aDNA) studies rests on the preservation of DNA through time, and can be limited by the availability of skeletal samples from particular times and locations. To help overcome this limitation, we sought to extract, amplify, and type human mitochondrial DNA (mtDNA) preserved within 1000- to 2000+-year-old artifacts from the American Southwest. In this study, we successfully typed mtDNA from 21 quids and aprons from Basketmaker II and Mimbres contexts. Recovery and analysis of human DNA from such artifacts will be helpful in confirming and extending genetic characterization of ancient populations for which human remains are scarce or unavailable. To illustrate the potential of these techniques, we tested them as a preliminary and independent line of evidence, relevant to the hypothesis that Western Basketmaker populations in the U. S. Southwest were descendants of migrant farmers from central Mexico.
That’ll make a fine separate topic. :’)
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Some of these guys seem to be reluctant to reveal their DNA data.
You archaeologists, always digging in the garbage.
Dirt is my life?
I read somewhere that Pueblo were descendants of the Anasazi who lived in Canyon de Chelly.
Can DNA be used to trace families back through Pueblo/Anasazi/Central Mexico?
(I was told no by a family ancestry DNA lab.)
Here is an abstract that might help answer this:
Native American mtDNA prehistory in the American Southwest
Ripan S. Malhi, Holly M. Mortensen, Jason A. Eshleman, Brian M. Kemp, Joseph G. Lorenz, Frederika A. Kaestle, John R. Johnson, Clara Gorodezky, David Glenn Smith
This study examines the mtDNA diversity of the proposed descendants of the multiethnic Hohokam and Anasazi cultural traditions, as well as Uto-Aztecan and Southern-Athapaskan groups, to investigate hypothesized migrations associated with the Southwest region. The mtDNA haplogroups of 117 Native Americans from southwestern North America were determined. The hypervariable segment I (HVSI) portion of the control region of 53 of these individuals was sequenced, and the within-haplogroup diversity of 18 Native American populations from North, Central, and South America was analyzed. Within North America, populations in the West contain higher amounts of diversity than in other regions, probably due to a population expansion and high levels of gene flow among subpopulations in this region throughout prehistory. The distribution of haplogroups in the Southwest is structured more by archaeological tradition than by language. Yumans and Pimans exhibit substantially greater genetic diversity than the Jemez and Zuni, probably due to admixture and genetic isolation, respectively. We find no evidence of a movement of mtDNA lineages northward into the Southwest from Central Mexico, which, in combination with evidence from nuclear markers, suggests that the spread of Uto-Aztecan was facilitated by predominantly male migration. Southern Athapaskans probably experienced a bottleneck followed by extensive admixture during the migration to their current homeland in the Southwest. Am J Phys Anthropol 120:108-124, 2003.
I am so thoroughly unknowlegable in technical science, I doubt I can even ask a valid question.
But, I’m gonna try anyway. How can there be any confidence that the DNA found on the chewed cud is from the cud chewer? The caves have been in existence since the cud was chewed, so it seems safe to assume that others have been in and out of the caves over the many centuries. How do they separate DNA unique to the chewer from all the possible/potential/probable contamination?
I do realize that in such issues, there’s a different level of pristine than what would be required for legal or criminal trial purposes.
I’m not trying to refute or poopoo the development, just trying to get up to speed in the how’s and whatfors.
PS. I’m pretty sure I wont be able to understand any answers but... maybe I can gleen enough hints on where to start reading up.
I can’t think of a way that human DNA would get into a cud, other than by chewing. If you were to pick one up, and rub it on your skin, some skin cells would slough off, and adhere to the surface, but the probably would not permeate the interior.
While the important news is the DNA recovery, I’m more than a little curious about the chaw and its purpose.
1. Was it, in the words of a modern company, a “mild sweet chew.”
2. Purpose: Was it dietary (Man, I’m starving. Here, chew some cactus.)
3. Purpose: I know that yucca cactus has been made into soap and candles. Were they brushing their teeth or simply extracting material for candles?
They might have been chewing it to get the fiber. Yucca fiber is very strong, and the Indians wove it into cord and rope.
The leaves are tough, coarse, and waxy...I can’t imagine that anyone would want to chew it for food or pleasure.
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