Archaeologists and those studying human remains from the Middle Ages and other periods may soon have a new method to examine bones, which will leave these remains undamaged.
In research published this week in the journal Scientific Reports, researchers from the University of Colorado Boulder describe a new method for screening bone samples to see if they contain collagen. Unlike existing tools that look for that type of tissue, the team’s approach won’t damage the bones in the process.
Collagen is a useful molecule than can reveal a wealth of information about human remains–from how long ago a person died to what he or she may have eaten. It is sometimes found in bones from centuries or even thousands of years ago. But this material, which helps to hold together human bones and other tissue, also doesn’t age well. Many skeletal remains, even those from well-preserved graves, don’t contain much of it.
Matt Sponheimer, a professor of anthropology at the University of Colorado Boulder, explains, “These remains have lain intact for thousands of years, so it always hurts a little bit to destroy a sample. It’s doubly tragic if you do it, and it’s all in vain. That’s what we’re trying to prevent.”
Several years ago, one of Sponheimer’s colleagues was tasked with extracting collagen from a series of ancient bone samples. “My student was spending weeks and, ultimately, months of lab time trying to get dietary info from ancient collagen, and it was working incredibly poorly,” Sponheimer said. “I thought to myself, ‘There has to be a better way.'”
As it turns out, there was. In their latest study, Sponheimer and his colleagues discovered that they could calibrate a machine called a near-infrared spectrometer to test bones for the presence of collagen.
The process is surprisingly easy according to the researchers. The instrument, which operates by way of a handheld probe, scans samples of bone and then–in a matter of seconds–churns out an estimate of how much collagen is inside.
“I’ll tease that the longest part of the process is typing in the file name,” added Christina Ryder, a graduate student and member of the research team.
To make sure that their method was accurate, the researchers tested their instrument on more than 50 samples of ground-up bone with known concentrations of collagen. The tests correctly predicted the approximate concentrations of collagen within each of those samples. It worked with 44 pieces of whole bone, too.
Ryder added that the entire spectrometer is about the size of a briefcase, which means that the team can carry it with them into the field.
It’s already gone through one high-profile dry run. Last year, Ryder flew to Germany to meet with colleagues at the Max Planck Institute for Evolutionary Anthropology. The researchers wanted to date human remains uncovered from Dolni Vestonice–a one-of-a-kind archaeological site in the Czech Republic that hosts some of the oldest known examples of representational art in human history.
“The grad student on this project had only six vials of samples from human burials,” Ryder said. “That was all she had, and that was all anyone was going to have for the foreseeable future.”
Thanks to her near-infrared spectrometer, however, the researchers were able to limit how much bone they had to destroy for their radiocarbon dating. The group published its results earlier this month in the Journal of Archaeological Science: Reports.
And, Sponheimer said, the team’s method may one day also allow them to screen bones for the presence of something even more valuable than collagen: ancient DNA.
“For those who do this work, the practical benefits are obvious,” Sponheimer said.
You can read their article “Saving Old Bones: a non-destructive method for bone collagen prescreening” from Scientific Reports.
Top Image: Ancient skeleton discovered in Pakistan – photo by mishra-ajay / Flickr