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Banner image: A fragment of bone collected from Spain and dating back to about 30,000 to 50,000 years ago. (Credit: Sponheimer lab)

A team of CU Boulder anthropologists is out to change the way that scientists study old bones damage-free.

If that sounds like a macabre goal, consider this: Bits of well-preserved bones are valuable to researchers studying humans who lived thousands to hundreds of thousands of years ago.听

These samples sometimes contain collagen, a useful molecule than can reveal a wealth of information about human remains鈥攆rom how long ago a person died to what he or she may have eaten.

鈥淏one collagen is really a treasure within the realm of archaeology,鈥� said Christina Ryder, a graduate student in the Department of Anthropology at CU Boulder.

Now, she and her colleagues have come up with a creative way to be thrifty with that treasure.

In research , the group describes 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鈥檚 approach won鈥檛 damage the bones in the process.

For anthropologists, the test could be 鈥渁 game changer,鈥� said study coauthor Matt听Sponheimer, a professor of anthropology at CU Boulder.

鈥淭hese remains have lain intact for thousands of years, so it always hurts a little bit to destroy a sample,鈥� he said. 鈥淚t鈥檚 doubly tragic if you do it, and it鈥檚 all in vain. That鈥檚 what we鈥檙e trying to prevent.鈥�

A better way

It鈥檚 a goal that emerged out of many hours of frustration. Several years ago, one of Sponheimer鈥檚 colleagues was tasked with extracting collagen from a series of ancient bone samples. Collagen within bones is a bit like a birth certificate; if scientists can find enough of it, they can use collagen to determine the age of a human specimen through radiocarbon dating.

But this material, which helps to hold together human bones and other tissue, also doesn鈥檛 age well. Many skeletal remains, even those from well-preserved graves, don鈥檛 contain much of it.

鈥淢y student was spending weeks and, ultimately, months of lab time trying to get dietary info from ancient collagen, and it was working incredibly poorly,鈥� Sponheimer said. 鈥淚 thought to myself, 鈥楾here has to be a better way.鈥欌��

As it turns out, there was. In their latest study, Sponheimer, Ryder and their 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, Ryder said. The instrument, which operates by way of a handheld probe, scans samples of bone and then鈥攊n a matter of seconds鈥攃hurns out an estimate of how much collagen is inside.

鈥淚鈥檒l tease that the longest part of the process is typing in the file name,鈥� Ryder said.

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.听

Six vials

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鈥檚 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 Doln铆 V臎stonice鈥攁 one-of-a-kind archaeological site in the Czech Republic that hosts some of the oldest known examples of representational art in human history.

鈥淭he grad student on this project had only six vials of samples from human burials,鈥� Ryder said. 鈥淭hat was all she had, and that was all anyone was going to have for the foreseeable future.鈥�

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 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.

鈥淔or those who do this work, the practical benefits are obvious,鈥� Sponheimer said.

Coauthors on the new paper include Erin Smith, formerly a graduate student in anthropology at CU Boulder; Helen Fewlass and Sahra Talamo听of the Max Planck Institute for Evolutionary Anthropology; and William Pestle of the University of Miami.