How Drones And DNA Can Drill Down To The Past

Jun 28, 2021

Earlham College researchers have returned to Iceland with a variety of tech tools to help Icelanders learn more about their Nordic past.

Computer scientist Charlie Peck and biologist Emmett Smith have spent a month at the end of a long peninsula on the east coast of Iceland. Peck explains if you were to drop a stick in the ocean in Norway, the currents would likely bring that stick near the sites where they are working with Icelandic archaeologists.

Peck and Smith are doing what they call 21st century science. Examining the past not only requires archaeologists, but computer scientists using drones to locate where to dig and biologists to identify DNA found in the environment, particularly soil.

The National Geographic Society is funding the project looking at some of the earliest Viking settlements in Iceland in the year 875.

Peck, Smith and the archaeologists want to know what was there and what the people were doing there.

According to Smith, "If I take a soil sample, extract DNA, are we going to find things like particular whole species or fish species that we know they would be consuming? Are we going to see sheep we know they were husbanding? Do we have dogs, horses and cattle which are not in Iceland natively?"

Peck pulls up a picture during our Zoom interview that shows very dark soil. That's the fire pit his drone, guided by computer software, picked up in a giant field.

"You'll fly and pick out features through the change in surface plants that tells you to dig here," he says.

This image is assembled from hundreds of individual ones taken from a drone.
Credit Earlham College

They are also creating a 3D map in a river valley to measure erosion. Climate change is more pronounced in Iceland than in the Midwest and the scientists, when comparing their map to a British-made one in 1942, can determine how nature moves in as the glacier recedes. Microbes in the soil are also useful in determining this.

Smith has dozens of soil samples but moving them across international borders isn't easy. They will use a series of techniques and specialized tools to extract the DNA from the soil samples and store it in tubes. "Then we just come back with a hundred 1.5 ml tubes on frozen vegetables - to keep them cold - and bring those back to Indiana to do the sequencing and the analysis on."

What Have They Found?

Archaeologists discovered a Roman coin which could mean the site was once a trading post.

Smith focuses on the DNA found in soil.

"The henbane and the cranberry in particular indicate that we are seeing ancient DNA that was brought to this location in the form of plant material by the settlers. We've not yet found any human DNA. That was our goal. But every year the technology (and) the analysis tools get better."

Yujeong Lee is telling Earlham's story on the Earlham Field Science Instagram account.

Blog: https://fieldscience.cs.earlham.edu/ and https://fieldscience.cs.earlham.edu/index.php/blog-2021/