When you watch Penn senior Katherine Morucci and her mentor Katherine Moore examine pig skulls, you might guess they were analyzing the most precious of artifacts. They handle the remains with a loving care typically relegated to the irreplaceable and incredibly rare.

That’s probably because it’s precisely how this pair—the student, a double major in biology and the biological basis of behavior, and the professor, the Mainwaring Teaching Specialist at the Center for the Analysis of Archaeological Materials (CAAM)—sees these bones and was taught to hold such objects.

For the past year, they’ve teamed up to study the evolution of pig domestication using 35 teeth originating from the Hotu and Belt Caves in Iran and a site called Anau Depe in Turkmenistan. Aside from the few that Moore recently excavated, the artifacts have all been part of the million-piece Penn Museum collection since the 1960s. After months of work, the researchers have some idea of what story the teeth tell, which differs from their original theory.

“We were hoping to find two subgroups,” says Morucci, a Philadelphia native, referring to wild versus domesticated pigs. “We ended up finding three.”

To better understand how Morucci and Moore got here requires taking a step back. Moore studies faunal remains; Morucci works with live animals, like the pigs she spent her junior year researching at Penn Vet’s New Bolton Center. Their paths may never have crossed, but then Morucci enrolled in Moore’s “Archaeology of Animals” course in CAAM, the year-old initiative run by the Museum and the School of Arts & Sciences.

“When she told me she knew more about pigs than I did, all kinds of [doors] opened up,” Moore says. “I had a sample here of ancient pigs from a very important site in Iran that I knew had a lot of research potential, but I didn’t have the time and I knew I didn’t have the expertise.”

Interactions in the zooarchaeology course spurred Moore to bring her student into the field—to Peru, nonetheless—to teach her to analyze faunal remains. This eventually led to their current effort, which will culminate in Morucci’s senior thesis, focusing on when, where, and why people started domesticating pigs.

It’s a lofty project for an undergraduate. “She’s looking at 5,000 years of evolution. That’s quite cool,” says Marie-Claude Boileau, CAAM’s lab coordinator and the Center’s ceramics expert. “She’s using an older collection … answering that big question of domestication, what happens morphologically to the animal and how the behavior of the humans using the animals changed.”

The research itself requires patience and repetition. In four types of teeth, including second and third molars, Moore and Morucci looked at tissue and analyzed curvature to discern differences, what’s scientifically called geometric morphometrics. The samples included individual teeth as well as full mandibles, the latter of which required Boileau’s assistance to get useable X-ray images.

It’s known that as animal domestication evolved, humans started selecting for certain qualities, such as less aggression. It’s also been shown that domesticated animals have smaller brains than their wild counterparts—what’s called reduced encephalization—and in some cases experience neoteny, meaning some features don’t fully develop. Moore and Morucci sought these factors in the pig teeth.

“If our sample had both domesticated and wild pigs, we’d see both elongated and shorter, crunched up features of the teeth,” Morucci explains.

Though they did view differences, they found statistical significance for more than two groups. In other words, there was no clean breakdown between wild and domesticated swine. To boot, that statistical significance could have shown up because their material originated from three sites and different time periods.

“My results completely rejected our hypothesis,” says Morucci, who plans to apply to combined Ph.D./Veterinary Medicine programs after taking a year off after graduation. She’s still fascinated by what they learned, though. “It’s powerful that we’re picking up on some variance,” she adds. “We’ve uncovered a lot in this project.”

That’s a sentiment Moore shares. “The process of domestication is a little bit stop-start,” she says. “And the use of domesticated animals isn’t all or nothing. If you have a chance to hunt some big old male and he just tromps across your environment, you’re going to take it and you’ll add those remains to the remains of domestic pigs you are already keeping. We’re able to track a little more of that diversity.”

One challenge—aside from the tens of hours spent staring at and digitally processing magnified teeth images—is the small sample size. Given the origins of the teeth they have, that’s unlikely to change, but even this limitation doesn’t damper the duo’s enthusiasm over the pig teeth and the work itself. Their bond won’t likely end when the research does.

“She’s an unusual young woman in terms of her initiative and her enthusiasm and her warm charm,” Moore says of Morucci. “The people who can make these projects work are really exceptional.”

Morucci certainly has, and because of her dedication, hard work, and a little bit of good timing, science is one step closer to understanding the complicated relationship between people and pigs.