Bridget Alex

Bridget Alex likes humans. And as it happens, some fifty thousand years ago, there were several kinds of them around

According to Alex, a graduate student in anthropology and human evolutionary biology, for several thousand years of our history, we (that is, modern humans) had something else to worry about besides glyptodons and mammoths: our one-time neighbors, the Neanderthals.

The reunion between modern humans and the Neanderthals was brief, however, and probably not particularly sweet. Around 40,000 years ago, the Neanderthals went extinct, leaving scientists to wonder why we survived and they didn’t. Summing up the question, Alex asks, “What’s so special about us? Were we smarter than them, stronger, or was it just luck?”When our common ancestor in Africa split around 400,000 years ago, some left to become the group we now think of as the Neanderthals and others remained and evolved into modern humans. By the time the two groups reunited some 50,000 years ago, they were genetically and physically distinct, though not enough to be technically considered different species. “Speciation is a process, not a moment,” Alex explains.

Work to be done

As Alex tells it, when she first came to Harvard she couldn’t imagine making a contribution to such a difficult question. “I thought it was almost too big and exciting for a beginning graduate student like me to tackle,” she admits.

However, due to ever-evolving scientific techniques for measuring everything from microscopic plant remains to radiocarbon concentrations, and the relatively primitive scientific tools available to the first waves of scientists who studied the Neanderthal/modern human connection in the nineteenth century, many of the dates associated with the Neanderthal fossil record have proven unreliable. “Radiocarbon dating tools were not yet available and many samples were likely contaminated, so there’s still a lot of work to be done,” Alex says. “Now, we can measure smaller specimens, are better at removing contamination, and are more thoughtful when it comes to choosing meaningful items to test.”

Alex’s current project focuses on a “brief” window of about 5,000 years approximately 39,000 years ago, when modern humans and Neanderthals coexisted in what is today known as the Balkans. “Something happened to decimate their numbers,” Alex says, “and when they repopulated, there were many more modern humans than Neanderthals.” Alex’s recent findings, which document this sudden decrease in the Neanderthal and modern human populations, coincide with a major geologic event: the Campanian Ignimbrite, or CI, eruption, in Southern Italy.

While there are many theories of why modern humans won out over the Neanderthals, so far Alex’s personal bet is on projectile weapons. “Before projectiles came along, they had to fight each other and hunt prey at close range.” From that perspective, modern humans’ innovation would have given them a clear leg-up. “Projectile weapons would have been a huge advantage over Neanderthals: modern humans could outcompete and kill them,” Alex explains. That said, “It’s difficult to demonstrate that particular stone tools could or could not have been used as projectiles. It’s a great idea, but it still needs to be tested more.”

A long and winding road

Alex’s research takes her to places like Serbia, Poland, and Israel in pursuit of evidence from this pivotal juncture in the history of human evolution. But while she may be single minded now, Alex confesses that she wasn’t as certain of her path as an undergraduate. Although in hindsight her winding path to human evolutionary biology has a certain logic to it, taking her through chemistry, earth sciences, anthropology and back again, she insists she had no idea where her interests would eventually take her. “I kept studying what attracted me. It looked like I had a lot of foresight but I didn’t at all,” she says, laughing.

Much like fieldwork, the decisive moment in Alex’s academic career happened outside of the classroom, in an Internet café in Barcelona during her junior semester abroad. As Alex tells it, she was reading a New York Times article that described how scientists used nuclear reactors to determine the composition of ancient pottery and ascertain based on clay composition whether the pottery had been traded or not. This intersection of anthropology and hard sciences excited Alex greatly. “I saw that and said, ‘wow, that’s what I should do!’” With the support of her anthropology advisor at Dartmouth, Professor Deborah Nichols, Alex undertook a senior thesis to analyze the elemental composition of Early Formative pottery from the Teotihuacan Valley in Mexico.

Helping others find their way

The important role that mentorship played for Alex as an undergraduate trying to find her way drove her to find opportunities to mentor younger students. “I like people at the stage when they’re trying to decide what to do with their lives, probably because it was such a hard decision for me,” she says.

That’s why she jumped at the chance to apply for a resident tutor position in one of Harvard’s undergraduate houses. “As soon as I knew what it was, I knew I would love it.” She credits Stephanie and Rakesh Khurana, Masters of Cabot House, with creating a welcoming environment that she, along with her fellow resident tutors and the undergraduates they advise, is happy to call home. “We have such a good community,” she says. “The Khuranas make it a home, a place the students want to come home to.”

After a hiatus during the 2013–2014 school year when she traveled to Israel as a Fulbright Scholar, Alex is now serving her second year as a resident tutor. The role brings much-needed balance to her life as a graduate student. “I can only do my research for so many hours a day before I need to talk to people,” Alex says with a laugh. It also gives her a different perspective on the undergraduates she teaches. “I’m always impressed by the caliber of discussion that goes on in the dining halls,” she says, while in the classroom it’s sometimes hard to gauge how much they’re learning.

That said, it’s hard for us modern-day humans to live up to the accomplishments of our forerunners 40,000 years ago. “Through my mentoring I’m often impressed by Harvard undergraduates,” Alex says, “but more often I’m impressed by the accomplishments of humans 40,000 years ago. I doubt many Harvard students could take down a mammoth in Ice Age Europe or make such exquisite cave paintings.”

Story credit: Lusia Zaitseva