Ryan R. Christ ’13 has always loved making models of how things work. When his mother gave him a library card at age eight, he went straight for “the molecule books” to make little drawings of how atoms turned into earthly matter and living things.

“I was all over this idea that you could model the universe and how it works,” he said.

He wanted to be a theoretical physicist until 10th grade—when he realized how much math that would take.

So in his first year at Harvard, Christ tried his hand at biology instead, studying Alzheimer’s disease in HMS professor Mel Feany’s lab at Brigham and Women’s Hospital.

Many scientists suspect that Alzheimer’s develops when brain cells lose their ability to traffic molecules within their interiors. Christ tested this idea in fruit flies, manipulating the cargo-moving proteins in their neurons and lighting them up with fluorescent dye to see how trafficking activities were associated with disease.

To do this, he inspected glowing fruit fly brains, one by one.

“Imagine trying to dissect out a fruit fly brain with forceps under the microscope,” he said. “If you had drunk coffee and your hands were shaky, forget it.”

The delicate labor paid off. Months in, Christ glimpsed a fruit fly brain under his microscope that stood out: a brain that had abnormally high amounts of a trafficking protein called Rab6, and fewer signs of  Alzheimer’s damage than in other flies.

“That was one of the most exquisite moments in lab,” Christ said. “Soon I was sitting with 20 'Nature' papers spread around me, drawing model after model furiously on my whiteboard to imagine how this protein might work.”

In sophomore year, Christ began imagining bigger models—curious not only to understand how Rab6 functions in the fruit fly, but how vast, interconnected systems of similar proteins might work together in humans.

This work is called “pathway analysis”—the science of modeling how genes work in systems, how they evolve and get passed in our DNA from generation to generation, and how they cause human disease when they go haywire.

It’s also a field that Christ learned would demand a lot of mathematics. This time he dove in, declaring an Applied Mathematics concentration and advanced standing to receive a Masters degree in Statistics.

“I realized I needed the math to build the kinds of models I wanted to build,” he said.

One of the first things that Christ and roommate Joshua Wortzel ’13 did when they became roommates in Lowell House their junior year was to buy a whiteboard for themselves.

“We took a maiden voyage to Home Depot and got this huge whiteboard—eight by four feet—and put it above Ryan’s bed,” Wortzel said. “Sometimes he pulls out the dry erase pens and goes crazy with his theories.”