Best laid plans / Of mice and their whiskers

The walls are clad in unyielding white tiles, the kind that gleam too brightly under fluorescent lights and make even whispers feel intrusive. This is the domain of the university’s evolutionary biology department—a place where the sterility of the space belies the lively, imaginative work happening within. As you venture deeper, the austerity begins to crack and the scene becomes more animated, with proud displays of scientific research, flyers for lectures, photos from conferences.

On the fourth floor’s northern wing, an office spills its enthusiasm for research into the corridor. Black mouse-shaped stickers and scrawled notes compete for space on overcrowded pinboards. In the center of it all is a massive, blown-up photograph of a mouse, its whiskered snout magnified to an almost comical scale—what’s normally a three-inch rodent now looms at human height. It’s a little chaotic, but undeniably charming, like a teenager’s wall devoted to a favorite band. And just as my mind drifts to visions of giant mice, a voice interrupts: “You’re looking for Jake?”

I first met Jake Gable in late 2016, during my freshman year, when he was part of the teaching team for a course called Understanding Darwinism. I remember his introduction vividly: he’s from Washington, loves peanut butter, and studies the whiskers of mice. Over three years later, we recognize each other easily—though I now sport the dark half-moons of sleepless college nights, and he’s grown a moustache, some faux-whiskers of his own. This morning, I find him at his desk, looking at blue and black figures on his computer; my guess is they’re microscope images. “You can always find me here, testing the limits of the zoom function,” he jokes, gesturing for me to take a seat.

Jake’s fascination with evolution is infectious. “Why do we have all this diversity?” he asks, his hands sketching invisible shapes in the air. Unlike the choice of styling one’s facial hair, most of our traits have developed over time, carrying evolutionary reasoning and lineage. From our thumbs to our toes, we owe our features to their hereditary character and the wonders of our adaptive nature. Scientists operate under the assumption that every hair on an animal’s body has a purpose. For Jake, whiskers are a key to understanding larger evolutionary puzzles.

If you stop to think about it, a lot of known things we take for granted are actually “these crazy adaptations” that he likes to talk about. Sweat for example. Humans do it as evaporative cooling, a trick we only share with horses. And while other mammals stop and pant to exhaust heat, we can breathe through our mouths and keep exercising. It’s fascinating to see what extra-oddities we’ve developed, but there are some trait clubs we have been excluded from.

“Humans are the only mammals that do not have whiskers.” Well, that can’t possibly be true! He grabs a marker and leads me to a whiteboard. He starts drawing phylogenetic trees, diagrams of organisms' evolutionary relations to one another.

“Let me correct myself: mammals at some point split into two, eutherian mammals that give live placental births and monotremes that don’t. Like the platypus or the echidna. Humans are the only eutherian mammals that don’t have whiskers. Even mammals that don’t have them as adults, like the dolphins, have whisker follicles early in life. A vestigial trait from their ancestors who had and used whiskers.”

Vestigial traits, from the word vestige, are obsolete remnants found in a species’ present form. Stored in the dusty corners of our biological attic, we humans still have a coccyx, wisdom teeth, the goosebumps reflex, to name a few.

With so many species under the Mammalia class, Jake spent the first weeks of his PhD at the museum, looking at hundreds of specimens from different sorts of populations. He chose Peromyscus maniculatus, the deer mouse. “They’re thought to be the most common and widespread small mammal in North America. I can watch them in the wild and have them in the lab, I can also track them through multiple generations.” A practical choice, certainly—but then he leans in as if to share a secret.

 “There is another important detail... the background, I guess: mice will actively sweep their whiskers around.” He extends his long fingers into jazz hands to mimic the movement. “Most mammals have static whiskers, something has to move or brush against them. Mice and other rodents have musculature in their snout so they can whisk while standing.” I giggle. I would have imagined that act as being called, if anything, whiskering. Jake does not seem as amused, whisking is serious business. Teams of engineers are trying to replicate whisking for robots, to map textures and stealthily navigate in the dark.

After leading research experiments for six years, Jake has learned a lot about the whiskers of deer mice, but his biggest focus has been their length. Deer mice split into two populations: forest mice and prairie mice. Despite having nearly identical habitats and behaviors, forest mice have longer whiskers. Why the difference? And more importantly, which gene is responsible for it? A month before defending his thesis, Jake is finishing a close analysis of the whisker follicle structure of both forest and prairie mice. I’ve seen him work before, but I’m most excited about today’s agenda. “To the lab!”

The Biology Laboratories on campus are something of a maze. Even after years of navigating these halls, I still get disoriented—both inside the buildings and outside in the courtyards, where winding paths and dead-ends seem designed to confuse. I can’t say for sure, but there might have been someone with a pair of binoculars on one of the higher floors, observing and taking systematic notes on my behavior. Jake’s experiments with mice, however, are nothing like the cinematic depictions of cheese mazes and escape antics.

Early in his PhD, he designed a study to test whether whisker length mattered in navigating environments. There were ramps, ledges, an infrared camera, a room in pitch-black darkness, the mice, and our scientist. It was called the gap-crossing test: mice climbed up a ramp, paused to sense a gap, then extended their snouts until their whiskers touched the opposite ledge. Only then would they reach out with their front legs to cross. Jake worked with 38 subjects—half forest, half prairie—and spent weeks observing their behavior. As he varied the gap distance, he began to see patterns: longer whiskers offered a clear advantage.

Then came the pivotal moment. “I trimmed their whiskers,” he says, almost apologetically.

In all of this, I continue to wonder at the amount of meticulous labor. How do you measure, trim, track differences in something so small? “I had to quickly learn how to hold the mouse with one hand, pinch the back of their neck, hold their tail between my pinky and ring finger, belly out. It’s a very niche skill, but I can easily identify individual whisker positions and measure them with digital calipers.” There’s incredible gentleness in how he’s holding the invisible mouse as he explains. “When I track whisker growth, I paint each whisker with UV-fluorescent dye.” It takes a while. At a conference, when a skeptical researcher doubted his precision, Jake’s collection of fluorescently dyed whisker photos silenced any doubts.

The lab is big, and at noon, light is flooding in. Jake leads me to an annex lined with ten freezers. He opens the middle one and, as I gape at the large drawers, he retrieves a small ball of aluminum foil. At a workstation on the opposite side of the lab, we sit before a microtome - a machine that resembles an oversized deli slicer. He carefully unwraps the foil, revealing a fragment of iced medium with a dark brown speck embedded within. “This is a whisker follicle I extracted a while ago,” he explains. “I didn’t like the images I took of it, so I’m redoing them today.” With practiced precision, he places the medium into a sealed chamber within the machine. The display reads -20 degrees Celsius. Jake adjusts a series of levers and dials with the focus of a craftsman until, satisfied, he pauses. “This gives me a sixteen-micron-thick vertical slice,” he says, rotating a small wheel. The blade makes an almost imperceptible movement. Jake deftly transfers the slice onto a glass slide with a delicate touch. Before it can be stained, the slide must return to the freezer for a few hours.

YouTube provides a rabbit hole of videos featuring wild deer mice hopping around fallen leaves. In one, a pink-manicured hand cradles a mouse pup no bigger than an olive, just a day old. There’s a full collection of whiskers already adorning the tiniest snout.

I ask if he sees the mice colonies these days. “Sometimes, but mostly, the lab tech handles them now.” Do they bite? “Oh, yeah. These aren’t domesticated lab mice—they’re wild. They’ll try to bite you or create chaos any chance they get. It’s funny; you think you’ve accounted for everything in your setup, but deer mice will always find a flaw. They’ll escape or throw a wrench into your plans. I haven’t been bitten in a while, though—I’ve learned.”

His tone shifts as he talks about them, with a clear admiration for their unpredictability, even their defiance. A hint of affection. As our conversation turns to the nearing end of his project, his words are tinged with exhaustion, softened by a sense of nostalgia for the whirlwind of challenges and discoveries that brought him here.

The slide, now frozen and ready, sits on the workbench as Jake carefully applies a sequence of solutions. “This fixes the tissue so it won’t degrade,” he explains while methodically pipetting liquids. Next comes a reagent to make the tissue permeable, followed by a fluorescent dye. “This dye attaches to certain structures—you’ll see.” He rinses the slide under running water and sets it aside to dry. Jake moves with an ease born of repetition, his motions deliberate and precise. I’ve heard people say pet owners often resemble their animals; watching him now, I wonder if the same can be said for researchers and their subjects. His restless energy seems oddly mouse-like, darting from task to task. Finally, the slide is ready and I follow him into a small, dimly lit room where the microscope and monitor glow against the darkness. “I’ve spent a lot of time in here,” he says, flicking a switch to adjust the light.

If the forest mouse whiskers are longer, there are only so many possibilities: the prairie and forest could grow at different rates, whiskers could start growing sooner, stop later, and so on. Jake measured his 40 rodents every day for 60 days. Newborn mice had whiskers but were too small to be accurately measured. He had to follow the growth another way and the answer starts at the follicle.

He places the slide under the microscope, and the image blooms onto the screen—a stunning matrix of blues against a jet-black background. “Whiskers are, after all, specialized hairs, keratinized cells with a hair follicle. At the base of the follicle, there is something called a dermal papillae, the structure that controls the growth. See this mass of blue dots? It marks dividing cells, so we can see it happening. Similarities with regular hair stop here, because these parts,” he switches lights on the microscope and now new areas on the image are highlighted in red, “are part of larger structures called blood sinuses. They’re like rigid capsule that makes the follicle highly sensitive to movement. These structures are packed with nerves, making whiskers incredibly adept at detecting disturbances.”

We switch more lights and go in-depth about the morphology and numerous components of the follicle. An un-updated LinkedIn photo taught me Jake once sported light blue hair, while a Facebook one taught me he plays guitar and has a bandcamp. But as we’re leaning over zoomed-in photos of a single brown speck, he whispers explanations about every structural detail. And Jake is not just describing this complex system—he’s marveling at it, sharing the awe that fuels his meticulous work.

When we emerge from the microscope room, the fluorescent lab lights feel harsher than ever, a jarring contrast to the hushed, glowing world we just left behind. We walk back to his office and it becomes clear that we might have outlasted the other scientists. His desk is in a casual state of controlled chaos—papers scattered across every surface, tabs multiplying on the computer screen like unchecked variables.

“I’m looking for gene expression patterns, I want to narrow it down to one responsible gene governing this trait,” he says, gesturing toward the mess. “Mice have about 24,000 genes, and around 16,000 of those will be expressed in the whisker follicle. My shortlist is down to fourteen” I think he senses my amazement tarnished by fatigue. “It’s hard, no question about it. Folks in the future will have clever ways to streamline this process. For now, it’s a long, arduous road—one trait, one gene, one experiment at a time.”

Yet, Jake isn’t ready to stop. “I’m sticking around after the defense,” he says, flipping between tabs on his screen. “There’s still more to finish.”

Next week, I’ll return to look at the latest data with him. As I leave, the image of his desk stays with me—papers like footholds, the screen glowing like a beacon. Jake Gable continues his ascent up the mountain of research, balancing on the tip of a whisker.