Driving toward Banff National Park along the Trans-Canada Highway, you can read the landscape like a map written in evergreen. On the cooler, wetter northeast-facing slopes of the Three Sisters in the Canadian Rockies, Engelmann spruce dominates. Across the valley on the warmer, drier southwest-facing slopes of Grotto Mountain, white spruce takes hold. And researchers at the University of Calgary have just discovered something remarkable: these two distinct species use virtually identical genetic tools to adapt to these radically different environments—and the pattern repeats across thousands of kilometers of Canadian terrain.
The discovery matters because it reveals how species survive and evolve in the face of environmental pressures. When Engelmann and white spruce encounter each other in central British Columbia and Northern Alberta, they typically interbreed freely. But in the Bow Valley corridor west of Calgary, they remain stubbornly distinct, held apart by their fierce specialization to opposite sides of the same valley. Understanding how this happens—and what genetic machinery drives it—opens doors to practical applications that could strengthen forests facing climate pressures.
Dr. Sam Yeaman, a professor with the Department of Biological Sciences at the University of Calgary and corresponding author of the study published in Molecular Biology and Evolution, spent many days hiking the mountains west of Calgary alongside postdoctoral researcher Dr. Gabriele Nocchi to gather 384 samples from spruce trees across multiple valleys. "It's pretty remarkable seeing how similar the patterns in their genomes look," Yeaman says. "I was expecting there to be some degree of similarity, but the degree of similarity was pretty striking."
What makes this finding so striking is the consistency. Engelmann spruce lives in higher elevation montane regions with deeper snowpacks and warmer average temperatures, while white spruce thrives in colder, drier, lower-elevation boreal regions. Yet when researchers examined the genetic patterns across these vastly different environments, the same regions of the genome were being favored by natural selection in both species. The same evolutionary solution emerged repeatedly, across different valleys separated by vast distances, suggesting that climate—not chance—was writing this story. "Each valley is like its own little lab setting to see how evolution has played out," Yeaman explains. "These species colonized these valleys presumably independently, so if we see the same patterns pop up over and over again in each valley, that really strongly suggests that certain regions of the genome are particularly important."
The implications ripple outward. Foresters can now study which genes confer drought tolerance, potentially leading to improved tree-breeding programs as forests face mounting climate stress. More fundamentally, the research illuminates the basic mechanics of evolution itself—showing that adaptation follows predictable, repeatable pathways rather than the random chaos we might otherwise expect.
Yeaman says the team will continue sampling other valleys to deepen their understanding of which traits drive adaptation. For a world watching forests struggle under climate change, the message is quietly hopeful: nature has already written part of the playbook for survival. Scientists are just beginning to read it.