Akiva Topper watched a harmless Dasypeltis egg-eating snake in the Israeli desert rub its scales together, hissing and coiling like a venomous viper—despite no vipers being nearby. The performance was flawless, yet puzzling: why would a snake mimic a predator it had never encountered? The answer, now revealed in a groundbreaking study, reshapes how we understand evolution itself. Topper, along with Dr. Yotam Ben-Oren and Dr. Oren Kolodny of the Hebrew University of Jerusalem, has uncovered evidence that migratory predators can act as evolutionary bridges, linking species thousands of kilometers apart—species that never meet, yet still shape each other’s survival. Their findings, published in the Proceedings of the National Academy of Sciences, challenge a century-old assumption: that coevolution requires geographic overlap.
For decades, mimicry—the evolution of similar warning signals like colors, sounds, or behaviors—was thought to be a local game. A harmless species mimics a dangerous one only if both share the same predators in the same place. But Topper’s team used computer simulations to show something radical: when predators migrate, they carry their learned fears with them. A bird of prey that avoids a venomous snake in Thailand may later avoid a harmless lookalike in the Philippines, simply because it remembers the danger. In this way, migratory predators become evolutionary messengers, connecting distant ecosystems through shared avoidance.
The simulations modeled two separate populations of defended prey linked only by migratory predators. Results showed that even without geographic overlap, the prey evolved nearly identical warning signals—because the predator’s memory crossed continents. The study suggests this mechanism could drive Müllerian mimicry, where multiple defended species converge on the same warning traits, across vast distances. Factors like the timing of migration and the strength of local predation shaped how quickly these signals evolved, revealing a delicate balance between movement and adaptation.
But the implications stretch far beyond snakes. The researchers propose that migratory species could link plant-herbivore arms races in different regions, connect host-pathogen dynamics across continents, or even influence the spread of viral resistance. Monarch butterflies and milkweed, migratory raptors and venomous reptiles, viruses carried by birds—these could all be players in a global evolutionary network long overlooked. Migration, the team argues, isn’t just an ecological spectacle; it’s a hidden architect of adaptation.
This new perspective invites scientists to look beyond local interactions and consider the planet as an interconnected evolutionary theater. As Topper and his colleagues write, 'Migration is a major ecological process that moves vast numbers of animals and their effects between distant ecosystems.' And now, we begin to see that it may also move evolution itself.