The Next Great Migration: The Beauty and Terror of Life on the Move

The news today is full of stories of dislocated people on the move. Wild species, too, are escaping warming seas and desiccated lands, creeping, swimming, and flying in a mass exodus from their past habitats. News media presents this scrambling of the planet's migration patterns as unprecedented, provoking fears of the spread of disease and conflict and waves of anxiety across the Western world. On both sides of the Atlantic, experts issue alarmed predictions of millions of invading aliens, unstoppable as an advancing tsunami, and countries respond by electing anti-immigration leaders who slam closed borders that were historically porous. But the science and history of migration in animals, plants, and humans tell a different story. Far from being a disruptive behavior to be quelled at any cost, migration is an ancient and lifesaving response to environmental change, a biological imperative as necessary as breathing. Climate changes triggered the first human migrations out of Africa. F