Why movement is essential for survival – for animals and for humans

Meara Sharma

THE WASHINGTON POST – In the mid-20th Century, scientists began studying a population of wolves on an island in Lake Michigan in the United States (US). Over the ensuing decades, the wolves developed widespread spine deformities and eye abnormalities, probably a result of interbreeding and insularity, and began to deteriorate. But in 1997, a newcomer – a single male wolf – managed to journey over to the island. His arrival heralded a major shift for the local population, which, with this much-needed burst of genetic novelty, saw its ranks revitalised. The continuation of life hinged on migration.

Science journalist Sonia Shah unspools many such stories in her new book, The Next Great Migration: The Beauty and Terror of Life on the Move. In this sprawling exploration of our propensity toward movement, reported from Himalayan villages to Greek islands to the arid hills of Southern California, Shah argues that migration is a deep-rooted feature of the human and animal world, more fundamental and pervasive than we tend to think, and essential for our survival.

In our moment of ecological and political turmoil, mass migration is often framed as a grave crisis. The numbers are certainly staggering – some 60 million people have recently fled wars, persecution and the effects of climate change, a figure that could rise to one billion by 2050 – and we are familiar with politicians who cast migrants as criminal scourges, faceless hordes flooding Western shores or, as Robert D Kaplan put it in his 1994 Atlantic article, The Coming Anarchy, “loose molecules in a very unstable social fluid.”

However, Shah offers a refreshing and crucially humane counterargument to the idea that migration spells societal catastrophe. Interweaving the human history of movement with parables from nature, she reframes migration not as an exception in an otherwise static world but instead as a biological and cultural norm – and one that should be embraced, not feared.

“For centuries,” Shah wrote, “we’ve suppressed the fact of the migration instinct, demonising it as a harbinger of terror. We’ve constructed a story about our past, our bodies, and the natural world in which migration is the anomaly. It’s an illusion. And once it falls, the entire world shifts.”

Much of the book delves into the origins of this myth of a rigid world and its reverberating effects on public discourse and policy. Shah begins by investigating the work of 18th Century taxonomist Carl Linnaeus, whose system of classifying the living world tied each species to a particular place. Linnaeus was guided by the belief in a hierarchical, fixed natural order of things, a line of thinking that ultimately won out over that of his rival, French naturalist George-Louis Leclerc de Buffon.

The book traces how this early emphasis on the geographical differences between species helped give rise to “race science” and the eugenics movement of the 19th and 20th centuries. As millions of immigrants from Europe, Asia, the Caribbean and Central America arrived at New York’s ports, worried elites such as Madison Grant stoked panic about “hybridisation” and the “germplasm” of immigrant bodies, which would supposedly contaminate the stock of the nation. Shah describes a frenzied quest among race theorists to find scientific justification for their ideologies, a silver bullet that could put a stop to immigration.

Such research largely fizzled, never materialised or actively undermined racist hypotheses; however, the construction of migrants as poisonous and biologically inferior seeped into popular and political culture nonetheless. Grant’s 1916 book, The Passing of the Great Race, which declared the risks of upending racial hierarchies through migration, helped lead to a 1924 law that radically restricted nonwhite immigration to the US, and it was a template for Adolf Hitler.

Shah follows these ideologies as they echo through the decades, demonstrating how xenophobia, population control, environmental conservation and white supremacy have intersected and fuelled systematic efforts to restrict the movement of peoples and establish a “Linnaean vision of nature, in which biologically distinct peoples lived separately in geographically distinct locales”, a position that leads directly to the Trump administration’s immigration policies, as Shah points out. She quotes one of the president’s national security officials as saying: “Diversity is not our strength. It’s a source of weakness, tension, and disunion.”

Shah contrasts this vilification of migration with science that elucidates our profound wandering instinct. She explores how the “myths of a sedentary past and a racial order” began to crack, from 1980s research that revealed our common ancestry in Africa and the mass migrations that followed, to more recent breakthroughs that indicate even earlier waves of migration by ancient humans and other surprising journeys.

For example, “the five-thousand-year-old remains of a farmer buried in southern Sweden turn out to be genetically related to people living in Cyprus and Sardinia today. Modern-day Native Americans turn out to share genes with the Chukchi people of northeastern Siberia, suggesting their ancestors’ migrations from Asia into the Americas and then back again.”

Shah maintained: “We weren’t migrants once in the distant past and then again in the most recent modern era, with a long-defining period of stillness in between. We’ve been migrants all along.”

We underestimate the capacity for movement among wild species as well, Shah insists, illustrating her point with tales of leopards traversing multiple countries, Florida manatees drinking from Cape Cod marinas and biologically comparable trees separated by about 11,000 miles of ocean, among many others. Such parallels are intriguing but not always sound: In an effort to prove her thesis, she lumps together a host of reasons that species move – from annual cyclical journeys to human-caused habitat destruction – under the banner of migration.

She largely dismisses the notion of “invasive” or “non-native” species as the natural world’s analog for anti-immigration rhetoric, without engaging seriously with the ways in which ecosystems have been severely damaged by introduced flora and fauna. Focussed on celebrating migration, she avoids reckoning with the ecological harm roving humans have done to the planet, the effects of which we are confronting with increasing intensity.

There’s an obvious irony to reading a global history of migration in this time of global stillness, when most of us have been confined to our immediate surroundings for months. Shah describes how our xenophobic tendencies may be an embedded immune response to the fear that outsiders carry novel pathogens, a disturbing theory in the midst of a pandemic that has heightened our divisions.

However, “if we were to accept migration as integral to life on a dynamic planet with shifting and unevenly distributed resources, there are any number of ways we could proceed,” Shah wrote, briefly touching on schemes such as permeable borders, legal pathways for migrants and wildlife corridors to stitch together broken biomes. As we begin to emerge from this forced suspension, perhaps newly ready to move, Shah’s book is a provocative invitation to imagine the inevitable migration of the future as an opportunity, rather than a threat.