Tracking Humans as a Migratory Species

The will to migrate is rooted in the human genes for survival. This study tracks the natural dispersion of humans on the earth through open migration and freedom of movement, a right broadly recognized in the International Bill of Human Rights. The notion of open immigration seems radical because the ideology of sovereign borders rebuffs a wide-open planet. Before the rise of the nation-states, humans have been free to lay roots anywhere in the world. Humans as a migratory species apply their natural freedom to live anywhere they please, even though, ironically, most culturally conditioned humans settle with their families and seldom relocate. The freedom to migrate is available to wealthy families and individuals who own businesses and houses in several countries.Unfortunately, hundreds of poor migrants die in fragile boats and suffocative vans each year while striving to find a better life away from wretched conditions. While the poor migrants have no hosts, many developed countries engage in predatory migration with incentives to entice qualified workers, including doctors and engineers, from developing countries.

Throughout evolution, humans have been a migratory species plodding the earth. Human migration is rarely recreational; it is mainly necessity-driven. As such, human migration is no different from animal migration. Billions of animals engage in annual migration. Animals in search of food, better climate, mates, or in search of safety from predation, disease, and competition move away from their original habitats. Humans migrate for economic, physical, and religious survival for the most part. Modern migration acquires a more complicated motivation, including pursuing a higher standard of living, professional satisfaction, even existential adventure.

Human migration is a permanent change of residence. It is not the same as nomadism or tourism, which humans also do as expressions of migratory genes. This study does not discuss migrant workers who migrate across borders for remunerated work.

By offering physical security and other means to safeguard survival, the human civilization may have suppressed the migratory genes, much like animal habituation in zoos. The dynamics of society, such as culture, tribes, families, nations, and similar anchors, induce humans to settle and find solutions to problems locally. Consequently, some people would rather suffer, even perish, but not relocate. Most modern humans die where they are born. And yet evolution generating natural disasters and human conflicts continues to toss and throw humans on the planet.

The cultural suppression of migratory genes, though real, is not foolproof. Humans tied to families, nations, races, and religions seem stable, but they are in motion, as they have been, in the great vortex of history. Like everything else, what appears to be stationary is in motion. The earth moves in more than one way, though it seems deceptively flat and nonmoving. The electrons in the atom of a solid object are constantly spinning. Since time immemorial, humans have migrated in each generation for various reasons. According to the International Organization for Migration, 3.6% of the global population, over 280 million people, relocated in 2020. Elon Musk’s drive to send humans to Mars, though critics find it worthy of authentic derision, is consistent with the migratory genealogy of the species.

Historical Migration

Human migration is not a philosophical concept but an undeniable reality, a necessity for the survival of the species, a fact crystal clear in the annals of history. Suppose the DNA-based hypothesis of the African origin of modern humans is correct, under which homo sapiens began to migrate to other parts of the world 200 thousand years ago. In that case, the emergence of China, India, the Middle East, and Europe with significant but diverse populations proves that humans have gradually but unfailingly scattered their genes all over the planet, acquiring physical adaptability to local conditions. As opposed to scientific theories, sacred texts repose the origin of humans in Adam and Eve — a belief ratified in the Bible and the Qur’an. Similarly, the Hindu and Chinese creation stories trace humans back to a single source, Purusha and Pangu. These various scientific and religious beliefs suggest that humans descending from a single source, worldly or celestial, multiplied on the earth and spread in all directions.

In the past 400 years, human migration to the United States, Canada, Latin America, and Oceania fits well with the theme of evolution. Colonization, predation, war, natural disasters, human trafficking, oppression, and numerous other forces compel humans to leave one place for another. Even today, despite the nation-state barriers, humans migrate lawfully and unlawfully across the land and oceans. The United States hosts more immigrants than any other country, “with more than one million people arriving as permanent legal residents, asylum-seekers, and refugees every year.” The U.S. and Brazil, relatively recently flooded with immigrants in the evolutionary calendar, are in the top ten most populous countries.

Notwithstanding the nonsensical theories of racial superiority and ethnic hubris, the fact remains that lack of migration traps breeding populations in geographical territories. A race exists when a breeding population confined to a geographical region, such as Europe, China, or Africa, procreates within itself. The fusion of races occurs when races live together, a fact vivid in Brazil. The logic is simple. If whites reproduce with whites, the children will be white — a Yogi Berra’s déjà vu all over again. The miscegenation laws may prohibit interracial procreation, but such laws fail against the forces of evolution, as they have in the U.S.

Population Density

As presently constituted, the human dispersion on the planet is uneven, a random effect of historical events and cultural suppression of migratory genes. Consequently, population density (the number of people per square kilometer) varies worldwide. The Food and Agriculture Organization and World Bank population estimates show that South Asia, Western Europe, and the Middle East are teeming with humans crowded in close quarters. Bangladesh, Lebanon, South Korea, the Netherlands, and Rwanda are densely populated nations with more than 500 humans per km2. In contrast, Mongolia, Namibia, Australia, Canada, and Russia are sparsely populated, with less than ten (10) humans per km2. Some islands, including Hong Kong, Monaco, and Bahrain, are highly dense, with more than a thousand (1,000) humans per km2. The United States carries 36 humans per km2.

In addition to uneven historical distribution, the rise of cities and megacities has distorted human dispersion more than any other driver in human history. The population density dramatically varies between cities and the countryside. Cities with economic opportunities and cultural production attract millions of humans willing to surrender space and family connectivity. In countries where social planning is poor, attraction to cities generates human slums with substandard life far below human dignity. What forces humans to migrate to cities is the same as what prompts them to move to other countries: economic opportunity, conflict, persecution, natural disasters, family union.

There seems to be no intrinsic correlation between population density and superior economic development. Germany, for example, is a densely populated country with nearly $51,000 GDP per capita and zero slums. India is densely populated but with enormous slums around big cities. Bangladesh is listed as the least developed country on the U.N. charts despite its high population density being closer to the Netherlands, another G10 nation with over $54,000 GDP per capita.

Likewise, population sparsity does not lead to low economic development. Canada is a G10 country with over $45,000 GDP per capita, whereas Niger is one of the least developed countries. Canada and Niger have less than 20 humans per km2. In sum, sparse density does not preempt economic prosperity, nor does high density necessarily lead to the creation of slums.

However, congestion is an environmental hazard. Adding people to an already densely populated country may set off ecological problems. Pathogens circulate faster when humans live in close clusters. For centuries and long before the discovery of antibiotics and vaccines, infectious diseases killed humans in disproportionate numbers compared to other causes of death. Even a shift from hunter-gatherers to agricultural societies increased density and intensified infections. The zoonotic transmission of pathogens from animals to humans also multiplied with animal farming and animal trading. Despite healthcare advancement, the population density continues to threaten humans in cities and megacities, as evident from the spread of Covid-19, which attacked big cities far more severely than the countryside.

Because of varying human density across the planet, the right to freedom of movement and immigration needs rational management. It makes sense that countries with low population density are open to immigration. However, as discussed below, nations do not act rationally in the interest of the planet or the human species.

Freedom of Movement

Considering human migratory needs, international law explicitly recognizes every human’s inherent right to freedom of movement. Accordingly, humans may lawfully live anywhere within a nation and immigrate to another country. Note that international law emanates from the will of the world’s peoples expressed through governments. There is a universal consensus that the freedom of movement is part of human dignity; it is a right as good as freedom of expression and freedom of religion. The right to freedom of movement is incorporated in global and regional human rights treaties.

Article 13(2) of the Universal Declaration of Human Rights (1948) states: “Everyone has the right to leave any country, including his own, and to return to his country.” Read with its non-discrimination clauses, the Declaration grants “everyone” without any distinction of race, sex, religion, language, property, birth or other status “to leave any country” where the person is residing. The right implies that the person’s country of birth or residence must furnish a passport or other traveling documents for lawful departure. The person who leaves a country retains the right to return to “his country,” thus enjoying the full right to freedom of movement.

Article 12 of the International Covenant on Civil and Political Rights, a global human rights treaty fully binding on 173 countries, states in categorical terms: “Everyone shall be free to leave any country, including his own.” The Covenant further states that a person’s right to leave shall be subject to minimal restrictions such as national security or public health. The Covenant also recognizes the right to return, for example, that the Palestinians assert.

Regional human rights treaties, enforced in Europe, Africa, and the Americas, the right to leave, and the right to return are recognized in line with the International Bill of Rights. For example, the American Convention on Human Rights states: “Every person has the right to leave any country freely, including his own.” The American Convention prohibits deportation of any person without due process of law and does not allow deportation if the person faces persecution in the country of origin.

The right to freedom of movement is consistent with human migratory genealogy, but this right remains paper freedom since nation-states demonstrate no commitment to open migration. Even though immigration remains within the powers of sovereign states, the right to freedom of movement will continue to remind humans that they are free to relocate to other countries and continents, even planets.

Immigration Barriers

Although international law recognizes a robust right to freedom of movement, it does not obligate nations to allow open immigration. Most countries welcome tourists, but not immigrants. Governments are bound under international law not to prevent anyone from leaving the country, but they have no obligation to let people in. Nations control the arrival of “foreigners” through complicated visa classifications. A few nations have generous immigration policies, while others allow zero immigration for permanent resettlement. Unfortunately, some countries adopt explicit or implicit racist policies to influence immigration.

For decades, for example, Australia adopted race-based immigration policies under which only whites could resettle in the vast continent that Britain had colonized in 1788. Soon after colonization, Britain engineered the Australian migration by first shipping male convicts, later female convicts, and single women to support procreation. For seventy-two years (1901-1973), Australian governments adopted a migration policy to establish an “ethnically homogeneous society” and restricted migration from non-white countries. Like Canada, Australia now espouses multiculturalism and is more open to migration from India, China, the Philippines, and Malaysia. Still, the inflow from Africa to Australia is negligible.

In addition to legal restrictions, societies institute implicit obstacles to the inflow of foreigners. Culture, language, and religion serve as standard barriers to migration. (The people who oppose migration should know that migration is an emotionally trying option, and the author of this study can testify that living even as a successful immigrant is fretful.) However, the intensity of the barrier varies from culture to culture. Immigrating to a country where people are committed to a single faith or language or where locals are hostile to the presence of “aliens” is much more complicated than resettling in a pluralistic society.

Western countries’ migratory attraction is due to economic prosperity and accommodation of diverse religions and cultures, notwithstanding sporadic anti-immigrant sentiments advocated in various European countries. Overly religious nations may attract immigrants from countries with the same faith, but such nations do not draw diverse immigration. Some Gulf states have the stingiest immigration policies despite exploiting overseas labor in millions for decades. Ironically, millions of Arabs leave their homelands to resettle in the United States, Canada, and Europe.

Israel’s immigration policy is unique among nations. Since its establishment in 1948, Israel has enticed Jews from across the world to migrate to Israel. Millions of Jews from Russia, Europe, and the United States have settled in Israel, creating a population density of 426 persons per km2. Israel does not accept non-Jews as immigrants. Neither can Palestinians return to their homes in Israel. More than 1.5 million Palestinians live in refugee camps in Jordan, Lebanon, Syria, and elsewhere.

Likewise, Rohingyas have forcibly migrated from Myanmar, at times stranded in crumbly boats drifting through the Bay of Bengal. Bangladesh, a densely populated country, has settled the Rohingya refugees in the fragile island of Bhasan Char. Despite giving disingenuous sermons on the unity of Muslim ummah, rich and spacious Muslim nations have shown no concern for the poor and the wretched men, women, and children forced out of their homes by none other but the mantra-chanting Buddhist monks.

Distance, physical and cultural, has been a tremendous historical barrier to human migration. The early humans walked or used animals for resettlement. As humans settled in communities, they turned less prone to migration. Modern humans enjoy unparallel convenience in relocation. Motor vehicles and airplanes have resolved the distance problem to the extent of affordability. Immigrants can relocate thousands of miles away from their homes in a matter of hours. Information is readily available regarding jobs in distant lands. Yet, long-distance migration imposes huge cultural and emotional costs on migrants. It is no surprise that most immigrants from Mexico choose California, Texas, and New Mexico. Most immigrants from Cuba, who migrated en masse to “resist” the communist revolution, have landed in Florida.

Despite the availability of air travel, sovereignty plays a significant role in migration dynamics. In a world partitioned in nearly 200 nation-states, sovereign borders confuse the notion of migratory distance. A person migrating from Miami to Seattle travels more than 3,000 miles. Yet, the person is free to resettle within the sovereign borders. However, a person in Mexico is only a few miles away from a nearby town in the U.S. This short-distance migration faces huge legal hurdles because of sovereignty. In the European Union, which revoked the internal sovereignty of borders, the residents of member states can freely relocate across borders, regardless of distance.

Predatory Migration

In dead opposition to barriers are the incentives that nations market to attract migration. Exploiting the human migratory genes and the right to freedom of movement, some developed countries, in need of skilled labor, provide migration incentives for qualified individuals to leave their countries and relocate—a form of predatory migration. Many developed countries, including Japan, entice foreign workers in medicine, science, and technology fields by offering higher education, high salaries that migrants cannot receive in their own countries. For example, 25% of all physicians (247,000) in the U.S. hold medical degrees from foreign countries, many thousands from India and Pakistan.

Predatory migration fosters two troubling aftereffects. First, the cost of training physicians, engineers, and scientists falls on exporting nations, mostly poor, while the importing countries, mostly wealthy, receive qualified workers without any developmental investment. Second, the exporting countries lose talented people they desperately need to develop their socio-economic metrics.

Consider the U.S. importation of physicians. The number of physicians serving in the U.S. amount to 2.6 per 1,000 people. However, the number of physicians serving in India is 0.9 per 1,000 people and 1.1 per 1,000 people in Pakistan. The data suggest that India and Pakistan need to retain their physicians to improve domestic healthcare services. India and Pakistan also export vast numbers of engineers and computer scientists to developed countries. Thus, predatory migration leads to resource exploitation hidden under the legal cover of freedom of movement.

Fair Distribution of Humans

Any fair distribution of humans across the planet seems unlikely because even in economically prosperous countries, individuals are restless and want to relocate to another country for various reasons. The migratory genes, defying cultural suppression, prompt individuals to seek relocation for multiple reasons, including personal freedom and the pursuit of what Maslow called higher needs such as prestige, the feeling of accomplishment, and self-actualization.

According to a Gallup survey, 14% of the world’s adults (710 million) wish to migrate to another country. Most adults who want to migrate live in Eastern Europe, Sub-Saharan Africa, Latin America, and Arab countries. The adults seeking migration from Asia, the most densely populated continent, are relatively lower in population percentages. The primary reasons for migration are the same as they have been throughout history: famine, disaster, and disease. However, nearly 10% of North American adults and, surprisingly, 21% of adults in the affluent European Union also wish to migrate to another country, complicating the reasons for migration.

The U.S., Germany, Canada, the United Kingdom, France, and Australia remain the top countries that potential migrants from various parts of the world list as their preference. However, people in distress rarely insist on moving to a particular country, even when they have a preference. In most cases, they will be willing to move to a safe country where a dignified life is accessible.

Though it ranks high as a preferred destination for potential migrants, Germany is more densely populated than the U.S. and Canada. With low population density, Canada and Australia have the economic means to accommodate many more potential immigrants than Germany, the United Kingdom, and France, where density runs over 200 persons per km2. No country in Asia or Africa is a desired destination for potential migrants, except a few million adults express interest in South Korea, a densely populated country with 531 persons per km2.

Saudi Arabia and the United Arab Emirates also show up as desired destinations for potential migrants. Unfortunately, these countries have no interest in permanent residents. They welcome workers on revocable visas, and workers rarely qualify to become citizens after living their entire lives.

Africa –particularly countries such as Namibia, Botswana, Mauritania, Central African Republic, Gabon, and Chad — is wide open for migration, with fewer than ten persons per km2 in several resourceful countries. Unfortunately, the African experience with colonization and slave trade is still fresh in memories and on the ground. The 1972 mass expulsion of South Asians from Uganda backfired, and the economy collapsed. However, a few years later, the South Asians were allowed to return to their homes and businesses.

Ecologically, the planet would be much better off if there was a fair distribution of humans across the continents. Fairness also suggests that instead of moving to developed countries for comfort and luxuries, the engineers, computer scientists, economists, and physicians will do much good to themselves and humanity if they consider serving developing countries. International institutions, such as the International Organization for Migration, need to design a more rational plan for human relocation. They cannot leave migration to spontaneous reactions to natural disasters and human conflicts.


The will to migrate is deeply anchored in human survival instincts. Humans migrate to safer places when they face physical threats. Whether one believes in the scientific hypothesis of the African origin of homo sapiens or the religious creation theories of Adam and Eve, Purusha, or Pangu, the fact is inescapable that humans have multiplied and dispersed through migration. Over many millennia, historical forces have tossed humans in all parts of the planet. The current population density is mind-boggling as some countries are densely populated while others are not. The rise of cities and megacities has also greatly influenced the migration dynamics.

Many factors, including culture, family, and religion, have suppressed the human migratory genes as humans find more security and peace of mind in their own countries and cultures rather than moving far away to distant lands where people might be hostile. However, the uneven development among nations introduces a new factor to migration as skilled and unskilled labor from developing countries migrate to developed countries for higher salaries. Millions of adults in the affluent European Union and North America wish to migrate to other countries, which signifies that the migratory genes, now in search of Maslow’s higher needs, cannot be entirely suppressed.

International law recognizes the right to freedom of movement within and across the borders of nation-states. However, international law imposes no obligation on nations to accept immigrants who knock on their doors. While the poor and the wretched die in transit, wealthy individuals enjoy unprecedented freedom to live anywhere they please. Furthermore, developed nations experiencing a scarcity of skilled labor mobilize monetary incentives to draw migrants mostly from developing countries, engaging in predatory migration.

Ideally, a fair distribution of humans on the planet would require that sparsely populated countries, such as Canada and Australia, adopt a more generous immigration policy sponsoring young people from overly populated countries to relocate so that they can procreate in the host countries. This sort of migration might even be eco-friendly. However, humans as a migratory species make difficult resource-seeking choices: some rush to live in cities and megacities for jobs; some aspire to migrate to densely populated countries like Germany, Japan, and the United Kingdom; some are restless wherever they are. The U.S. remains the primary magnet drawing immigrants worldwide. However, the siren call that even millions of U.S. residents desire to move to another country “puzzles the will.”

L. Ali Khan is the founder of Legal Scholar Academy and an Emeritus Professor of Law at the Washburn University School of Law in Topeka, Kansas. He welcomes comments at