The Currents of Migration

An Essay on Human Migration in History

“Everything is related to everything else, but near things are more related than distant things.”

Waldo Tobler, American-Swiss Geographer (1970) First Law of Geography

Posted May 17th, 2019

As we’ve followed the progression of life across billions of years of history, we’ve come across many examples of the importance of migration and its central role in the diversity of life on Earth.

From the Woolly Mammoth’s vast metropolitan population spread across the steppe, to the rise and fall of thousands of species of tiny foraminifera in the ocean, each of these stories plays out on a grand scale that often encompasses hundreds of thousands of years. On this scale, small changes to these patterns of movement can have dramatic effects resulting in the emergence of new species and the extinction of the old.

We, as human beings, are not immune. On the contrary, our own story is a vibrant example of how powerful the effect of migration can be on a single species and the environment of an entire planet.

The map below was published in 1889 in the Journal of the statistical society of London. It was accompanied by a paper titled The Laws of Migration. Created by geographer, Ernst Georg Ravenstein, the Laws of Migration established a working framework for the statistical study of human migration as it relates to economic and population development.

Currents of Migration by Ernst Georg Ravenstein (1889)

The study is breathtaking in its scope, covering data from Great Britain, Europe, Canada, and the United States. Though published nearly 130 years ago, Ravenstein’s findings are still considered valid today:

The Laws of Human Migration

  1. Most migrations occur over short distances.
  2. Migration often happens in stages, moving from one center to another, steadily rising from rural to large urban centers.
  3. Most migrants are adults.
  4. Within a country, females are more migratory, though males are more likely to travel long distances.
  5. Long-distance migration typically involves a move to urban areas.
  6. Urban areas grow more by migration than natural increases.
  7. Urban dwellers are less migratory than rural populations.
  8. Economic factors drive most migration.
  9. Each migration produces measurable, though not necessarily equal, movement in the opposite direction.

When we look back into the deep past, it’s interesting to consider how these findings might apply to the movement of our close relatives. There is ample evidence to suggest that small migrations were common, moving with the seasons as nomadic peoples do today. But what of larger moves? Crossing continental divides and entering forbidden lands?

In 2018, Paleogeneticist Viviane Slon of the Max Planck Institute in Leipzig published a groundbreaking study of the remains of a girl born to Neanderthal and Denisovan parents 90,000 years ago. The discovery is part of a large cache of ancient human remains discovered in the “Denisova Cave” located in the Altai mountains of Siberia, Russia.

A view from the deep past... The Denisova Cave and the surrounding countryside of the Altai mountains in Siberia, Russia. (Image Credit: Ruslan Olinchuk)

Neanderthals and Denisovans separated genetically roughly 400,000 years ago (200,000 years after separating from us). Yet, genetic studies of this unique individual’s parents indicate that migrations between Eastern and Western Eurasia were frequent enough to suggest that mixing between these different hominin populations was not unusual.

We know nothing of the Denisovans physical appearance, aside from a few fragmentary remains. However, the DNA extracted from these tiny samples and compared with modern descendants (i.e. us) show they made their way down to the islands of Southeast Asia, New Guinea, and Australia. There are also suggestions that a third — and still undiscovered — hominin may also play a role in the diverse genetic makeup of the modern human species. While it’s still impossible to say where this story will lead us in the future, it is clear from even these early findings that migration has played an enormous role in our journey to the present.

Today the currents of migration are as powerful as ever and show no signs of slowing. Rather, the pace is accelerating and the scale is exponential.

A close-up view of the Za'atri camp for Syrian refugees as seen on July 18, 2013. It is the world's largest camp for Syrian refugees.

Countrysides around the world are emptying as rural populations move to urban centers. As these locations become increasingly dense, the waves of people move on, crossing borders and oceans, and entering new countries or entirely new continents.

According to the United Nations’ 2017 International Migration Report, 258,000,000 people now live in a country other than their birth. This is a 17% increase from the year before and a 49% increase since the year 2000.

The UN report also indicates that 42% of the net positive population gain in North America during the period of 2000-2015 can be attributed to migration. In Oceana, the figure is 31%. Reflecting on this data, Ravenstein’s observation about migration in the “New World” vs the “Old World” is particularly instructive:

"Another difference is this: whilst with us in Europe the "foreign element" constitute as mere fraction of the population, it assumes vast proportions in the new world.

Here in Europe every inflow of foreign elements is largely compensated by an outflow of natives, but in the new world the inflowing currents are overpoweringly strong, whilst the compensatory countercurrents are of the feeblest proportions.

These differences should constantly be borne in mind when discussing the statistics of American migration. They have been most marked in the past, and are very striking still. In course of time, however, they will become less glaring, until at last the new world shall have become assimilated to the old in its migratory currents no less than in other respects depending upon the population having attained a density commensurate with the natural resources of the country." ~ Ravenstein p. 278

In response, natives of a region move to erect borders and barriers that are both physical and conceptual. They try to restrict the inflow, but if history is any guide it is not truly possible.

"Speaking broadly, persons of foreign birth are most numerous in the frontier departments and in certain maritime towns. Their nationality in these localities corresponds with that of the nearest foreign country, in fact, as concerns migration, political boundaries do not appear to exist: Germans, notwithstanding the hostile feeling supposed to be entertained towards them, have nevertheless crossed the frontiers in considerable numbers, whilst natives of France have not allowed themselves to be deterred by rigorous passport regulations from crossing the French boundary into neighbouring parts of Germany." ~ Ravenstein p. 271

The people will still come regardless of all obstacles placed in their path.

Hundreds of refugees make their way to Macedonia from a makeshift camp at the Greek-Macedonian border, near the Greek village of Idomeni. (Image Credit: Orhan Tsolak Alamy Live News Idomeni, March 14, 2016)

They will enter forbidden lands. They will come regardless of hostile attitudes, disregarding the threat of physical harm and even the possibility of death. Perhaps it is because the way back is worse than the way forward, or perhaps it is simply the momentum of the current that carries them onward.

In the Second Edition of the Mini Museum, we touched on the fall of Bronze Age civilizations in the Eastern Mediterranean over 3,000 years ago. During this period, there were massive movements of people coming to population centers from many directions. Usually referred to as the “Sea People”, this diverse group is said to be responsible for the destruction of numerous cities and regions.

The Egyptians recorded their resistance on the walls of the mortuary temple of Ramesses III at Medinet Habu. All around the temple there are great murals depicting the effort expended in repelling waves of people.

The images of prisoners captured during the “Battle of the Delta” copied from the walls of the East Gate at Medinet Habu. The hieroglyphic names translate to Peleset, Tjeker, Shekelesh, Denyen, Weshesh, Sherden, and Teresh but their meanings are mostly lost to time.

But who were these people? What were they seeking? The records are sparse, but a complex picture of migration is slowly emerging; people forced to move by changes in climate, warfare, mercenary desire, and no doubt dire need to face such forces.

"Those who reached my boundary, their seed is not; their hearts and their souls are finished forever and ever. As for those who had assembled before them on the sea, the full flame was their front before the harbour mouths, and a wall of metal upon the shore surrounded them. They were dragged, overturned, and laid low upon the beach; slain and made heaps from stern to bow of their galleys, while all their things were cast upon the water."

~ Attributed to Ramses III from the inscriptions at Medinet Habu

It isn't hard to imagine that their stories are at heart no different from those who make similar perilous journeys today, or perhaps even that of Ernst Georg Ravenstein himself.

Ravenstein was born on December 20, 1834 in Frankfurt am Main, Germany. His father was a noted cartographer, and young Ernst trained in the discipline until the age of 18 when he immigrated to Great Britain. Upon arrival, he was apprenticed to another young German expatriate named August Heinrich Petermann. Petermann had arrived just a few years before and set up his own cartography business.

Ernst Georg Ravenstein (1834-1913)

The connection between the journey of Ravenstein and Petermann may seem conveniently matched, but in reality they were both part of an enormous wave of immigrants who left Germany over the course of the 19th century. During this time, Germany suffered numerous setbacks and upheavals from the aftermath of the Napoleonic Wars, and environmental havoc caused by the eruption of Mount Tambora in 1815, to the failed Spring of Nations Revolutions of 1848, and ongoing struggles throughout the rest of the century.

Most German immigrants during this period headed to North America, and the United States in particular. In the United States, Germans settled in large coastal cities such as New York and Baltimore, but many more settled in midwestern cities such as Milwaukee, Cincinnati, St. Louis, Chicago, and others. By 1900, numerous cities throughout midwestern part of the country had dominant populations of now German-Americans.

In Great Britain, the destination of choice was London with smaller communities in Manchester and elsewhere. As with communities in the United States, the Germans relocating to Great Britain developed a vibrant community based on their own cultural traditions, but over time they became business owners and deeply integrated into all levels of society.

Like other German immigrants, Ravenstein worked hard to contribute. Three years after he immigrated, Ravenstein joined the Topographical Department of the British War Office where he served for 20 years before embarking on a remarkable 35 year career as one of the preeminent cartographers in Europe. He produced the first detailed maps and studies of equatorial East Africa, and learned Portuguese so that he could research and write a detailed account of Vasco da Gama's first voyage of 1497-1499 from Portugal to India. The culmination of his life's work led to his receipt in 1902 of the first Victoria gold medal of the Royal Geographical Society which recognized "his efforts during 40 years to introduce scientific methods into the cartography of the United Kingdom."

After nearly 60 years abroad, Ravenstein returned to Germany. He passed away on March 13, 1913 in Hofheim, just outside his native Frankfurt. Only a little more than a year after his death, the outbreak of World War I would result in one of the largest displacements of human beings in history, and the aftermath would change immigration policies and controls around the world.

Yet where one avenue of migration ends another begins, and looking back to the UN report we can see that the currents of migration press onward. And why might that be? For Ravenstein the answer would be clear:

Most German immigrants during this period headed to North America, and the United States in particular. In the United States, Germans settled in large coastal cities such as New York and Baltimore, but many more settled in midwestern cities such as Milwaukee, Cincinnati, St. Louis, Chicago, and others. By 1900, numerous cities throughout midwestern part of the country had dominant populations of now German-Americans.

"Bad or oppressive laws, heavy taxation, an unattractive climate, uncongenial social surroundings, and even compulsion (slave trade,transportation), all have produced and are still producing currents of migration, but none of these currents can compare in volume with that which arises from the desire inherent in most men to "better" themselves in material respects." ~ From the Conclusion of The Laws of Migration

Art of the Erdapfel (or "Earth Apple") the oldest surviving globe, created by Martin von Behaim (1459-1507) and reproduced by Ravenstein in 1908 for his final book Martin Behaim: His Life and his Globe

We'll close this essay with Emma Lazarus' (1849–1887) sonnet, "The New Colossus" which was written in 1883 to raise funds for the construction of the Statue of Liberty's pedestal. The text of the sonnet was cast onto a bronze plaque in 1903 and appears on the inner wall of the pedestal:

This type of meteorite is distinguished by calcium–aluminium-rich inclusions (CAI), minerals that are among the first solids to condense in the high temperature gases of a young, protoplanetary disk. In addition to CAIs, Murchison also carries a fantastic array of more than 70 different amino acids, including 8 of the 20 proteinogenic amino acids used to build proteins encoded in our DNA as well as all life here on Earth.

Not like the brazen giant of Greek fame,
With conquering limbs astride from land to land;
Here at our sea-washed, sunset gates shall stand
A mighty woman with a torch, whose flame
Is the imprisoned lightning, and her name
MOTHER OF EXILES. From her beacon-hand
Glows world-wide welcome; her mild eyes command
The air-bridged harbor that twin cities frame.

"Keep, ancient lands, your storied pomp!" cries she
With silent lips. "Give me your tired, your poor,
Your huddled masses yearning to breathe free,
The wretched refuse of your teeming shore.
Send these, the homeless, tempest-tost to me,
I lift my lamp beside the golden door!"

Unveiling of the Statue of Liberty Enlightening the World by Edward Moran (1886)

Further Reading:

Ravenstein, Ernst Georg. "The laws of migration." Journal of the statistical society of London 48.2 (1885): 167-235.

Tobler, Waldo. "Migration: Ravenstein, Thornthwaite, and Beyond." Urban Geography 16.4 (1995): 327-343.

Turney, Chris SM, and Heidi Brown. "Catastrophic early Holocene sea level rise, human migration and the Neolithic transition in Europe." Quaternary Science Reviews 26.17-18 (2007): 2036-2041.

Cline, Eric H. 1177 BC: The Year Civilization Collapsed. Princeton University Press, 2014.

Slon, Viviane, et al. "The genome of the offspring of a Neanderthal mother and a Denisovan father." Nature 561.7721 (2018): 113.

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