The World-Altering Mosquito – Part 2

How the mosquito created the market for slavery worldwide -- and also helped end it in America.

In his book The Mosquito: A Human History of Our Deadliest Predator, Timothy Winegard explores the fundamental role the mosquito, and more particularly, the diseases it spreads, played in the creation of the worldwide market in African slaves.

Malaria is one of the many parasites spread by the mosquito whose ill effects reverberate even today.  As Winegard writes:

Currently, it is estimated that endemic malaria costs Africa roughly $30–$40 billion a year in lost commercial output. Economic growth in malarious countries is 1.3% to 2.5% lower than the adjusted global average. Cumulatively, spanning the modern era after the Second World War, this equates to a 35% lower gross domestic product (GDP) than it would have been in the absence of malaria. Malaria sickens and cripples economies.

But going back a millennium, malaria did more than kill.  It incentivized human slavery by African warlords, who sold slaves they didn’t need to others around the world.  As Winegard explains, Africans, who uniquely lived among high populations of malaria-spreading mosquitos, at first came to benefit from an evolutionary genetic mutation that helped protect them from the dread disease by altering the shape of red blood cells in a way that made it more difficult for the malaria parasite to latch onto it:

Within only 700 years, our immediate evolutionary counteroffensive, which bewildered the [malaria] parasite, was to promote a random mutation of the hemoglobin [an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood] -- the cell became sickle (or crescent) shaped. Normally, healthy red blood cells are cast from a donut or oval template. The malaria parasite cannot latch on to the strange-shaped sickle cell.

Today, we know this mutation as “Sickle cell disease,” which predominantly affects those of African descent and makes it more difficult for the bodies of those afflicted to use oxygen.  But Sickle cell’s origin was relatively fortuitous in that it initially helped those who had it stave off malaria.  As Winegard writes:

Advanced by natural selection, sickle cell is a hereditary genetic mutation passed on precisely because it was originally a net benefit to the people who carried it. Yes, you read that correctly. The evolutionary design that nearly killed Ryan Clark [an NLF player who collapsed from lack of oxygen while playing in high-altitude and low-oxygen location of Denver, Colorado] was initially a lifesaving human genetic adaptation. Clark’s sickle cell, which first appeared in Africa 7,300 years ago in a female known to anthropologists as “Sickle Cell Eve,” is the most recent and well-known genetic response to falciparum malaria … Given that sickle cell both gives and takes away life, it was a hasty and imperfect evolutionary response to mosquito-borne malaria. What it reveals, though, is the sheer scale of the threat falciparum malaria posed to early humans and by extension our very existence: It was arguably the paramount evolutionary survival pressure on our species … The genetic distribution of sickle cell shadowed the spread of humans, mosquitoes, and malaria in and out of Africa. Today, there are about 50–60 million carriers of sickle cell worldwide, with 80% still living in its birthplace, sub- Saharan Africa. Regionally, there are pockets in Africa, the Middle East, and South Asia where upwards of 40% of the population harbor the sickle cell gene.

But then Winegard describes sickle cell’s connection to the spread of slavery:

The longer association of Africans with mosquito-borne diseases and their corresponding full or partial acquired immunities bent by natural selection would have severe repercussions during the dark days of slavery … [T]he transatlantic slave trade introduced Africans and deadly mosquitoes and their diseases to the Americas. These African slaves, fortified with their hereditary genetic immunities to malaria, including sickle cell, withstood the wrath of mosquitoes as compared to defenseless and vulnerable European laborers and indentured servants. Enslaved Africans became a valuable commodity on colonial outposts and plantations in the Americas. Africans survived mosquito-borne diseases to produce profit, thereby becoming profitable entities themselves.

Here's how that situation developed historically:

From its epicenter in Turkey, the Islamic Ottoman Empire expanded across the Middle East, the Balkans, and eastern Europe during the fourteenth and fifteenth centuries, and closed the Silk Road to Christian traders and European access to the Asian market. With an economic recession at hand, the great powers of Europe sought to reopen this crucial commercial lifeline by circumventing the increasingly vast and combative Ottoman Empire. After six years of pestering the monarchies of Europe for funding, King Ferdinand and Queen Isabella of Spain finally relented and agreed to back the first voyage of a mystic crackpot named Cristóbal Colon (as Columbus was known in 1492) to reestablish trade with the Far East. Columbus was willing to be the vanguard of such an enterprise to, as he put it, “reach the lands of the Great Khan.” He set sail with a satchel of royal letters of introduction and a stack of fill-in-the-blank trade agreements for tendering to Asian rulers … [Columbus’] voyages set in motion a chain of sweeping events … On the eve of the Columbian Exchange and the imminent European onslaught, only 0.5% of the land east of the Mississippi River in the United States and Canada was under cultivation. For European countries, this figure ranged from 10 to 50%! … With the introduction of commercial agriculture and dam building, European settlers unwittingly created a toxic environment for themselves by establishing ideal mosquito-breeding habitats. Entomologists have suggested that within a century of colonization, indigenous and imported mosquito populations increased by fifteen times, prompting Thomas Jefferson to ominously declare that the ravages of mosquitoes were immutable and “not within human control.” Malaria and yellow fever were soon rooted along the Atlantic seaboard of North America … Of the estimated 100 million indigenous inhabitants of the Western Hemisphere in 1492, a population of roughly 5 million remained by 1700. Over 20% of the world’s population had been erased. The mosquito, along with other diseases such as smallpox, was culpable of genocidal extermination … While I do not want to trivialize Spanish cruelty, known as the Black Legend, it did not play the main role in the cataclysmic demise of local populations. Across the Spanish dominion, malaria, smallpox, tuberculosis, and eventually yellow fever were the paramount killers. As a result, however, the mosquito, and the Spanish colonists to a much lesser extent, had wiped out the prospect of a substantial, self-reproducing Taino [local] labor force. As both Europeans and indigenous peoples succumbed to malaria and other diseases, alternative labor was needed to fuel the lucrative production of tobacco, sugar, coffee, and cocoa.

And who was selling slaves to others worldwide?  African warlords who enslaved other Africans:

African transport slavery only became a profitable replacement after local indigenous servitude was no longer an option … As malaria, and eventually yellow fever, helped to eliminate the feasibility of indigenous slave labor in the hotbed mosquito climates of the Spanish and other European empires, the transatlantic African slave trade flourished. Duffy negativity, thalassemia, and sickle cell provided the Africans hereditary shields against malaria. Many had also been previously seasoned by yellow fever in Africa, rendering them immune to reinfection. While these factors were unknown at the time, what was easily observable to European owners of mining operations and plantations was that African slaves were relatively unafflicted by malaria and yellow fever, and simply did not die at the same rate as non- Africans … The willingness of Africans to participate in the slave trade in Africa allowed it to flourish. Africans delivered fellow Africans into the clutches of European subjugation and servitude, something the mosquito made impossible for Europeans to do themselves. The mosquito would not allow Europeans to pluck Africans from their homelands. Without African slavery, New World mercantilist plantation economics would have failed … African leaders and monarchs began raiding traditional enemies and allies alike, solely for the purpose of capturing slaves to sell at a growing number of slave forts on the coast, operated by an increasingly broad range of European nationalities. The European demand was met by an African supply of African slaves … Although starting out as a trickle, as indigenous manpower declined, the importation of African slaves became a steady and ever-rising stream of human trafficking … In an unforeseen genetic, but nevertheless cruel, biting twist of mosquito-driven irony, these African traits of natural selection against mosquito-borne diseases ensured their survival, which ensured their enslavement.

The irony continued, however, into the American Civil War, which was fought by the North to end slavery:

During the Civil War, mosquitoes acted as a third army of sorts, and primarily aided the northern cause of preserving the Union, and, eventually, with the unfurling of Lincoln’s 1863 Emancipation Proclamation, aided in abolishing the very institution of slavery she herself helped to create … According to Surgeon General William A. Hammond, it was a “well-ascertained fact” that Africans were “less liable to the affections of malarious origin than the European.” Of the roughly 200,000 African Americans who eventually served in Union forces, two-thirds had formerly been southern slaves. With their newfound freedom [under the Emancipation Proclamation], they enlisted to ensure the emancipation of their captive brethren by fighting on the front lines and battlefields of a war that was now being waged to decide the fate of slavery itself … Having squeezed the Confederate fortifications at Vicksburg with a Union line stretching 15 miles and unsettled by two fruitless yet costly frontal assaults on entrenched defenders, [Union General Ulysses S.] Grant initiated his siege on May 25 [1863] -- directly at the onset of mosquito season. Grant, however, knew he had an advantage that the depleted and besieged defenders of Vicksburg did not. While he had proven himself willing to leave his rations and supply depots behind, there was no way he was slogging through to muck about the swamps of Mississippi without stockpiles of quinine. One of the most important munitions in the Union’s arsenal was its abundant supply of this antimalarial medication. “The advantage this drug gave to Union forces cannot be overstated,” emphasizes [Andrew McIlwaine] Bell. “In fact,” he says of his own book [Mosquito Soldiers: Malaria, Yellow Fever, and the Course of the American Civil War], “one could argue without too much hyperbole that a more appropriate subtitle for this book might have been ‘How Quinine Saved the North.’ ... The Confederacy, on the other hand, experienced quinine shortages for most of the war, which meant that malarial fevers among Rebels went unchecked more often than not. Southern civilians also suffered.” Over the course of the war, the Union dispensed 19 tons of refined quinine and 10 tons of unrefined cinchona bark to its soldiers as both a treatment and a prophylactic for malaria. For the Confederacy, however, “the effectiveness of the Union naval blockade meant that southern surgeons ... suffered from quinine shortages for most of the war,” says Bell. “Given the prevalence of malaria in the South, it is astonishing that any Confederate troops were healthy enough to fight by the end of the war, when Richmond’s quinine supplies were extremely low.” This precious quinine certainly did not trickle down to the troops on the battlefield. Confederate politicians, including Jefferson Davis, had healthy stocks of quinine tucked away for themselves and their families. Ironically, while the naval blockade halted yellow fever, it allowed malaria to thrive. The astronomically increasing price of quinine in the Confederacy throughout the war attests to the cumulative effects of the Union blockade. It also signals that the smugglers knew just how crucial and sought-after the diminishing supply of the medicine was to a southern population suffering from unrelenting endemic malaria. In the opening year of the war, an ounce of quinine averaged $4, increasing to $23 by 1863. At the close of 1864, on the black market supplied by blockade runners, the price per ounce ranged from $400 to $600. By war’s end, quinine smugglers operating out of the Caribbean were making an incredible 2,500% return on their initial investment … “That the Confederacy suffered from a shortage of quinine in the war,” stresses Margaret Humphreys, physician and professor at Duke University’s School of Medicine, “made a significant difference in the number of men able to render military service … The Union blockade then caused an acute shortage of quinine to the South, leveling the playing field further.” … Although Confederate records went up in smoke with the fall of Richmond, the chief surgeon of the Confederacy knowledgeably estimated that of the 290,000 military fatalities, 75% were caused by disease. We can only guess at the total malarial impact on Confederate troops. The consensus among Civil War historians is that malaria rates and deaths were roughly 10% to 15% higher than those of Union forces.

This concludes this essay series on the mosquito’s influence on history.

Links to all essays in this series: Part 1; Part 2.