Friday, May 15, 2020

Wild Free and Happy Sample 39

[Note: This is the thirty-ninth sample from my rough draft of a far from finished new book, Wild, Free, & Happy.  The Search field on the right side will find words in the full contents of all rants and reviews.  These samples are not freestanding pieces.  They will be easier to understand if you start with sample 01, and follow the sequence listed HERE — if you have some free time.]


On the following pages, I’ll be jabbering a bit about different categories of diseases, and take a quick peek at some common examples.  Please remember that the primary purpose of this book is to compare and contrast wild humans with the less-than-wild mobs that emerged later — from the perspective that wild was our normal and natural state, and life as we now know it is the opposite.  There is an enormous difference between the two groups with regard to human health, and with regard to the health of the family of life.

Big Mama Nature lovingly fine-tuned our evolution.  Our ecological job description was to live as nomadic hunters, scavengers, and foragers who traveled in small groups.  Our natural habitat was open grasslands and forest edges.  In this manner, our hominin ancestors lived for several million years without radically disturbing fundamental balances in the family of life.  This, of course, is the norm for every member of the family.

Along the way, some clever ancestors got lost and confused.  By settling down, and crowding together in villages, towns, and cities, they developed a way of life that was at odds with our job description.  Over time, the quirky experiment grew and grew, and became ferociously unsustainable.  We sort of became herd animals, but not in a healthy wild way.

Herds of wild buffalo and horses have the inherent intelligence to follow their stomachs and keep moving.  They roam over the hill to where the grass is greener, and leave their shit behind to nurture the grass for future visits.  Herds of city dwellers generate enormous filth, at the same time they cause irreparable damage to the ecosystem.  This great “advance” in lifestyle triggers a whopping number of unintended consequences.  Let’s take a stroll down Pathogen Lane.


Richard Manning discussed what paleontologists have learned from old bones.  The bones of hunter-gatherers are boring to study, because most of them were very healthy.  Living in roadless wilderness, amidst man-eating predators, and using wooden spears to kill large strong animals, led to a lot of broken bones and premature deaths.  Folks did not spend their lives in climate-controlled compartments, or drive across the land in large motorized wheelchairs.  They inhaled a lot of smoke from their fires, which likely led to respiratory problems.  In warm regions, they were more vulnerable to intestinal parasites.

The bones of folks from agricultural societies were more interesting.  Their diet was far less nutritious than that of hunter-gatherers.  Until the last century, agricultural peasants spent their lives performing backbreaking labor, living in filthy conditions, and eating a low quality diet.  Many lived on bread and water alone, or oat porridge.  Meat was a rare treat.  This diet often led to illnesses from mineral and vitamin deficiencies, like pellagra, anemia, and thyroid problems.

Grain eaters commonly suffered from tooth decay, bone deformities, malnutrition, osteomyelitis, periostitis, intestinal parasites, malaria, yaws, syphilis, leprosy, tuberculosis, anemia, rickets in children, osteomalacia in adults, slow childhood growth, and short stature among adults.  Let’s take a look at a few diseases of malnutrition.


Rickets is a disease of severely malnourished infants and children.  Their bones are soft, are easily fractured, and can grow abnormally. Rickets is common in a number of developing nations.  We get vitamin D when we consume foods like butter, eggs, oily fishes, fish liver oils, and fortified milk.  Our skin cells use sunlight to convert vitamin D into a usable form, which enables our bodies to properly absorb calcium.  When this doesn’t happen, dental and skeletal deformities can develop — knock-knees, bowlegs, bulging foreheads, or narrow pelvises that interfere with normal childbirth.  In the early days of the Industrial Revolution in London, heavy smog, combined with persistent fog blocked a lot of sunlight.  At times, up to 80 percent of children had symptoms of rickets.


Pellagra is caused by chronic niacin deficiency (vitamin B3).  Its victims suffer from diarrhea, dermatitis, and dementia.  If not treated, death often occurred in 4 to 5 years.  Pellagra was common prior to the 1920s, at which point folks discovered that it could be easily cured by a diet that included daily servings of milk, eggs, or meat. 

In northern Italy, the poor lived primarily on boiled cornmeal, polenta.  In the U.S. south, pellagra was common among poor folks whose diet majored in cornmeal, molasses, and sowbelly (fat salt pork from the belly of a pig).  Pellagra was especially common in orphanages, sanitariums, asylums, and prisons, according to Burton Hendrick.  Between 1906 and 1940 more than 3 million Americans had pellagra, and more than 100,000 died.  Around the world, in the eighteenth and nineteenth centuries, hundreds of thousands died from pellagra.

Corn (maize) is an incredibly productive crop.  It is an excellent storage food when the kernels are properly dried.  Corn is deficient in two essential amino acids: lysine and tryptophan.  Native Americans learned that corn was far more nutritious when cooked along with an alkali like lye (leached from wood ashes), or lime (limestone: calcium carbonate).  This unlocked the niacin, making it available to the body.  Treated corn is called hominy.  A diet that includes both hominy and beans is even more nutritious.

Some believe that that the invention of hominy was revolutionary, beginning in the eastern U.S. around A.D. 750 to 800.  It greatly increased carrying capacity, leading to a surge in population, which enabled the rise of Mississippian civilizations like Cahokia and Kinkaid.  On the downside, hominy eaters experienced far more tooth decay.


Scurvy is caused by a deficiency of vitamin C (ascorbic acid) in the diet.  This vitamin is found in many fresh fruits and vegetables, especially citrus fruits, like oranges and lemons.  Potato eaters also get adequate vitamin C.  Before potatoes became a staple in northern regions, scurvy was common in winter months, when fresh foods were unavailable.  Homo sapiens are tropical primates, and if we had remained in tropical regions, scurvy would never have become an issue.

In the old days, when sailors spent months at sea, living on hard biscuits and salted meats, many got scurvy — until the British discovered the healing power of limes, and their sailors got the nickname Limeys (lemons have more C than limes).  After several months of insufficient vitamin C, folks experienced fatigue, and soreness and stiffness of the joints and lower extremities. Then came bleeding gums, loose teeth, bleeding under the skin, and personality changes.  Untreated, bleeding or infections led to death.


Beriberi means “extreme weakness.”  It is caused by a thiamine (vitamin B1) deficiency, and leads to impairment of the heart and nervous system, in both infants and adults.  It is common where diets major in polished (white) rice, and little else.  The rice husk is removed to greatly extend storage life, but the husk contains thiamine.  Beriberi is still common in some locations, like prisons.  It’s getting less common in Asia, where many are now eating better diets.  Untreated, it can cause death.  Half of the men in the Japanese navy got beriberi before 1880, when extra meat, fish, and veggies were added to their diet.


Cholera originated in tropical regions.  It is a fecal-oral disease caused by bacteria.  Its primary reservoir is marine organisms.  Sources of infection include contaminated food, water, and contact with the feces of cholera victims.  Symptoms can appear as soon as two hours after exposure, and victims sometimes die the same day.  The most common symptom is diarrhea, up to 3 to 5 gallons per day (10 to 20 l).  Once the bacteria enter the water supply, the disease rapidly spreads.

Victims primarily die from dehydration.  When provided with adequate amounts of water, victims often survive.  In severe cases, treatment with antibiotics and hydration can stop the infection.  Some strains of the bacteria have developed multiple drug resistance (MDR) — they can survive exposure to two or more types of antibiotics.  There are vaccines that can prevent cholera, but they do not provide lifelong immunity.

The first cholera pandemic began in Bengal, India, in 1816, and lasted until 1823.  So far, there have been seven global pandemics.  The second global pandemic ran from 1829 to 1851.  It spread to London and Paris.  Cholera was unable to spread to the Americas until 1832, when speedy new steamships enabled the pathogen to survive the voyage.  Once in Canada, it rapidly spread, transported by boats and railroads.  Riverboats carried it down the Ohio and Mississippi Rivers.  The Gold Rush migration carried cholera to California, where it unleashed a diarrhea rush in 1850.  Around the world, in the last 200 years, it has killed many millions.  Cholera is still alive and well in the world.

Laurie Garrett revealed a spooky side of cholera.  In water or algae, the bacteria can survive encysted, in a dormant state, for months or years.  In the harbor of Lima, Peru, a Chinese ship dumped bilge water that contained spores of a virulent form of cholera called El Tor (the bull).  People consumed raw shellfish that were contaminated with El Tor, and developed intense diarrhea.  Before El Tor arrived, Peru had stopped chlorinating drinking water, because chlorine increases the risk of cancer.  So, in 1991, El Tor eventually found its way into the water supply, and came out of faucets.  It infected 336,000 people in eleven months, and was carried to the U.S. by infected people who traveled by air.

Cholera is a disease of poor sanitation.  Its spread is encouraged by large populations, dirty water, and by high mobility (airplanes, ships, railroads, etc.).  It would not have been common among our nomadic wild ancestors.


There are several forms of typhus.  Epidemic typhus is a bacterial disease spread by lice.  It originated in temperate regions.  One to three weeks following exposure, flu-like symptoms occur.  Then, five to nine days later, a rash appears, and spreads over most of the body.  “Typhus” means confused, because many victims became delirious.  Without treatment, up to 40 percent die.

Lice transfer the bacteria from infected humans to other humans.  No other animal species is a typhus reservoir.  When a typhus-carrying louse bites, it takes some blood, and leaves behind a small gift of poop.  The bite itches, the person scratches it, and scratching pushes the bacteria through the bite opening in the skin. 

During the Great Famine, many Irish boarded boats to North America.  Joining them for the voyage were lice-ridden rats.  The boats became known as “coffin ships” because they delivered the typhus epidemic of 1847 to North America.  The immigrants were quarantined on their ships, on an island, or held in large “fever sheds.”  Tens of thousands died at sea, or in quarantine. 

Typhus thrives in crowds.  Sometimes it was called jail fever.  It was especially common during wartime.  Soldiers had little access to soap, hot water, baths, or clean clothing.  They had plenty of company from rats and bugs.  Typhus took a big toll during the Russian Revolution (1917–1923), causing 30 million cases with more than 3 million deaths.  During World War Two, scientists discovered that lice could be controlled by spraying the soldiers with DDT.  This kept them bug free for months. 

In the good old days, bathing was considered to be dangerous.  Prior to modern water systems, carrying enough water for a bath was a lot of work.  The whole family took turns using the same bath water.  In the summer, people could bathe in lakes or streams, but the arrival of autumn chilled interest in washing.  In the 1800s, even the rich got typhus, because everyone had lice. 

Typhus can be controlled by better hygiene, insecticides, and antibiotics.  No vaccines are currently available to prevent typhus.  It thrives in conditions of crowding, filth, and poverty — civilization.  It would not have been common among our nomadic wild ancestors.


Typhoid is a bacterial disease that originated in temperate regions.  It is caused by consuming food or water contaminated with fecal material.  Shellfish living in dirty water can carry the bacteria.  So can raw fruit or vegetables fertilized with humanure, or contaminated milk, cheese, or ice cream.  On one milk route in Springfield, Massachusetts, 150 consumers caught typhoid, and 25 died.  Flies can deliver typhoid to your food.  Typhoid declined when motor vehicles replaced horses, and the streets were no longer loaded with manure and flies.

Symptoms appear six to thirty days after exposure, when victims get a high fever that lasts several days, or sometimes months.  The name typhoid means “resembling typhus” because it had similar symptoms.  Not until 1837 did science discover that typhoid and typhus were different diseases.

Mary Mallon carried the typhoid pathogen, but it never made her sick.  Working as a cook, she infected at least 50 people, of whom 3 died.  Earning the nickname Typhoid Mary, she had to be forcibly quarantined for 26 years, which really pissed her off, because she wasn’t ill.

Typhoid is a popular disease in regions where dense populations dump their sewage into their drinking water supplies.  It is also encouraged by flies and filth.  Horses release 15 to 35 pounds of manure daily (7 to 16 kg).  In 1900, London streets were home to 50,000 horses.  New York had 100,000.  Dense clouds of flies feasted on the yummy crap.  The invention of the automobile actually had one benefit — by clearing the streets of horses, there was a sharp reduction in typhoid cases.

Typhoid still exists.  Worldwide there are 21 million cases annually, with 200,000 deaths.  It can be treated with antibiotics, but the bacteria have developed resistance to some of these drugs.  Since 1896, there have been typhoid vaccines, but they don’t provide lifelong immunity.  Good sanitation and chlorinated drinking water can prevent the spread. 

Typhoid thrives in conditions of crowding, filth, and poverty — civilization.  It would not have been common among our nomadic wild ancestors.

Bubonic Plague

Bubonic plague is a bacterial disease that originated in temperate regions.  It first entered history with the Plague of Justinian (541–542) which struck the Eastern Roman Empire, and initially killed about 25 million people.  Grain ships from Egypt carried infected rats to Constantinople (Istanbul), where up to 5,000 people per day died.  The epidemic returned several times over the following 200 years, and eventually killed about 50 million.  In the year 500, the estimated population of the world was between 190 and 206 million.

The second great pandemic was the Black Death, which originated in central Asia, spread through China (1331) and then hammered Europe (1347–1350), possibly killing 50 million, about one third of the people.  Periodic plague outbreaks persisted in Europe for the next 350 years.

The third great pandemic began in Yunnan China in 1855, and spread into India.  It killed 12 million people in China and India, and persisted until 1959.  In 2015, the Centers for Disease Control reported 15 cases of plague in the United States.  Around the world there are several thousand cases each year, and most are cured with antibiotics.  Today, many types of ground dwelling rodents are reservoirs of the pathogen.

Fleas acquire the pathogen by biting the rodents, and then pass it to humans with a bite.  A pustule forms, and then the lymph nodes in the armpits, groin, and/or neck swell.  There is bleeding under the skin, creating purple blotches, or buboes.  Eventually the nervous system breaks down, there is intense pain, and then death — usually on the fourth day.  Death was often preceded by violent fever, vomiting blood, convulsions, and bizarre body movement known as the danse macabre — the dance of death.

Bubonic plague thrives in conditions of crowding, filth, and poverty — civilization.  It would not have been common among our nomadic wild ancestors.  Sometimes it mutated into pneumonic plague, which could be spread to others with a sneeze, was extremely contagious, and always fatal (so outbreaks were brief).


Tuberculosis (TB) is an ancient bacterial disease that we may have acquired from ruminants.  The time, place, and way that tuberculosis originated remains the subject of controversy.  Maybe a third of humans are infected with tuberculosis, but most have no symptoms, and are not contagious because their immune systems keep it under control.  If the bacteria grow, a latent infection can become active.  It can then pass directly from person to person via coughing, sneezing, spitting, or speaking.  Symptoms include fever, frequent coughing, night sweats, weight loss, and bloody sputum. 

In the nineteenth century, as the Industrial Revolution spurred the growth of crowded cities, TB was the main cause of death in Europe and North America.  Prime victims were the malnourished who lived in damp conditions.  There was no cure.  In the twentieth century, it killed an estimated 100 million people.  It is quite contagious.  A flight attendant with tuberculosis spread it to 23 passengers during several flights.

Tuberculosis can be treated with antibiotics, but drugs are becoming less effective, because a number of tuberculosis strains are developing multiple drug resistance (MDR), a condition that is common in hospitals, prisons, and homeless shelters.  The World Health Organization reported that in 2014, there were 9.6 million cases of active tuberculosis, which resulted in 1.5 million deaths. 

Of those cases in 2014, 480,000 were MDR-TB, more than half of which occurred in India, China, and Russia.  Of these MDR cases, about 9.7 percent were XDR-TB — extensively drug resistant tuberculosis.  Recently a new variant is emerging, TDR-TB — totally drug resistant tuberculosis, which has been found in India, Iran, and Italy. 

For the last 50 years, there has been little interest in developing new first-line drugs for treating tuberculosis.  TB is a disease that mainly affects the extremely poor; folks who can’t afford to buy highly profitable wonder drugs. 

Tuberculosis thrives in conditions of crowding and poverty — civilization.  It would not have been common among our nomadic wild ancestors.


Anthrax is an ancient bacterial disease that primarily infects plant-eating mammals, especially animals that live in herds, like horses, cattle, sheep, bison, reindeer, and oxen.  Anthrax is spooky because it creates spores that can survive for centuries, even in harsh conditions.  Birds that dine on infected carcasses can move the spores to other regions.  Moving streams can carry spores downstream.  Spores have been found on every continent, including Antarctica.

Humans and other animals can become infected by inhaling spores, or eating contaminated meat.  Humans can get it by handling wool or hides.  Bacteria can enter via broken skin.  Once a dormant spore has entered the body, it can reactivate and spur an infection. 

Michaeleen Doucleff reported on an anthrax outbreak in a remote region of Siberia, where melting permafrost exposed a reindeer that died from anthrax 75 years earlier.  Old spores from the dead reindeer then led to the infection of 2,000 reindeer, dozens of people got sick, and one child died.  Because livestock are a primary source of food for humans, high mortality in the animals can lead to starvation.  When traction animals die, fields can’t be plowed.

Prior to 1900, hundreds of thousands of people died from anthrax every year.  The disease cannot be transmitted human-to-human, but when someone dies from it, the mass of bacilli in the corpse can become a source for infection.  The first effective vaccine was developed in 1881.  A second generation is available now, but has severe side effects in one percent of patients.  The disease is treatable with antibiotics.

Anthrax is encouraged by the confinement of animal herds, like in livestock operations.  Anthrax in humans is encouraged by regularly having close contact with herd animals.  It was probably less common among our nomadic wild ancestors.  Finding a bunch of dead animals may have encouraged caution.

Humans are tropical primates, and parasites thrive in a tropical climate that is close to our body temperature.  In a warm environment, it is easier for them to move between humans and other animals.  One in every four humans provides a nice home and warm meals for parasitic worms.  Parasitic diseases can cause chronic, long-term, debilitating conditions.

Our wild ancestors in tropical regions certainly had intimate relationships with parasites, but probably on a scale far less than today.  The tropics have been substantially disrupted by logging, herding, agriculture, poverty, poor sanitation, and explosive population growth.  A warming climate suggests a bright future for the parasites.

Because tropical climates don’t have cold winters, they nurture greater biodiversity, which provides prime conditions for parasitic diseases.  Parasites include protozoans, roundworms, flatworms, filarial worms, and amoeba.  We’ll take a closer look at a few parasitic diseases in the following pages. 


For humans, the deadliest creatures on Earth are not large carnivores, but mosquitoes.  Malaria is an ancient tropical disease caused by protozoans that are transmitted to humans via mosquitoes.  The disease destroys red blood cells, and an infection can last for years.  There are five varieties of malaria, caused by five different parasites.  The most deadly variety is caused by Plasmodium falciparum, which originated in birds.  Humans provide the sole reservoir for malaria parasites, and mosquitoes transfer them from the infected to the non-infected, so dense population encourages the disease.

Following exposure, the incubation period is 7 to 30 days.  Early symptoms include fever, chills, headache, sweats, fatigue, nausea, and vomiting.  Complications can include brain infection, kidney failure, liver problems, pulmonary edema, coma, and death.  Some believe that malaria has killed more people than any other disease.

Mark Nathan Cohen noted that malaria and yellow fever were originally treetop diseases that infected non-human primates.  As humans cleared forests for agriculture, they became vulnerable to these diseases.  Malaria was rare among nomadic people, but common in farming communities, especially where rice was grown in flooded paddies (mosquito incubators).

Malaria and yellow fever were transferred to the Americas via the slave trade.  In 1864, George Perkins Marsh noted that malaria followed deforestation.  In Virginia and the Carolinas, malaria was rare in forested areas, but common in cleared places, especially near the flooded rice paddies in South Carolina and Georgia.  He wrote, “The cultivation of rice is so prejudicial to health everywhere that nothing but the necessities of a dense population can justify the sacrifice of life it costs in countries where it is pursued.”

John Perlin described how the ancient Greeks cleared forests to create wheat fields.  Deforestation led to severe erosion that filled deep harbors with soil, creating malarial marshes.  Malaria was so bad that port cities had to be abandoned.

The ancient Romans repeated the same mistake.  For centuries, wealthy Romans spent their summers at higher elevations to avoid malaria.  Geoffrey Marks noted that in the eleventh century, the Germans who conquered Rome declared it to be uninhabitable, and abandoned it.  For centuries, malaria made Rome almost uninhabitable in the summers, until Mussolini drained the Pontine Marshes in the 1930s.

Today, a billion people live in malaria country.  Mosquitoes are developing resistance to insecticides, and the malarial parasites are developing resistance to every antimalarial drug.  No vaccines are available.  Malaria is untreatable in some regions.  The World Health Organization (WHO) estimated that in 2010 there were 219 million cases of malaria (mostly in Africa), resulting in an estimated 660,000 deaths.  WHO models indicate that a global temperature rise of 2 to 3°C will put 3 to 5 percent more people at risk of malaria (several hundred million).

Margaret Humphreys noted that three types of malaria were imported to the U.S. by immigrants from Europe, the Mediterranean basin, and African slaves.  It spread as far north as Tennessee and North Carolina.  Slaves and mosquitoes mingled together in flooded rice fields in South Carolina, and then the mosquitoes infected whites.  By the 1680s, whites were getting hit hard, especially the young.  Many families fled north during the summer months.


Schistosomiasis (bilharzia) is the second most common parasitic disease, after malaria.  It is caused by parasitic worms that live in freshwater snails.  The worms emerge from the snails and burrow through the skin of humans standing in the water, often in irrigated fields.  These worms can live in your body for 40 years.  As their eggs move through your organs, they cause bleeding.  Infection sometimes results in bladder cancer, and liver disease.  The parasite returns to the water in the feces of victims.  It’s nearly impossible to eliminate the snails, but medications can eliminate worm infestations in the body.  Where schistosomiasis is common, many die young. 

Sleeping Sickness

Sleeping sickness (trypanosomiasis) is a tropical disease that originated in Africa.  It is caused by a family of protozoa named Trypanosoma brucei.  Originally, sleeping sickness was transferred from wild antelopes to humans via tsetse flies.  The protozoa did not sicken the antelope.  Amazingly, the tsetse can drink its own weight in blood in seconds.

For a long while, humans were little affected by sleeping sickness, because they didn’t live in close contact with wild animals.  But, once upon a time, the herders of domesticated cattle got really tired of living in warm and green ecosystems, because they were hotbeds of malaria.  So, to escape from the mosquito hordes, they packed up and moved to a dryer region — tsetse country. 

In tsetse country, the native African wild mammals were resistant to the disease, but livestock brought in from elsewhere were not.  Cattle and herders were infected with sleeping sickness, and the cattle were hit extremely hard.  Slave traders carried the sleeping sickness protozoa to uninfected regions. 

The disease messes up the mind and body in many ways, but the most obvious symptom is that victims sleep a lot, and can be very difficult to awaken.  Left untreated, all victims fall into a coma and die.  There are two forms of sleeping sickness, caused by two different types of protozoa.  More than 98 percent of the cases are caused by the weaker one, which can take three years to kill the victim.  The stronger form is more virulent, killing the victim within months.

In 1859, a sleeping sickness epidemic around Lake Chad was so severe that the town of Digazore, Nigeria was deserted for 50 years.  Between 1896 and 1906, sleeping sickness killed 500,000 in the Congo.  Between 1898 and 1908, it killed 200,000 of the 300,000 living along the northeast shores of Lake Victoria in Uganda.  In 1952, Charles Winslow wrote that most of Tanganyika was uninhabitable because of the large tsetse fly belt.

In numerous tsetse hotbeds, trying to graze cattle was not worth the effort, because too many died.  People had to get their protein via foods from elsewhere.  On the plus side, the flies protected the indigenous wildlife.  William McNeill wrote, “It is mainly because sleeping sickness was and remains so devastating to human populations that the ungulate herds of the African savanna have survived to the present.”

Insecticides cannot eliminate the tsetse flies because they inhabit large regions.  Eliminating the wildlife that are hosts to the parasites is not an option.  Health experts expect that a warming climate is likely to open up new frontiers for tsetse flies.  Currently, they are only in Africa. 

River Blindness

River blindness (onchocerciasis) is caused by an infestation of filarial worms that colonize the eyeballs.  In some areas of Africa, up to 30 percent of adults are blind.  Humans acquire the parasites via bites from black flies, which breed in warm rivers.  The flies are hard to exterminate, because some can travel up to 400 miles (640 km) in one day.


Lymphatic filariasis is commonly known as elephantiasis.  When humans donate blood to mosquitoes and black flies, the insects transmit roundworms to the humans.  Infection usually occurs in childhood, and eventually results in damage to the lymphatic system.  Untreated, the legs and scrotum of the victims can swell to enormous size.  Drug therapy and surgery can treat worm infestations.  Intensive insecticide spraying can reduce the flies and mosquitoes.

Chagas’ Disease

Chagas’ disease is caused by parasite named Trypanosoma cruzi.  This protozoa is usually spread by kissing bugs, and it has a reservoir in wild and domestic animals.  The bugs first bite an infected person, then bite a healthy person, and dump some feces by the bite.  Scratching the bite rubs the feces into the wound, and the parasites move into their new home, where they might reside for decades.  Some victims experience cardiac or intestinal complications.  Chagas’ disease is common in Mexico, Central America, and South America.  Seven to eight million have the disease, and it causes 12,500 deaths per year. 

Viruses are not living organisms.  They are segments of protein-coated genetic material (DNA or RNA) that can infect the living cells of plants, animals, or bacteria.  When infected cells reproduce, the offspring carry the virus.  There are millions of types of viruses.

They can be transmitted by insects, coughing and sneezing, feces, body fluids, person-to-person contact, or via eating or drinking.  Some viruses can infect the cells of a few different species, and others can infect many.

Yellow Fever

Yellow fever is a tropical disease caused by a mosquito-borne virus.  The virus originated in forest primates, who remain the primary hosts.  It is a hemorrhagic fever.  About 15 percent of victims advance to the second phase of the disease, in which they bleed from the mouth and eyes, and vomit blood.  Without treatment, up to 20 percent of victims die.  This can increase to 50 percent in severe epidemics.

The Aedes aegypti species of mosquitoes carries the yellow fever virus.  A tropical village could go decades without a case of yellow fever, because the mosquitoes stayed in the jungle, feeding on marmosets and monkeys.  Cutting a stand of trees could spark an epidemic, by bringing mosquitoes closer to the ground, to breed in pools of water on the stumps. 

Aedes aegypti can’t survive in a chilly climate.  They have migrated out of Africa, and now enjoy life in tropical and subtropical regions around the world.  They are thrilled to hear news about global warming, and they urge all humans to increase their carbon-emitting habits, please!  Drive like crazy!  Fly everywhere!  Recently, they have been found as far north as Sacramento and New York City.  Yellow fever was far less common in the days before our ancestors became forest molesters, farmers, and city folks. 

There is no cure for yellow fever, but a preventive vaccine was developed in 1938.  Over time many Africans have developed immunity to it, and can carry the virus without getting sick.  Non-Africans have not been so lucky; they die like flies when the virus comes to visit.  Anyway, when the good white Christians brought African slaves to the New World, yellow fever came with them.  Neither Native Americans nor white colonists had any immunity at all.  A virgin land epidemic exploded. 

Geoffrey Marks reported that there were epidemics in the U.S. northeast from 1686 to 1832, but it was far more prevalent in the south.  For example, epidemics hit Charleston, South Carolina in 1699, 1706, 1711, 1728, 1732, 1790, 1791, 1792, 1795, 1798, and 1799.  In 1820, one-third of the people in Savannah, Georgia died.  Forest clearing and numerous rice paddies provided abundant habitat for mosquitoes.  Today, vaccines keep the disease under control in many regions.


Influenza is a viral disease that originated in temperate regions.  It can be highly contagious, and some variants can be highly lethal.  It often mutates into new variants, and many experts are concerned that a new deadly influenza pandemic is quite likely, at some point in time.

It’s odd that many people have heard about the Black Death pandemic of 650 years ago, but far fewer know about the global influenza pandemic of 1918.  We prefer to forget it.  At a time when world population was about 1.7 billion, the flu infected 500 million, and 50 to 100 million died.  It spread around the world in just two months, in an era before commercial air travel.  Doctors were helpless to treat it.  Some feared the end of civilization.

After a few days of aches and pains, victims would start bleeding from their ears, nose, or eyes.  Their lungs filled with blood, and their skin turned purple.  Some called it the Purple Death.  Folks that appeared healthy at breakfast were dead by evening.  Oddly, mortality was highest among healthy adults between the ages of 20 to 40.  Some believe that the flu didn’t kill them.  They died because their healthy immune systems freaked out, flooded their bodies with proteins that caused inflammation.  Children and old folks had less robust immune systems, and survived in greater numbers. 

Richard Collier wrote an unforgettable play-by-play description of the 1918 pandemic, taken from news accounts of the day.  Quarantines didn’t work because infected people can appear healthy for a few days.  In 1918, ships known to be carrying infected people were allowed to enter ports.  The SS Niagara took infected passengers to New Zealand, resulting in 6,680 deaths.  The Canadian Pacific railroad carried the flu across the continent, infecting each city where the train stopped.  Some victims went into deep comas, with no pulse or breathing — and then revived in their closed coffin.

Dr. Michael Greger wrote that wild ducks and influenza viruses peacefully lived together for 100 million years.  If humans had never domesticated ducks, influenza might be unknown today.  Unfortunately, ducks were domesticated 4,500 years ago in China, moved onto rice paddies, where they were close to chickens, pigs, and humans that were not immune to the viruses.  Because China raises 13 billion chickens, 2 billion waterfowl, and 500 million hogs in close contact with humans and other species, it provides perfect conditions for encouraging the mutation of viruses, and their spread to other species.

When a highly lethal, highly contagious mutant emerges, wild migratory birds can carry it to faraway regions, like North America, via Alaska.  They poop in the water, and other species acquire the viruses when drinking.  It’s vital that we change the way we raise animals, but there is little interest.  Especially bad are Chinese fish farms where hog, chicken, and human wastes are used as feed.

When the next highly contagious, highly lethal variant appears, existing vaccines may not prevent it.  Flu viruses can rapidly mutate, creating a moving target for vaccine makers.  Creating a new vaccine can take six to eight months.  Then it has to be mass produced and distributed.  By then, the pandemic will be over. 

Influenza is the result of animal domestication.  Its spread is encouraged by dense populations, high mobility, and living with others indoors.  It would not have been common among our nomadic wild ancestors.  The last words of one 1918 flu victim in Guatemala were, “We die of the blessings of civilization.”


Smallpox is a viral disease that originated in temperate regions.  It is highly contagious and highly lethal, especially in children under two years old.  It does not spare the wealthy.  Smallpox is transmitted via face-to-face contact, exposure to infected body fluids, or by touching contaminated items like clothing or bedding.  Following exposure, the incubation period is 10 to 14 days, which allowed infected people to travel to distant villages before discovering they were sick.

Symptoms include fever, headache, fatigue, back pain, and vomiting.  Red spots then spread over the body, then turn into small blisters, which turn into scabs, and then leave behind deep pitted scars.  Most victims over ten years old survive, but some varieties of smallpox are almost always fatal.  Once infected, there is no cure, but the symptoms can be treated. 

There is evidence that smallpox existed before 1000 B.C. in Egypt, India, and China.  It may have appeared much earlier.  Many believe that the virus originated in cows, but others suspect camels.  Travelers from Eurasia carried the virus to the Americas and Australia, where natives had zero immunity and suffered fatality rates up to 90 percent.  In the twentieth century, an estimated 300 to 500 million people died from smallpox.

No other animal provides a reservoir for the smallpox virus.  Only humans carried it.  Because of this, science was able to eradicate the disease via a successful vaccination program.  Smallpox was eradicated in the U.S. in 1972, and the last case occurred in Somalia in 1977. 

Smallpox almost certainly was a consequence of the animal domestication.  Experts do not agree on the source, but most say camels, and some say cattle.  It would not have been common among our nomadic wild ancestors.  They probably never experienced it.


Rinderpest is a viral disease that affects ruminants — hoofed animals like cattle, goats, sheep, antelopes, deer, and giraffes.  It is the most virulent of all livestock diseases.  Because livestock are a primary source of food for humans, high mortality in the animals can lead to starvation in humans.  When beasts of burden die, fields can’t be plowed, and carts do not move.

Rinderpest is highly contagious and has high mortality rates.  When an animal is infected, it takes 3 to 15 days for symptoms to appear.  They include high fever, diarrhea, and skin lesions.  Death follows in 6 to 12 days.  All of a sick animal’s fluids are contagious, including tears, urine, saliva, snot, and excrement.

Andrew Rimas noted that the virus apparently originated in East Asia.  Mongols carried it west to the Ukraine in 1240, and it eventually spread as far as Scotland.  In 1865, a rinderpest epidemic in Europe killed up to 200 million cattle.  In 1885, infected cattle were shipped by Italian soldiers to Eritrea, and by 1890, 92 percent of the cattle in East Africa were dead.  It took a similar toll on wild ruminants, like buffalo, bison, oryx, elands, and the greater kudu.  The Maasai are a tribe of cattle herders, and two-thirds of them perished from starvation.  Large feline predators starved.  In the absence of large herbivores, trees began to spread into the savannah.

The rinderpest virus likely originated in wild herd animals, and it is likely more than 5,000 years old.  It’s closely related to the measles virus, and is probably older.  Human populations were not large enough to maintain endemic measles until a thousand years ago.  Humans can’t get rinderpest, and other animals can’t get measles.  In 2011, rinderpest went extinct in the wild, because of a successful vaccination program.

Rinderpest thrived in dense populations of confined domesticated livestock.  Our nomadic wild ancestors probably did not observe often it among wild ruminants, if ever.


Measles is a highly infectious viral disease that originated in temperate regions.  It spreads from person to person via coughs and sneezes.  Ten to twelve days after exposure, symptoms appear, including inflamed eyes, fever, cough, and runny nose.  Three to five days after the start of symptoms, a red rash spreads over the body, beginning at the face.  Complications include pneumonia, brain inflammation, blindness, and diarrhea. 

Most of those who survive a measles infection will be immune for the rest of their lives.  Therefore, measles needs a continuous supply of victims who are not immune, namely young children.  Of those who are not immune, about ninety percent will become infected when exposed to the virus. 

Humans are the sole reservoir for measles.  It cannot persist in populations of less than 250,000 to 500,000 people, it will die out.  Measles was first noted in written records in the tenth century, as European cities grew to densities sufficient to provide a good home for the virus.

Dr. E. Fuller Torrey notes, “It has been estimated that between 1840 and 1990, measles killed about 200 million people worldwide.”  A measles vaccine was introduced in 1963.  Once upon a time, the World Health Organization hoped to eliminate measles by 2020.

Measles thrives in dense populations and poverty.  It would not have been common among our nomadic wild ancestors.


New types of viral diseases are now appearing, as humans move deeper into remote areas of the tropics.  Loggers are destroying forests, and bush meat hunters are selling a variety of wild primates for food.  Because humans are Old World primates, we are more vulnerable to the diseases of other Old World primates, like Ebola, Marburg, and AIDS.  We are less closely related to the monkeys of the Americas, so we are not so susceptible to their diseases.

Viruses are notorious for having a tendency to mutate, like the influenza virus.  Wild monkeys are susceptible to a highly lethal airborne virus that gives them cancer.  The virus has not mutated into a form that humans are vulnerable to — yet.  Ebola and Marburg are highly lethal, but the viruses that cause them have not succeeded in permanently established themselves in human populations — yet.  Folks who work in labs with monkeys are getting monkey diseases.  Idiots have experimented with transplanting baboon organs into humans.

The human immunodeficiency virus (HIV) is contagious.  When it is untreated, it can lead to acquired immunodeficiency syndrome (AIDS), a disease that has killed about 40 million.  HIV is probably a mutation of the simian immunodeficiency virus (SIV) which is carried harmlessly by chimps.  The bushmeat business now operates at an industrial scale, and bushmeat vendors are often exposed to the blood of SIV infected chimps.  The first well-documented case of AIDS was in 1959 in the Congo.  By the late 1970s, HIV was in the U.S.  It spread rapidly among the gay community.  HIV researchers at the National Institutes of Health had to keep redefining the meaning of “multiple sex partners.”  It was 20 partners per year in 1975, 50 in 1976, 100 in 1978, and 500 in 1980.  One fun-loving lad claimed 3,000.

Ebola hemorrhagic fever is a viral disease of humans and other primates.  It is active in tropical Africa, and outbreaks tend to occur when heavy rains follow a long dry spell.  In advanced stages of the infection, victims bleed internally and externally.  The virus is transmitted via skin-to-skin contact, and exposure to patient’s body fluids and excretions.  Usually, mortality is 50 percent, but can run as high as 90 percent.  Fruit bats are the likely reservoir of the virus, which does not make them sick.  A recent epidemic in West Africa ran from 2013 to 2016, with 28,657 cases and 11,325 deaths.

Marburg hemorrhagic fever is a deadly viral disease that infects humans and non-human primates.  It is active in the arid woodlands of equatorial Africa, and fruit bats are the reservoir for the virus.  It typically infects people who visit bat-infested caves, or work in mines.  It is transmitted via skin-to-skin contact, and exposure to patient’s body fluids and excretions.  Its symptoms are the same as Ebola.  Victims die from the failure of multiple organs, not hemorrhage.  A severe outbreak in Angola in 2004–2005 had a mortality rate of 90 percent.  The U.S. Food and Drug Administration has approved no vaccines for Marburg.

SARS (severe acute respiratory syndrome) is a viral disease first identified in 2003.  Symptoms appear two to ten days after contact, with fever and respiratory problems.  Severe cases can result in respiratory failure.  In 2003, nine percent of all victims died.  For those older than 50, almost half died.  Scientists believe that it was passed to humans via palm civets, animals sold for human consumption in Guangdong, China.  It has also been found in raccoon dogs, ferret badgers, and domestic cats.  The natural reservoir for the virus may be bats, which carry it harmlessly.  The virus is apparently transferred when different species are in close contact, as they are in Chinese markets — conditions far different from normal life in the wild.

Lassa hemorrhagic fever is a viral disease of humans and non-human primates.  It is endemic in western Africa, where it infects 100,000 to 300,000 each year, and kills about 5,000.  The reservoir for the virus is a type of rat that commonly colonizes human settlements, and feeds on stored food.  Infected rats excrete the virus in their urine and feces.  Humans are infected via inhalation, open wounds, or ingestion of contaminated foods.  Most infections are mild and not diagnosed, but twenty percent can get serious.  The U.S. Food and Drug Administration has approved no vaccines for the Lassa virus. 

Coronavirus disease (COVID-19) is a viral disease that triggered a global pandemic in early 2020.  It has the potential to become catastrophic.  The future has yet to be written.


Wikipedia lists some examples of degenerative diseases — cancer, heart disease, diabetes, macular degeneration, Alzheimer’s, Lou Gehrig’s disease, chronic obstructive pulmonary disease (COPD), inflammatory bowel disease, multiple sclerosis, osteoporosis, Parkinson’s disease, rheumatoid arthritis, muscular dystrophy, and many more.

I’m not going to say much about these diseases, because they are all around us, fully out in the open, and I’ve already said enough to express my views about health among the wild and non-wild.  I’m wary about sharing long term health trend statistics, because they are probably inaccurate and misleading.

In 2007, Clive Ponting wrote that one in three Americans contracts cancer, compared with one in 27 in 1900.  Many folks who died in 1900, in big cities and rural farmhouses, were not included in regional or national records of cancer deaths.  Not all regions kept records.  Back in the simpler days of paper and fountain pen technology, if an elderly person did not die violently, the death was likely attributed to “natural causes.”  Nothing to see here.  Have a nice day!

So, I’m going to share one source I trust, and call it a day.  Over many years, journalist John Gunther travelled 40,000 miles in Africa, and visited most of the 44 countries or political subdivisions, including 105 towns.  He interviewed many experts and officials, and wrote a 950 page book, which was published in 1953.

When he was in the Sahara region, he wrote: “At the El GolĂ©a hospital the resident doctor told us that, in ten years, he has never had a case of appendicitis in a native, or seen a cancer.  Elsewhere in Africa we subsequently found doctors who reported this same extraordinary thing.”  In Bantu country, he wrote: “Cancer is almost unknown among the Africans, and diseases of filth, like cholera and plague, are uncommon.”  In French Equatorial Africa, he wrote: “Dr. Albert Schweitzer has never seen appendicitis in an African; and cancer is virtually unknown.”

Saturday, May 2, 2020

Wild Free and Happy Sample 38

[Note: This is the thirty-eighth sample from my rough draft of a far from finished new book, Wild, Free, & Happy.  I don’t plan on reviewing more books for a while.  My blog is home to reviews of 203 books, and you are very welcome to explore them.  The Search field on the right side will find words in the full contents of all rants and reviews, if you are interested in specific authors, titles, or subjects.] 

Domestication and Disease

William McNeill wrote a fascinating history of disease.  It’s sprinkled with some sparkles of outside-the-box ideas.  First, some basics.  In the family of life, parasites are the eaters, and hosts are the eaten.  You are host to billions of tiny microparasites (bacteria, viruses, and multi-celled critters) that live within your body, from infancy to the finish line.  Usually, they are good guys.  They promote your survival, while enjoying a free lunch on the nutrients they find within you.  There are also large bodied macroparasites, like lions, tigers, sharks, and humans.

Not all microparasites are our buddies.  Some can cause disease.  They can trigger infections that result in mild illness, or intense infections that can kill you.  Sometimes their attempts at invasion are blocked by a robust counterattack from your immune system.  Hosts can sometimes serve as carriers of disease-causing parasites, helping them hitch free rides to uninfected new hosts.  Carriers sometimes don’t display symptoms, or feel noticeably sick.

Hominins evolved in Mother Africa.  Tropical rainforests are the ecosystems having the highest biodiversity of plants, animals, and parasites.  Over the course of many thousands of years, Big Mama Nature nurtured the coevolution of parasites and hosts so that the balance between eaters and eaten was generally stable over the eons.  This discouraged single species of renegade plants or animals from overturning the ecological boat.  Everyone in the family of life, from microbes to crocodiles, simply played their assigned role.  In the never-ending sacred dance, we all feed each other, and it is right and good.

Because of this general equilibrium, lions and herds of large herbivores could share the same grasslands for century after century.  The predator’s objective was not to eliminate as many prey as possible.  Their job was to have a nice time participating in the sacred dance.  Unfortunately, the equilibrium got more and more wobbly as humans shifted from the slow lane of genetic evolution, and swerved into the dangerous express lane of cultural evolution (weapons, fire, language, etc.). 

Epidemics of highly contagious cleverness fever enabled some cultures to live way too fast and hard, causing serious damage to their ecosystems.  This process was similar to how disease-causing microparasites sicken or kill their hosts.  McNeill concluded that civilization could be seen as a macroparasite that is ravaging the family of life — like “an acute epidemic disease.”  He wrote in 1976.  Today, we would call it a devastating global pandemic.

Before the plague of cleverness fever, Big Mama Nature lovingly kept our ancestors humble.  In the good old days, the notion that we were the glorious Crown of Creation was unknown, because it was idiotic.  Tsetse flies laugh out loud at the myth of human supremacy.  When an anthropologist asked some wild folks how humans were different from other animals, they were baffled.  There is no difference.  What a stupid question!  A Kuyukon elder once told Richard Nelson: “Every animal knows way more than you do.”

Before cleverness fever and agriculture, we didn’t suffer from devastating population explosions, because our bloodthirsty carnivorous macroparasite brothers and sisters regularly invited us to lunch.  Over time, disease-causing microparasites came to assume a larger role in preserving the equilibrium.  Both teams weeded out the weak, elderly, and unlucky.  This was their sacred mission — a lovely sustainable circle dance, not a horror show blitzkrieg.

The high biodiversity of tropical rainforests enabled a huge variety of parasites to feast on a huge variety of hosts.  McNeill noted that monkeys and tree-dwelling apes are hosts to 15 to 20 species of malaria (humans just 4).  Wild primates are also hosts for legions of mites, fleas, ticks, flies, worms, protozoa, fungi, bacteria, and more than 150 insect-borne viruses. 

He suspected that this daunting parasite heaven was probably a significant reason why civilization emerged more slowly in Africa.  Civilization is about growth and control, not equilibrium.  The incredible biodiversity of rainforests creates a powerful communal life force that regularly frustrates the efforts of clever tropical primates to become the domineering King of the Jungle.

Snow Country

According to McNeill, some super-important events in the human saga included our transition from tree dwellers to ground dwellers, the domestication of fire, and the colonization of snow country.  The climate in snow country was temperate, not tropical.  While warm moist tropical rainforests were ideal habitat for a staggering number of species, snow country was less complex.  Organisms that could not tolerate freezing temperatures, or low humidity, were absent from the playground.

And so, the brave pioneers wandered out of their tropical homeland, and into a gentler cooler world.  Snow country was home to far fewer disease-causing parasites, none of which specialized in infecting primate hosts.  Snow country was also home to vast numbers of large game animals that had never seen humans before, and had no instinctive fear of them. 

Large game was the pioneer’s primary energy source, and it was eventually depleted by overhunting, over the course of thousands of years.  A band could dine on a mammoth for a week, or they could invest far more time and effort killing a ton of bunnies.  As the pioneers expanded into new regions, megafauna extinctions followed in their wake.  Eventually, folks had to make a painful choice — labor-intense food production (agriculture) or mindful conservation via voluntary self-restraint (family planning).  Because they were basically ordinary animals, they lacked the mental bandwidth to automatically deal with this complicated predicament.

Today, our primary energy source is fossil energy (ancient sequestered carbon), which we are depleting at an insane rate, over the course of mere decades, with complete disregard for how this will impact our beloved kiddies.  (Sorry!)  We’re burning it up like crazy, to support the survival of way too many people, who live like there’s no tomorrow, for no good reason.  One estimate is that, of all the carbon emitted during the entire human saga, more than half of it has been emitted just since 1990 — a single generation (my generation).  (Blush!)

Anyway, to human supremacists, the escape from a tropical parasite heaven would seem like a wonderful triumph.  Pioneers were now “liberated” from the constant threat of many killer diseases.  We’re so smart!  Their impulsive joyride of adolescent cleverness inspired them to hippity-hop blindfolded into an ecological minefield.  Oh-oh!  The tropical diseases they had escaped from had actually been their allies.  Their parasite partners, both macro- and micro-, had worked hard to prevent population outbursts, which therefore discouraged overhunting, which therefore discouraged starvation.  Imagine that!  In the good old days, we didn’t need wisdom, foresight, or troublemaking smarty pants.  All we had to do was dance.

Deep ecology thinkers, on the other hand, would be likely to perceive the invasion of snow country as an extremely dangerous experiment (i.e., stoopid).  See, Big Mama Nature was blessed with deep wisdom, not juvenile cleverness.  Under her guidance, genetic evolution had slowly and carefully fine-tuned us for survival in tropical regions.  Our ancestors got sun protection from their beautiful brown skin and curly hair, and increased heat tolerance from their sleek furless exterior, combined with a high performance collection of juicy sweat glands. 

Earlier in this word dance, I talked about the snow monkeys of Japan, who faithfully obeyed every commandment of genetic evolution, and allowed Big Mama to very slowly and carefully provide them with luxurious warm coats.  They were so lucky to avoid the curse of cleverness.  As a result, they had no need to domesticate fire, make hunting weapons and clothing, destroy the topsoil, destabilize the climate, trigger pandemics, and so on. 

The human pioneers who invaded snow country, on the other hand, violated every commandment.  Rather than patiently evolving for many thousands of years, the smarty pants impulsively took a blind leap into the unknown — sink or swim, let’s go!  Whee!  They bet everything on cleverness, and managed to survive, but their winnings were tiny, compared to the enormous cost of the countless unintended consequences they conjured into existence — the wobbly, wheezing, delirious, jam-packed world outside your window, for example.

Herd Diseases

As mentioned earlier, the temperate grasslands of Eurasia were home to lots of wild sheep, goats, cattle, and horses — herd animals that were suitable for domestication.  They eventually became vital assets for metastasizing empires and civilizations.  Over time, herds of enslaved livestock accumulated wherever green grass was abundant. 

As mentioned earlier, monocultures of crop plants are irresistibly attractive to legions of ambitious parasites seeking free lunches, like potatoes attract blight fungus.  Similarly, concentrated mobs of herd animals are also powerful magnets for swarms of hungry uninvited parasites.  Uninvited?  Methinks monocultures of domesticated plants and animals are essentially impossible-to-ignore invitations to parasites.  Today, a sprawling herd of seven-point-something billion tropical primates has a “Kick Me” sign taped to its back, and billions of giggling disease-causing parasites are eager to obey.  Monocultures are embarrassing abnormalities that ecosystems must resolve.

McNeill noted that humans did acquire some diseases via wild animals — bubonic plague (rodents), rabies (bats), yellow fever (monkeys), and so on.  But most of the classic infectious diseases of civilization were acquired from close contact with herd animals, primarily domesticated critters.  Once acquired, and over time, some of these parasites became capable of direct person-to-person transmission.  These included tuberculosis, measles, smallpox, chicken pox, whooping cough, mumps, and influenza.  By and by, human health in the Old World took a sharp turn for the worse following the domestication of herd animals.  In the Bible, “plague” appears 128 times, and “pestilence” 50 times.

James Scott noted that humans share a large number of illnesses with farm yard animals, including poultry (26), rats and mice (32), horses (35), pigs (42), sheep and goats (46), cattle (50), and dogs (65).  When different species live crowded together in close proximity to a herd of humans, trouble is sure to follow.

This was not the case in Australia, where zero plants or animals were domesticated.  Bill Gammage wrote about the Aborigines.  Over the course of many thousands of years, they developed time-proven strategies for living well in a challenging land.  They built no cities, but some groups inhabited simple villages during the months when local food resources were seasonally abundant.  Consequently, no serious diseases were native to Australia.

The story was similar in the New World, where only two species of herd animals were domesticated, alpacas and llamas.  They did not live in enormous herds in any of the vast American grasslands.  Their range was limited to remote regions of the Andes Mountains in western South America.  Neither has been associated with the emergence of any epidemic disease.

Why were just two large herbivores domesticated in the New World?  McNeill pointed out that around 12,000 years ago, the megafauna species in the Americas were sharply thinned by extinction spasms.  Some of the large herbivore species that vanished may have been suitable for domestication, but they blinked out.  Modern science has not yet figured out how to domesticate extinct animals. 

On the plus side, no powerful epidemic diseases were native to the Americas.  On the downside, Native Americans had zero immunity to the nasty microparasites that crossed the Atlantic in the 1500s, and eventually killed maybe 90 percent of them.  The spectacularly deadly Old World disease pool crashed head-on into maybe 100 million helpless sitting ducks.

Disease pool?  Long ago in the Old World, different diseases emerged in different regions, as local parasites learned how to infect local hosts (sort of like how scattered tribes developed unique languages).  In the beginning, these local diseases resided in limited territories.  Over time, expanding trade networks and civilizations linked more and more communities and regions together.  So, homegrown diseases had more opportunities to hit the road, and infect defenseless populations elsewhere.  At the same time, it became easier for exotic diseases from elsewhere to visit your neighborhood, and spur a surge in coffin sales.

Communities along the entire coastline of the Mediterranean Sea were extensively interconnected by regular commerce.  Because of these trade webs, the population of the Mediterranean Basin shared the same mob of diseases.  McNeill called the residents of this region a disease pool.  India’s disease pool hosted a different assortment of microparasites.  China’s pool had yet another collection.  He jabbered at great length about how the different Old World disease pools expanded and blended together over the centuries.  By 1500, Eurasia was essentially home to one unified disease pool, a powerful hurricane of pathogens.  It then leaped across the Atlantic and absorbed the New World into its pool.

Alfred Crosby described the diseases present in the Americas prior to colonization.  They included “pinta, yaws, venereal syphilis, hepatitis, encephalitis, polio, some varieties of tuberculosis, and intestinal parasites” (syphilis and tuberculosis are controversial).  McNeill noted that the native traditions about precolonial times did not mention epidemics.  Aztec history described just three disasters (in maybe 780, 1320, and 1454) that caused many deaths, but they seem to have been the result of crop failure or famine.  In the early days of colonization, elderly natives told Spaniards that they had no memory of disease prior to conquest.

Obviously, the European diseases overwhelmed the Native Americans.  Today, folks with white faces are now the majority in many regions of North and South America.  This is far less true in Africa.  When whites colonized the Americas, the natives had no immunity to their diseases, and they were massively swept away.  When whites tried to colonize Africa, many Africans were swept away, but they were not alone.  Mother Africa was not amused by the disruptive infestation of spooky looking albino-like primates from outer space, and she punched back very hard, using her deadly arsenal of tropical diseases, which white folks had little immunity to.

Michael Williams said that she fetched her mojo bundle and mercilessly paddled white asses with dysentery, yellow fever, typhoid, and especially malaria.  The mortality rate (deaths per thousand) for white folks in Africa was ten times higher than the rate for those who wisely remained back home in Europe.  Africa was “the white man’s grave.”  But the whites brought firearms, and before long began carrying away everything of value they could get their hands on (gold, diamonds, ivory, slaves, etc.).  They were really into wealth and status.

Epidemic vs. Endemic Diseases

Alfred Crosby noted that when Siberian hunters first discovered America, they entered a continent that was home to no humans, or any of our close relatives (chimps, gorillas, etc.), so there was no existing pool of ape-loving pathogens ready to welcome them, infect them, and compost them.  Nathan Wolfe added another point.  Humans and Old World monkeys are more closely related genetically, because their ancestors have been hanging out together for 5 million years.  New World monkeys are far less closely related to us, because our relationship is just 15,000 years old.

Also, when America was discovered 15,000 years ago, there were no domesticated animals in the entire world, except for dogs.  Because of this, James Scott believes that epidemic diseases probably didn’t exist anywhere at that time.  Most diseases probably emerged in the last five to ten thousand years, as an unintended consequence of domestication, civilization, and other variants of self-defeating cleverness. 

Epidemic refers to diseases like smallpox, which hopped off a ship in North America, rapidly infected a population that had no immunity to it, and killed millions.  It was an unfamiliar pathogen that infected a defenseless population for the first time.  Likewise, when measles arrived in America, it also exploded with deadly epidemic force. 

Back in Europe, measles had over time softened into a less lethal endemic disease, because it remained in the population as a chronic infection for many years.  What we call “childhood diseases” are endemic — measles, mumps, whooping cough, etc.  Endemic diseases can reside in cities and in locations near them, but not in small nomadic groups of wild people.  The host population must be large enough to preserve the pathogen, by allowing it to pass from one generation to the next.

Prior to modern high mobility, endemic measles required a population of 250,000 to 500,000 to survive in a community.  Today, as many millions travel everywhere all the time, it’s easy to get infected in locations far from Measles City.  The shift to agriculture enabled the existence of dense populations.  Before agriculture, endemic measles could not exist anywhere.  Epidemic measles likely originated in cattle.

Crowd vs. Tropical Diseases

Nathan Wolfe and team analyzed the origin of 25 major infectious diseases that sicken humans.  They sorted them into two categories: 10 tropical diseases, and 15 they called temperate.  “Temperate” is not a precise description, because temperate diseases are also free to infect folks in the tropics.  Infectious diseases are complicated rascals that don’t neatly fit into tidy categories.  Wolfe summed it up like this: “The sources of tropical diseases tend to be wild primates.  The sources of temperate diseases tend to be domestic animals.”

Measles originated in cattle, but cattle no longer function as a reservoir for the measles virus.  So, cowgirls don’t catch measles from cows.  The virus is preserved entirely in the human herd, so healthy cowgirls catch measles from infected people.  This direct person-to-person transmission is a common characteristic of the diseases of civilization — crowd diseases.  Crowd diseases include diphtheria, influenza, measles, mumps, pertussis, plague, smallpox, typhoid, and typhus.  Two crowd diseases also have animal reservoirs, plague (rodents) and influenza (wild birds).

Tropical diseases include Chagas’ disease, dengue fever, yellow fever, sleeping sickness, and malaria.  These are transmitted by insects.  None of them require a significant population of hosts.  Even small bands of nomadic hunter-gatherers are vulnerable to them.  All of them originated in the Old World, except for Chagas’ disease, a New World parasite.

Tropical diseases originated in tropical regions, but some were free to visit temperate places.  Geoffrey Marks noted that yellow fever arrived in New York by 1686, and it had a good time.  It returned in 1702, 1743, 1745, and 1748.  During Philadelphia’s yellow fever epidemic of 1793, terrified citizens either fled town, or stayed off the streets and shut themselves indoors.  They obsessively cleaned their dwellings.  When they went outdoors, they held handkerchiefs or sponges soaked with vinegar or camphor near their noses.  Burials had no ceremonies; no friends or relatives appeared.  People quit shaking hands, and were affronted when a hand was offered.  Four thousand died between August and October. 

Dirty Diseases

Like animal domestication, plant domestication also had a devastating impact on human health.  Evolution optimized tropical primates for a life of foraging and scavenging in a warm climate, while living in small, widely scattered, nomadic bands.  Much later, when some folks got addicted to agriculture, they multiplied in number, established permanent villages and towns, and adapted a sedentary lifestyle.  They lived in greater concentrations, and became something like herd animals — highly attractive to parasites, similar to how wheat fields are highly attractive to locusts.

Steven Johnson wrote about the London cholera epidemic of 1854.  At the time, London was the biggest city in the world, and it was suffering from a population explosion.  One question tormented the minds of urban bureaucrats: “What the <bleep> are we going to do with all this shit?”  Londoners got their water from shallow wells in their neighborhoods.  Sewage and other wastes were stored in cesspools.  When your cesspool was full, the night soil men hauled the dreck out to farms, where it was applied to fields. 

As the city expanded, the distance to farms increased, as did the cost of removal.  So, more and more stinky muck remained in town.  Dung heaps grew to the size of large houses.  The entire city had a powerfully intoxicating aroma.  Parliament had to shut down during a heat wave 1858, when the flowing sewer known as the Thames River emitted the Great Stink.

The center stage of Johnson’s book was a well pump at 40 Broad Street, in the Soho district.  Near the end of August 1854, the six month old daughter of the Lewis family got sick and died.  Her soiled diapers went into the cesspool, and caused the biggest cholera outbreak in London history.  The cesspool was only accessible to the Lewis family.  Other tenants in the building “tossed their waste out the windows into the squalid courtyard at the back of the house.”  The cesspool was in the cellar, and the brick-lined well was just 32 inches (81 cm) away.  Oh-oh!

All the experts, except one, agreed that the cause of cholera was miasma — stinky air.  Since miasma was certainly the cause of the problem, the solution was to move the stink elsewhere.  So, in the name of public health, they built sewer systems, and directed the smelly crud into river.  Before long, “the Thames had been transformed from a fishing ground teeming with salmon to one of the most polluted waterways in the world.”  Meanwhile, the epidemics raged.

In this era, private water companies were also growing, in response to the trendy flush toilet fad (flushes filled cesspools even faster).  There was no unified city plan.  So, it was not uncommon for water company intake pipes to be just a bit downstream from sewer system discharge pipes.  Guess what happened.

Hans Zinsser was the scientist who identified the parasite that caused typhus, and then he wrote about its history.  Typhus has been a very popular disease for centuries — not among small groups of wild nomads, but among civilized people who live in dense concentrations.  The bacteria is transferred to humans via lice, and it favors folks whose personal hygiene habits were minimal to none.  In the good old days, taking a bath once in a while was not at all trendy.  Few if any baths were taken after October.

He wrote that prior to 1890, “Cities and villages stank to heaven.  The streets were the receptacles of refuse, human and otherwise.  The triangular intervals which one sees between adjacent medieval houses in streets still inhabited are apertures through which waste, pots de chamber, and so forth, could be conveniently disposed of from upper stories….” 

Typhus was really fond of soldiers, sailors, and prisoners.  At the conclusion of the First World War the victor was clear, “Typhus won the war.”  Epidemics in Russia killed 2.5 to 3 million people between 1917 and 1921.  John Gunther wrote that in the Congo, all Urundi women shaved their heads to avoid typhus (lice).

To be continued…

Here are my reviews of some disease-related books:

Bird Flu by Michael Greger

Epidemics by Geoffrey Marks and William K. Beatty

Health & the Rise of Civilization by Mark Nathan Cohen

Plagues and Peoples by William McNeill

The Antibiotic Paradox by Stuart Levy

The Ghost Map by Steven Johnson

The Plague of the Spanish Lady by Richard Collier