8

THE BIRDS AND THE BEES: USEFUL ANIMALS FOR THE STRANDED TIME TRAVELER

That dog you just domesticated isn’t fat. He’s just . . . a little husky.

Detailed in this section are eighteen of the most useful animals on Earth, alongside three notably horrible ones. Every animal on this list predates the evolution of anatomically modern humans (excepting of course the animals created by humans, such as dogs and sheep), so the good news is that any civilization with people in it has the potential to have these animals in it too.

Before you get too excited by visions of lions plowing your fields while giraffes keep a watchful eye on your herds, you should know that only about forty different animals were ever fully domesticated before the invention of time travel, and this list includes such obvious filler as goldfish, guppies, canaries, hedgehogs, finches, and skunks: species that are generally pretty useless to humans outside of being a reasonably adorable pet.* Unlike plant domestication—comparatively easy—an animal candidate species for domestication must:

• be useful to humans in some way (food, labor, fur, companionship, entertainment, good at dying to let us know when coal mines are filling up with carbon monoxide, just give us something)

• breed in captivity

• be easily contained, or naturally stay close to humans

• reach maturity quickly

• tolerate if not enjoy the company of both humans and other animals of its species

• be calm, docile, and not flip out when panicked

• eat food that’s found near humans or that humans can easily provide

• accept human presence, human captivity, and ideally human enlightened civilization-building leadership

If even one of these criteria is absent, your domestication attempt probably isn’t going to work, and you’ll just end up with a bunch of upset wild animals that now know exactly where you live. However, if all criteria are present, then you will have an animal that will accept being kept by humans, and that you can now selectively breed. Like in plant domestication, select individual animals that have the traits you want, encourage them to breed, and continue selecting for your chosen traits with each new generation. That’s all it takes, and this process of artificial selection will soon be producing animals more useful to your purposes—whatever you decide your purposes are—than those found in the wild.

What animal should you domesticate first? The most important thing your civilization can have is a large, four-legged, easily tamed, easily contained, and easily controlled vegetarian mammal, because such animals are miraculous do-it-all sources of meat, hide, milk, fur, transit, and labor. The best example found across all of human history* are horses: they can get you around, pull your plows, feed you, and provide clothing and even entertainment (i.e., watching the galloping steeds and then wagering money on the galloping steeds). If you look around yourself and see horses or protohorses (henceforth: “horsies”), great news: you and your civilization are playing on easy mode.* If you don’t see any horsies, look for substitutes like camels, llamas, and alpacas. Failing that, bison, cows, oxen, and goats don’t do everything horsies do, but they do at least provide meat, hide, and fur, which is better than nothing.

The bad news (both for horsie lovers and temporally stranded civilization builders) is that there are several times and locations throughout human history during which there aren’t any horsies or their substitutes available. Two times to watch out for in particular are:

• The Americas between 10,000 BCE and 1492 CE (i.e., after humans first arrived and before extensive European contact)

• Australia between 46,000 BCE and 1606 CE (again, after humans first arrived but before extensive European contact)

In both these cases, the arrival of humans corresponds with mass extinctions—including horsies and the horsie-adjacent—which left these continents bereft of useful pack animals until their later reintroduction from Europe.

• If you’re in the Americas between 10,000 BCE and 1492 CE, while there are no horsies or camels, there are llamas and alpacas in South America. In North America there are bison, but they can’t be domesticated, and good luck trying to get one to pull a plow. You’re the worst off if you’re in Central America during this time period, where you won’t even have bison. The best you can do while stranded here is domesticate smaller animals—wolves, turkeys, ducks—and try to substitute them as best you can for the larger, more useful beasts that are available to other civilizations elsewhere and elsewhen on the planet.

• Australia—always a special case since it evolved separately from the rest of the world once it separated from Antarctica around 85,000,000 BCE—is a place where marsupials* achieved dominance over other mammals, and horsies never appeared. However, from 2,000,000 BCE until 46,000 BCE there are diprotodons available to you: these giant hippo-sized wombats provide meat, milk, hides, can be ridden, will pull a plow, and have been domesticated by other time travelers.¹⁵ They go extinct when humans arrive on the continent, and while kangaroos and emus do survive contact with humanity, neither is well suited for transportation or for pulling a plow. As you require humans for your civilization, your best hope for easily building one in Australia is to be stranded around 46,000 BCE: after humans have begun arriving but before the diprotodon disappears. Protect the diprotodon from the humans and your civilization gets both humans and useful draft animals.

Examine the following pages to find animals native to your region. Like in Section 7: Putting Down Roots, each species is listed alphabetically: species that have been domesticated appear first, and those that haven’t appear after. Each includes the area they first evolved in. Depending on your time period, you may get lucky and find instances of these animals—of which only a few are blood parasites—outside of their native ranges.¹⁶

8.1: BISON (AMERICAN BUFFALO)

NATIVE RANGE

North America, Europe

FIRST EVOLVED

7,500,000 BCE

DOMESTICATED

Water buffalo were domesticated in 3000 BCE (India) and 2000 BCE (China), but American buffalo have never been domesticated.

USES

• Every part of the buffalo can be used: meat for eating, hides for clothing, sinews for bowstrings, hooves for glue (see Section 8.9: Horses for the recipe), and bones for fertilizer. If you’re throwing out buffalo parts, you’re doing it wrong!

NOTES

• They can get up to speeds of around 55 km/h, so watch out.

• If you’re in North America after humans show up and there are no horses or camels, you’ll still have buffalo. But they’ll fight you and won’t pull a plow, so maybe just eat them.

8.2: CAMELS

NATIVE RANGE

The Americas, Africa

FIRST EVOLVED

50,000,000 BCE (rabbit-sized camel ancestor in North America)

35,000,000 BCE (goat-sized ancestor)

20,000,000 BCE (camel-sized ancestor)

4,000,000 BCE (modern camels)

DOMESTICATED

3000 BCE

USES

• Like cows, camels are a good source of milk, meat, hides, and labor. Plus their dung is dry enough that you can burn it for fuel.

• You can live on camel milk alone for about a month! We wouldn’t recommend it, but it is an option if things are going that way.

• Two-hump camels are easy to ride: put the saddle between the humps. But what about one-hump camels? Humans messed around with saddles in front of and behind the hump before realizing around 200 BCE that building a wooden frame around it and putting the saddle on top of that worked best.

• Camels will tolerate saltier food and water than sheep or cows.

NOTES

• While mostly associated with Arabian deserts today, camels actually evolved in the New World, crossing over to Asia on a land bridge that existed around 4,000,000 BCE. Camels—along with horses, mammoths, mastodons, sloths, and saber-toothed cats—went extinct in the Americas around 10,000 BCE, shortly after humans showed up. This is a coincidence that has absolutely nothing to do with how extremely delicious these animals are.¹⁷

• Camels have a wobbly gait but can carry more than horses, and can go in places horses can’t. They’re also larger than horses, big enough to spook them in battle!

8.3: CATS

NATIVE RANGE

Eurasia

FIRST EVOLVED

15,000,000 BCE (last common ancestor with tigers and lions)

7,000,000 BCE (earliest cat-sized wildcats)

DOMESTICATED

7500 BCE (if cats can be said to be domesticated)

USES

• Cats are useful for killing vermin (mice, rats) but beyond that provide very little use to humans, except companionship, and even then only according to their capricious whims.

• Cats can be considered to be only “semi-domesticated”: domestication usually involves changes between domesticated and wild specimens, and wild and domestic cats show very few genetic differences.

NOTES

• Cats, like dogs, may also have been self-domesticating: as soon as humans started keeping grain around, it would attract mice and rats, which would attract the wild cats that hunt them. As the cats provided a useful service and asked very little in return, they could enter the fabric of human society easily.

• During the Black Death in Europe (1346–1353 CE, 50 percent of the human population there died, stay away if you can) cats were thought to carry the disease, and they were slaughtered en masse in an attempt to end the plague. Ironically, fleas carried on rats were one of the major disease vectors, and with no cats, the rat population exploded. Again: stay the heck away from Europe from 1346 to 1353 CE.

8.4: CHICKENS

NATIVE RANGE

India, Southeast Asia

FIRST EVOLVED

3,600,000 BCE (common ancestor between chickens and pheasants)

DOMESTICATED

6000 BCE

USES

• Chickens are a delicious source of both meat and eggs. Plus, they’re omnivorous, which makes them easier to feed than cows.

• To answer your question: the egg came first, as eggs evolved in other animals millions of years before chickens ever appeared.

• To answer your second, newly clarified question: the chicken egg also came first. Inside the first chicken egg was a zygote carrying a mutation that allowed it to become the first chicken. This egg, with a mutated zygote inside, was therefore laid by a protochicken. Evolution!

• Aristotle wasted a lot of time pondering this problem around 350 BCE and ended up concluding that both chickens and eggs must have always existed as two eternal constants in the cosmos. See? These are the kinds of conclusions you reach when you don’t know that evolution is a thing.

NOTES

• After first being domesticated around 6000 BCE in China, they reached eastern Europe around 3000 BCE (possibly through another domestication), the Middle East around 2000 BCE, Egypt around 1400 BCE, and western Europe and Africa around 1000 BCE, and they were brought to the Americas with European contact.

• Chicken eggs are an extremely versatile ingredient in cooking and baking! The proteins in eggs solidify when cooked, which makes them very useful as binding agents in all sorts of foods, including in the delicious hamburgers you no doubt will one day want your civilization to produce. Eggs are also used to add moisture, to thicken sauces, to leaven, to emulsify, as a glaze, and as a way to purify liquids (see Section 10.2.6).

8.5: COWS

NATIVE RANGE

India, Turkey, Europe

FIRST EVOLVED

2,000,000 BCE (aurochs)

DOMESTICATED

8500 BCE

USES

• One of the most useful animals to humanity, cows can be seen as machines that turn indigestible (to humans) materials like grasses into delicious meat, refreshing milk, tasty proteins, and heartening fats.

• They can be used to plow fields and transport goods and people, and their skin is a great source for leather.

• The usefulness of cattle makes them one of the oldest forms of wealth: if you have a lot of cows, you are doing pretty okay.

NOTES

• If you’re around before domestication, you won’t find any cows, but you may find aurochs: the wild animal from which cows were domesticated (more than once, actually). They’re bigger than cows—up to 2m tall—better muscled, and have giant horns, making them both the largest and most formidable animal ever domesticated. They appeared around 2,000,000 BCE in India, reached Europe around 270,000 BCE, and died out in 1627 CE. Auroch back-breeding attempts (using selective breeding to restore aurochs using genes remaining in current-day cows) began in the 1900s CE, but they were finally restored in 2033 using DNA sequencing done in 2010.¹⁸

8.6: DOGS (ALSO: WOLVES)

NATIVE RANGE

EVERYWHERE (though wolves first appeared in North America and Eurasia)

FIRST EVOLVED

1,500,000 BCE (wolves and coyotes diverge from a common ancestor)

34,000 BCE (first domestication of wolves)¹⁹

DOMESTICATED

20,000 BCE (first domestication of wolves that led to modern dogs)

USES

• All dogs evolved from domesticated wolves: sure, wolves are clever and cunning carnivores that hunt in packs and set traps to ambush their prey, but they rarely attack humans unless rabid or starving. Plus, wolves are where you get dogs from, so we will not hear any bad words said against wolves.

• How great are dogs? Besides being awesome pals, dogs are a great source of labor; good for vermin control; good for hunting, herding, and livestock guarding; and can also be used for food and pelts after they die (of natural causes, hopefully, after a long life of being an awesome dog).

• Plus, if you point somewhere, dogs can understand your intent and look to where you’re pointing. Wolves don’t do this, and neither do our closest extant relatives like chimpanzees and gorillas. In some ways, domestication has made dogs more humanlike than any other animal!

NOTES

• Farming will change your relationship with wolves. Until the invention of farming, humans and wolves can be allies, working together to hunt animals and sharing in the spoils. But after farming, wolves will attack what had become valuable farm animals, and they become adversaries to humans.

• Wolves/dogs were the first species domesticated (before even farming was invented) and have actually been domesticated more than once. In some instances dogs domesticated themselves: wolves that were gentler, cuter, and less afraid of humans could get more food from them than those that were vicious and kept their distance, and so there was selective pressure on increasingly doglike wolves, until they could be accepted into human society as companions.²⁰

• An experiment began in Russia in 1959 CE, trying to breed doglike animals from wild foxes by selectively breeding the “tamest” foxes with each other. In four generations some were wagging their tails when humans appeared, in six they licked human faces and wanted contact, and in ten about 18 percent of their foxes were doglike: calm, friendly, playful, solicitous of human touch. By twenty generations it was 35 percent, by thirty it was 49 percent, and by 2005—less than 50 years after the experiment began—100 percent of the foxes were being born tame, and the scientists now raise money to continue their research by selling the foxes as pets. You can do this with wolves in any time period. You can make yourself a dog.

• Wolves enter puberty around 22 months, so in a best-case scenario with ten generations, that’s only 220 months, or about eighteen years, to produce a pretty decent dog. Imagine how great it’ll be to have a dog after wanting one for eighteen years! It’ll be extremely great.

8.7: GOATS

NATIVE RANGE

Turkey

FIRST EVOLVED

23,000,000 BCE (common ancestor of both sheep and goats)

3,400,000 BCE (wild goat ancestor, the bezoar ibex)

DOMESTICATED

10,500 BCE

USES

• Goats are a source of meat, milk, wool, and hide, and can be used as beasts of burden too. Like camels, their dung is dry enough to be used as fuel.

• Goat milk is closer to human milk than cow milk is, meaning we can extract more nutrition from it, plus it’s lower in (sometimes-challenging) lactose. It’s also more homogenous than cow’s milk, which means it’s great for making cheese.

• Their downy undercoat—called “cashmere”—is terrific for sweaters, but it’s difficult to produce in large amounts.

NOTES

• Goats are actually extremely picky eaters—they often won’t eat food if it’s dirty unless they’re starving—but they’re very curious and will try eating basically everything.

• Goats (like all animals except humans and a few other primates) have no sensitivity to poison ivy. Since they eat it willingly, a few grazing goats are an easy way to get rid of this plant: just don’t pet them or drink their milk for a few days afterward.

• The bezoar ibex is a species of wild goat, found in the mountains of Turkey, from which all modern goats are descended.

8.8: HONEYBEES

NATIVE RANGE

Southeast Asia

FIRST EVOLVED

Bees: 120,000,000 BCE

First honeybees: 45,000,000 BCE

Modern honeybees: 700,000 BCE

DOMESTICATED

6000 BCE

USES

• Honeybees make honey, which, until you find other sources of sugar, is one of the few ways to sweeten food! It’s also energy-dense and easy to digest.

• Honey can also be used as a treatment for coughs and sore throats, and can be used to treat wounds in a pinch.

• Honeybees also make wax, which is great for candles, seals, and waterproofing clothing, and can be applied to tablets to make a reusable writing surface.

• Honey lasts almost indefinitely without rotting, so it is a very easy way to keep sugar around.

NOTES

• Finding wild beehives is pretty easy: just spot a foraging bee and follow her back to her hive.

• Botulism spores can contaminate honey, which is usually no big deal, but infants can be vulnerable to it so maybe keep your babies away from beehives (there are several reasons for doing that, actually).

• Honey has been harvested even before humans evolved, which is no surprise, since it is extremely delicious. Primates like chimpanzees and gorillas use sticks to collect honey from hives.

• Honeybees went extinct in the Americas around 10,000 BCE but were reintroduced by European colonists in 1622 CE.

8.9: HORSES

NATIVE RANGE

The Americas, Asia

FIRST EVOLVED

54,000,000 BCE (earliest dog-sized horses)

15,000,000 (horses big enough to ride)

5,600,000 BCE (modern horse ancestors)

DOMESTICATED

4000 BCE

USES

• One of the most useful animals to domesticate, horses provide meat, milk, hide, hair, bone, drugs (see Section 10.9.1: Birth Control), plus are useful in sport, transportation, war, and labor.

• The horse-drawn plow (see Section 10.2.3: Plows) greatly increases farming efficiency and is one of the fundamental inventions you’ll want ASAP.

• Horse hair is used to make bows for stringed instruments like violins, and horse hooves can be boiled to produce glue, which has been used since at least 8000 BCE.

NOTES

• The horse was the basis of long-distance communication from their domestication all the way until the 1800s. Until the invention of the train, the fastest speeds horses could travel at were also the fastest speeds humans could travel at!

• Making glue is easy: when a horse dies, break up the hooves into small pieces, boil them until they dissolve, and add some acid (the stomach acid from the same horse is a convenient source). This will set into a hard resin, which can be combined with hot water to produce glue when you need it!

• The earliest horses were clever, dog-sized animals that evolved in North America around 54,000,000 BCE. So if that’s where and when you’re trapped, while you won’t be riding any horses, you are going to have some adorable pets.

8.10: LLAMAS/ALPACAS

NATIVE RANGE

South America

FIRST EVOLVED

Cousins of the camel, alpacas and llamas have a similar evolutionary history, first appearing around 4,000,000 BCE.

DOMESTICATED

4000 BCE

USES

• Llamas and alpacas are a source of meat, milk, hides, and fiber, and can also be used for labor.

• After (other) humans (beyond yourself) show up in the Americas around 10,000 BCE, llamas and alpacas are the only pack animal left, and then only in South America.

NOTES

• Unlike most mammals, female llamas don’t have a reproductive cycle, but rather ovulate on demand after mating. Nice! This makes breeding them slightly easier!

8.11: PIGS

NATIVE RANGE

Europe, Asia, Africa

FIRST EVOLVED

6,000,000 BCE (early ancestors)

780,000 BCE (wild boars)

DOMESTICATED

13,000 BCE

USES

• Pigs give meat, hide, and, uniquely, toothbrushes. Pig bristles make a great toothbrush, which is great because human teeth are baloney.

• Here is the thing about human teeth: they’re the only tissue we’ve got that doesn’t self-regenerate. You cut your skin, it heals, but your teeth just sit there getting covered in plaque (food particles, which are unavoidable if you eat food, which you have to do to live) until they decay. Ridiculous!

NOTES

• Pigs were domesticated from wild boar several times, including around 13,000 BCE in the Near East, and again in China around 6600 BCE. If you’re around before that, wild boar first evolved in the Philippines around 780,000 BCE before spreading to Eurasia and North Africa.

• Careful eating pigs: their meat contains what you can call an “unusually high” number of parasites and pathogens, including E. coli, Salmonella, Listeria, roundworm, tapeworm, and more. You’ll be fine; just make sure you cook your pork all the way through!

8.12: PIGEONS

NATIVE RANGE

Europe, Asia

FIRST EVOLVED

231,000,000 BCE (earliest ancestors)

50,000,000 BCE (earlier ancestors that are safer to encounter)

DOMESTICATED

10,000 BCE

USES

• Originally domesticated as a food animal, they became way more useful when we realized that they can find their way back to their home nest even when released from an unfamiliar location up to 1000km away, making them useful for carrying messages.

• Up to the invention of the telegraph (1816 CE) pigeons were one of the very few methods of rapid long-distance communication available.

NOTES

• Pigeons are the first domesticated birds! They’re descended from the rock pigeons, which, like all birds, are descended from dinosaurs: a diverse group of animals that thousands of other temporal tourists have safely encountered between 231,000,000 BCE and 65,000,000 BCE in their FC3000™ personal time machine, and which you may also briefly and much more unsafely encounter, should you be unfortunate enough to find yourself stranded in that particular time range.

8.13: RABBITS

NATIVE RANGE

Asia

FIRST EVOLVED

40,000,000 BCE (early ancestors)

500,000 BCE (modern rabbit)

DOMESTICATED

400 CE

USES

• Rabbits are a convenient source of meat and fur: they’re small, pose absolutely no threat to hunters, and reproduce rapidly: so much so that predation is generally all that keeps their population in check, so don’t feel too bad about hunting these defenseless, adorable fur balls.

• Rabbits don’t require much space or food, and so can also be raised in the home for a convenient and inexpensive source of meat.

• The ease of growing and hunting rabbits may make you want to eat them exclusively, but heads-up: rabbit flesh is super low in fat. Not getting enough fats is fatal, which makes it possible to die of starvation while still constantly keeping your belly full of rabbit meat. Variety in your diet: it’s useful!

NOTES

• The earliest rabbit ancestors evolved in Asia around 40,000,000 BCE, but the modern rabbits you’re probably familiar with (the European rabbit) appeared around 500,000 BCE in the Iberian Peninsula, where they remained until being introduced elsewhere by humans. These rabbits have since been introduced to every continent except Antarctica!

• Introducing rabbits to new ecosystems has usually gone pretty poorly: without natural predators, rabbits reproduce “like rabbits,” hence the famous expression (that famous expression is “do not introduce invasive species to new continents; what are you thinking?”).

8.14: SHEEP

NATIVE RANGE

Western Asia

FIRST EVOLVED

23,000,000 BCE (common ancestor of both sheep and goats)

3,000,000 BCE (mouflon)

DOMESTICATED

8500 BCE

USES

• Sheep are a source of meat, wool, and milk (which is great for cheese, see Section 8.7: Goats).

• Sheep were the second animal to be domesticated, after the adorable dog. Initially they were bred for meat, until 3000 BCE, when the focus shifted to their wool.

• Until silkworms and cotton plants started being used to make clothes, most people wore leather and wool, so the sheep is a very convenient animal to invent and then keep around!

NOTES

• Domestication and selective breeding produced the super-woolly sheep you’re familiar with, so if you’re around before 8500 BCE, you won’t find any. Instead you’ll find mouflon, the animal from which sheep are descended. Mouflon have short reddish-brown coats, a white belly, white legs, and giant horns.

• After first being domesticated in the Middle East, sheep spread to the Balkans in 6000 BCE, and by 3000 BCE were spread throughout Europe.

8.15: SILKWORMS

NATIVE RANGE

Northern China

FIRST EVOLVED

280,000,000 BCE (first metamorphosing insects)

100,000,000 BCE (first silk-producing metamorphosing insects)²¹

DOMESTICATED

3000 BCE

USES

• Silkworms spin cocoons made of silk thread, which you can weave with the instructions in Section 10.8.4. Silk’s popularity has resulted in silkworms being one of the few insects to be domesticated!

NOTES

• Domestication didn’t work out too well for the silkworms though: those that emerge from their cocoons do so without the ability for sustained flight, and will not eat unless fed by humans. They live for only a few days—during which they mate and lay eggs—before dying.

8.16: TURKEYS

NATIVE RANGE

North and Central America

FIRST EVOLVED

30,000,000 BCE (turkeys split from chickens and other birds)

11,000,000 BCE (earliest turkeys)

DOMESTICATED

2000 BCE (Central America)

100 BCE (North America)

USES

• Chickens aren’t native to the Americas, but turkeys are a pretty delicious substitute.

NOTES

• Turkeys (like other birds, including chickens) can carry incredibly deadly diseases, including flus that can mutate to affect humans. See Section 3.5 for more.

8.17: BEAVERS

NATIVE RANGE

Europe, North America

FIRST EVOLVED

7,500,000 BCE (common ancestor of the North American and European beaver)

2,100,000 BCE (bear-sized cousins in North America)

DOMESTICATED

Never, don’t even try, their teeth never stop growing so they’re just going to chew up all your coolest stuff.

USES

• Beavers are (a) a source of meat, (b) a source of fur, and (c) a source of cutting down trees if you’re willing to wait and don’t particularly care about which trees get cut down.

• Beavers excrete a substance called “castoreum” (so named because humans once believed male beavers bit off their own testicles, castrating themselves, which is not true and really just tells you more about the humans who thought this than it does about the beavers) to mark their territory, and castoreum contains salicin, which is an anti-inflammatory agent in humans, and can also be used as an analgesic.

• Castoreum smells like vanilla, and this beaver juice was first added to mass-produced food in the twentieth century for this very reason—usually under the euphemism “natural flavoring.”

NOTES

• If being trapped in the past has given you a headache, try consuming beaver castor sacs. That’s where beaver castor comes from, and they’re in cavities under the skin between the pelvis and tail. They’re right beside the anal glands, so you’ll know when you’re close.

• Salicin can also be found in willow bark (Section 7.27), if you’ve got some of those trees nearby and would rather not get beaver glands all up in you.

• The bear-sized beavers that lived in North America died out around 10,000 BCE, the same time humans showed up.

• North American and European beavers can’t crossbreed: they’ve been separated for so long that they now have a different number of chromosomes. Evolution! It’s crazy!

8.18: EARTHWORMS

NATIVE RANGE

Worldwide (including Antarctica, before it became covered in ice)

FIRST EVOLVED

400,000,000 BCE²²

DOMESTICATED

Never: we never needed to, because they already do terrific work for free.

USES

• Earthworms move by forcing themselves into crevices (baby worms can move soil 500 times their body weight!), making them incredibly useful animals to have if you’re farming: they aerate and mix soil, improve drainage, and encourage plant growth. They’re a handy marker for soil health: lots of worms usually means fertile soil that your plants will have an easier time growing in!

• In poor soil you can expect only a few earthworms per square meter, while in fertile soul there may be hundreds living in the same space.

• Worms work as fish bait, and can be “charmed” out of the ground by tapping it rhythmically. Seagulls will dance on soil for this reason!

NOTES

• An adult earthworm can weigh around 10g, which can put at least 1kg of worm biomass per square meter of fertile soil. Multiplied across the size of a farming field, the weight of worms underground can outweigh the animals grazing above it!

• During ice ages, glaciers scrape away topsoil and wipe out any earthworms. In most of Canada and the northeastern United States, native worms died out during the last ice age (from 110,000 BCE to 9700 BCE). As worms migrate very slowly, the worms living in these areas in the modern era are descended from non-native varieties, brought over after European contact in 1492 CE.

8.19: LEECHES

NATIVE RANGE

Europe, Western Asia

FIRST EVOLVED

201,000,000 BCE

DOMESTICATED

Why would you want to?

USES

• Leeches show up as a medical treatment in 500 BCE and continue to be used in medicine until the late 1800s. That’s way too long to be attaching actual worms to ourselves hoping they’ll cure our diseases (they won’t) under the theory we have “too much blood” (we don’t).

• We’re mentioning them here in case you’re around humans in this colossal length of time during which they think putting a predatory worm on your skin to feed off you will help cure disease. It’s unlikely to harm you (leeches are full of parasites, but none that can survive in humans), but here is a true fact: it’s not going to do you any favors.

NOTES

• Leeches actually made a brief comeback in medicine in the 1980s CE, when it was found the anticoagulant in their saliva could be used in reconstructive surgeries. However, we soon figured out which protein in their saliva had that property and generated it synthetically, and then we once again didn’t need leeches anymore.

• So yes, when your civilization invents plastic surgery, you may have a brief use for leeches.

8.20: LICE

NATIVE RANGE

Worldwide

FIRST EVOLVED

12,100,000 BCE (hair and pubic lice, showing up when humans did)

190,000 BCE (body lice, evolving only after humans started wearing clothes)

DOMESTICATED

Again, why would you want to, what are you planning?

USES

• These parasites cover the world and were ubiquitous in human society until at least the Middle Ages. If there are humans around, you are probably going to have insectoid parasites sucking the blood out from your skull and then laying eggs in your hair, or “lice.”

• Lice species are closely tied to their hosts, and there are three types of lice that infect humans: head lice, body lice, and pubic lice. Head and pubic lice live in hair, but body lice live on clothing.

• Lice also carry diseases like typhus, which has been responsible for several epidemics throughout history.

• You know in old-timey paintings how rich Europeans would always wear those giant fancy wigs? That’s because they shaved their heads because their lice were so horrible. Wigs could still develop lice, but they could be more easily sterilized in boiling water.

NOTES

• Human lice evolved at the same time humans did—humans were breaking off from their chimpanzee ancestors at the same time their lice were breaking off from chimpanzee-feeding ancestors—so there’s no time period where you’ll find humans and not find lice. Sorry!

• Most rampant plague outbreaks on Earth occurred during winter. Why? That’s when wearing the clothes of a dead person is more likely. One single human with infected lice on his clothes could be responsible for a citywide outbreak of plague. Do not wear the clothes of dead people unless you boil them first, especially if they died of disease.

8.21: MOSQUITOES

NATIVE RANGE

Sub-Saharan Africa, now everywhere

FIRST EVOLVED

226,000,000 BCE (earliest mosquitoes)

79,000,000 BCE (modern mosquitoes)

DOMESTICATED

Please stop asking about domesticating human parasites.

Please.

USES

• Mosquitoes are a completely useless animal that also happens to carry viruses and parasites, and can inject you with malaria while you sleep. A flying, swarming blood ectoparasite that grows in water: terrific!

• The mosquito is one of the few animals that, if removed, would have no lasting negative impact on the world: the activities they perform in the ecosystem (feeding birds, some light pollination) are already performed by other insects. The only legacy would be fewer human deaths from malaria.

NOTES

• Mosquitoes are found all over the world, in every region except Antarctica, Iceland, and a few small islands. Oh well!

• They evolved before humans or even dinosaurs, so in any era in which you have either someone to talk to or something amazing to look at / be chased by, there’ll also be mosquitoes. Thanks, Earth!

• If you’re in Peru, look for cinchona plants (described in Section 7.7), which can treat the malaria spread by mosquitoes.