Ten Species that Changed Our World

Anyone who has given my website even a cursory glance knows that I enjoy learning about what life was like for ancient humans. I like knowing how different technologies and social structures came to be, not just because it’s interesting but because I think it makes for richer, more realistic worldbuilding for writing speculative fiction. I’ve been doing a lot of research into domestication lately, so @friendsofdarwin recommended Tamed: Ten Species that Changed our World by Alice Roberts to me on Twitter.

As is my usual habit, I got it in dead tree form via my local library, through the interlibrary loan process. Structurally, the book has ten chapters and an introduction, and centers around roughly three main narrative prongs:

• explaining the science behind our understanding of domestication process, what we know and how we know what we know.
• speculation about how ancient domestication events might have happened by telling a story of what-might-have-been, sometimes in ways contrary to conventional wisdom.
• discussions of ongoing genetic engineering and selective breeding efforts and the sociopolitical and ethical ramifications of it.

Overall, I liked Tamed a lot and found it useful, but my main gripe was that some of the speculative “it might have happened this way!” zoomed-in stories about the truly ancient domestication events felt pretty far-fetched. Since she starts out with one, it took me awhile to really get going with the book. Conveniently, the introduction played well to my pre-existing priors.

0. Introduction

In the introduction, Roberts makes two points that immediately resonated with me, not because they’re particularly new thoughts but because it set the tone that the book was going to be something that probably wouldn’t infuriate me for leaning into the kind of strict, overly abstracted categorization systems that I’ve come to hate from pop science and textbooks.

Since I was a kid, I’ve always been on the side of “humans are animals, too.” I really appreciated the way that Roberts took the time to point out that for the most part “natural” and “artificial” are not useful distinctions. It’s not a totally new argument — my social media feed is rife with variants of the “dihydrogen monoxide is responsible for thouands of deaths per year” meme, some more serious than others. My personal favorite are the ingredient lists for apples that people use to push back against the “if you don’t understand the words on the label, don’t eat it” movements. I always appreciate reminders that we’re not the only species exerting selective pressure on other species; honeybees on flowers, bears on apples, ants on aphids.

Domestication is just a really particular type of symbiotic relationship, when you think about it.

1. Dogs

Roberts begins the section on the domestication of dogs with a narrative sketch, a story detailing one potential way domestication of wolves might have happened. The trouble I had was that it was mostly pure speculation, and while I understand why she chose to fill in a lot of missing pieces with her “best guess” for the sake of storytelling — I would doubtless do the same thing if I were writing a fictionalized account of the neolithic era, and I don’t begrudge Jean M. Auel (much) for making up what she had to for the story to work in the Clan of the Cave Bear series — it was a bit disorienting for me, because my understanding is that there’s still some controversy about how exactly things went down.

If I’m reading this correctly, the latest genetic evidence from ancient & modern dogs points to a single origin just before the Ice Age between 21,000 & 17,000 BP. Scientific consensus seems to be coalescing around the idea that dogs were domesticated before agriculture by hunter-gathers, but we don’t know whether humans or wolves drove domestication.

As an aside, Roberts doesn’t touch on ravens at all, but Betty Coon Wheelwright has a really interesting article that shows how wolves established a similar symbiotic relationship with ravens. I touch on it in the analysis of my short fiction piece Gregarious: From hunting friend to wartime foe, but the tl;dr is that ravens are comfortable around wolves even if the wolf has never met a raven before in its life. They’ve evolved a symbiotic relationship with ravens as scouts and canines doing the heavy duty work hunting and busting open cadavers, then the ravens eat their scraps.

Anyway, the initial domestication of wolves into dogs could have been very fast, but what personally stuck out most to me was that domestication led to some dogs having omnivorous diets. I see all kinds of advertisements about how people should feed their pets a “natural” diet that’s high in meat because grain is bad for dogs, but apparently as far back as 9,000 years ago, dogs in China had diets that were up to 90% millet (a grain) and doing fine, thanks to having extra copies of the amylase gene, which causes a dog’s pancreas to produce the enzyme for digesting starch.

So while some dogs can’t handle grain, just like some humans have celiac’s disease or can’t break down lactose, many breeds (mostly from agrarian regions of the globe) evolved to do just fine on a high-grain diet.

2. Wheat

Speaking of grain, that’s what she tackles next. I skipped over some of the nitty gritty details about genetics research as irrelevant to me personally, but she did a really good job of clarifying for me the importance of a “tough rachis” — which I’ve been fuzzy on ever since I did my first deep dive on obscure agriculture facts. I really appreciated the clarity of Roberts’ explanation, which goes something like: the rachis is the stem of the plant, particularly a grass. On a tree, it’s the part with leaves that splits off from the main branch. On a grass, it’s the middle bit that all the “spikelets” split off of.

If you picture an ear of corn, a brittle rachis would be one where the kernals fall out of the ear super easily. This is beneficial for wild cereals, sort of like how dandelions benefit from seeds being only loosely connected to the plant — it allows for easier wind dispersal. A brittle rachis is like that except the rachis (stem) shatters outright instead of the seeds just getting dislodged.

What I found fascinating was the idea / proposal that the domestication process might not have consciously selected for tough rachis (i.e. where all the seeds stay on the ear), since it’s basically an inevitable consequence of harvesting and then moving the harvested cereals and then re-seeding a portion of the harvested grain; only the seeds that made it back to home base would get reseeded into fields and pampered with good soil and extra watering efforts.

She also advocates the idea that even though large grains are a sign of domesticated cereals, it’s possible this wasn’t consciously selected for either. Seedlings from large grains have more nutrients to work with and are more vigorous, but “cost” more for the parent plant to create. In the wild, seeds are far enough dispersed that it’s not worth the cost, but when densely packed into prepared fields, the cereals are mostly competing against sibling-plants and bigger ones do better.

Another thing that put wheat into perspective for me was the idea that grains of wheat are basically structured like chicken eggs, which is to says that a grain of domesticated wheat has three main components. The embryo is the seed, the bran that coats it (about 12% of the weight, probably comparable to eggshells), and then there’s the endosperm, which makes up 86% of the grain weight. The endosperm is where all the starch, oils, and proteins are. The endosperm is what got a lot bigger because of domestication.

Further hammering home her central thesis (for this chapter, at least) that domestication of wheat was probably less about human genius idly being genius, she points out that climate change was probably responsible for cereal domestication as a desperation food not an exciting new discovery of excellence and yum.

Basically the idea is that after the peak of the last Ice Age (around 20,000 years ago) things started to warm up, which was great for humans and the plants we eat because of the warmth and wet. There was also a rise in carbon dioxide levels. This led to a huge population boom for humans. But then the Younger Dryas period happened (around 12,900 and 11,700 years ago) and the cold snap reduced rainfall and warmth in the Fertile Crescent. This probably led to the cultivation of cereals, out of desperation, because why else would you eat something so tiny and fiddly?

I found this idea exciting because it feels more intuitively true than “humans casually and serendipitously discovered that bread happens by accident if you happen to be doing something else, then they kept making it because it’s yummy and awesome.” As someone who has baked bread, it is actually kind of a pain to make — and I wasn’t even starting from scratch! A nice pot of porridge is much easier, really.

Roberts posits that it’s not so much that “bread is a perfect food” (although it’s a bit easier to transport and eat with your hands than, say, porridge). Rather, the idea is that “there wasn’t enough normal food so people did what they had to do to make the available stuff edible.” Since there’s a lot more grass in the world than, say, fruit and nut trees, this may have led to the creation of bread. More on this when we get to yams.

But bread isn’t the only thing you can do with wheat. From the perspective of neolithic festivals it’s not even the most interesting.

Gobelkli Tepe predates stonehendge by about 6,000 years. Perhaps the world’s oldest temple, it has around 20 megalithic monumental stone circles with T-shaped pillars and low-relief carvings (of animals and geometric shapes). There are even three-dimensional sculptures. It’s unclear what their purpose was, but archaeologists suspect the site was used for ritual feasts (there’s definitely evidence for huge feasts) and gatherings of hunter-gatherers. The complex job duties requires to build such enormous monuments (quarrying, engineering, etc) indicate that complex societies and social hierarchies and job division pre-date agriculture, which really validates my thesis in the Beyond Rome: Infrastructure in Ancient Civilizations I did for Dan Koboldt’s “put the Fact in Fantasy” series.

Anyway, there’s speculation that instead of eating the grain, the folks who built Gobelkli Tepe might have fermented it into beer and “paid” laborers that way. Roberts points out that feasting culture might have even been responsible for the development of agriculture, which jives surprisingly well with things I’ve read in other sources — notably David Anthony, who says that during the early days of domestication, most food still came from hunting and fishing.

Roberts doesn’t cover this, but Anthony (who is basically the guy for studying pastoral economies of the Eurasian plains) says that agriculture (cattle-keeping and wheat cultivation) seemed to have been pursued part-time, as an insurance policy against bad years and perhaps as a way of keeping up with the neighbors, not as a replacement of foraging economy and morality. As animal keeping in the steppes spread, so did the rise of chiefs with lots of ostentatious ornaments. Their funerals were accompanied by the sacrifice of sheep, goats, cattle, and horses. The domesticated cattle and sheep that played such a large ritual role were eaten only infrequently, particularly in the east. In the Volga region (modern-day Russia), herders ate about 70% fish, with the remaining meat coming from game. Cattle and sheep were more important in ritual sacrifices than in the diet, as if they were initially regarded as a kind of ritual currency used for occasional sanctified meals and funeral feasts.

3. Cattle

The section on cattle focuses more on milk than it does on early herding, which was fine with me since I had thankfully already read a bunch of relevant stuff from David Anthony and Christopher Ehret about early cattle herding. Although Roberts touched on the fact that early herders kept domestic cattle mainly for their meat, main idea that Alice Roberts focused on was dairy products.

In the last chapter on humans, she talks about how the Roman scholars were writing about how milk was a good laxative, implying that lactose tolerance was relatively rare in Italy even in Roman times. It’s really common in Europe now, but only about a third of people in Kazakhstan produce lactase as adults.

Roberts’ primary point was that genetic selection for lactose tolerance in humans may predate deliberate milking of domesticated mammals. As evidence, she points to the fact that udders and their milk are seen as delicacies in modern hunter-gatherer cultures. She gives a couple of different examples, but my favorite is this:

A traditional story from the Central Plains of North America suggests that antelope udders and milk were considered to be a prized delicacy amongst hunter-gatherers there too. After hunting and killing doe antelope, two Kiowa chiefs were said to have argued over who should have the ‘milk bags’. One of the chiefs claimed both udders, and the other chief was so shamed by this affair that he upped sticks and took all his relatives with him, heading off to new territory in the north.

She goes on to say that there must have been more going on because of course nobody would ever storm off into the wilderness for something so minor, but I’m inclined to believe the oral tradition.

Oral traditions are often far more trustworthy than scholars are willing to believe and I’m sick and tired of Western scholars discounting things they are told because they can’t imagine a different cultural context than their own. Scholars discounted stories about women warriors and leaders for centuries because of their own narrow-mindedness, but Adrienne Mayor has an entire book collecting data proving that they were wrong to do so. Aboriginal Australians really did eat months, flood myths have a basis in real events. I could go on, but my point is, I need more evidence than “this doesn’t sound believable to me” to discount oral history being relayed by native people. Shame is a big deal in some cultures, and in many, starting new colonies can be as emotionally simple as moving away from your home town after college is for Americans.

Anyway, the idea that jives with information I’ve come across before, particularly this blog post over at Old European Culture discussing early cheeses.

That said, one of the things I really liked about Tamed was that Roberts took the time to explain not just what archaeologists and anthropologists know about ancient animals, but how they know it, in a pretty accessible way. Here’s a pretty good example:

When numbers of young cattle are high, this suggests a focus on rearing animals for meat. The shift toward older animals suggests that ‘secondary products’ such as milk and traction are becoming important. The first cattle and sheep were domesticated for their meat, and milking came later… except for in the Balkans, which had goat meat as soon as they had milk from goats.

Since young cattle grow fast and reach their mature size relatively early in their lifecycle, a large proportion of juvenile bones in midden heaps tends to imply that herders are keeping animals for their meat. Roberts posits that this is one reason that domestic cattle tend to be smaller than their wild counterparts — babies giving birth to babies leads to lower birth weights, and low-weight babies grow up to be low-weight adults.

I’m not an expert in evolution or genetics or anything but this doesn’t feel like the whole story. My mind immediately jumped to a phenomenon well known to watermen in the Chesapeake Bay region; when the government made it illegal to catch and keep crabs and fish under a certain size, fish and crabs started taking longer to reach that size on average. Natural selection pressures were favoring fish that grew more slowly, and that were predisposed to staying smaller. I don’t really know how I would go following up on this idea, but it does make me wonder whether herders early on in the domestication process weren’t so much following a strict “we slaughter every 2 year old calf” schedule so much as “we slaughter calves of a certain size.”

The last main point in this chapter was about the genetic fragility of modern cattle, because the populations are really fragmented and there’s a lot of inbreeding to produce the traits modern markets prize. Since there’s only really one species of modern cattle and the wild ones are pretty much extinct, we’re at real risk of having cattle go the way of the banana or American chestnut.

4. Maize

This chapter was mostly a technical discussion about whether corn originated in the highlands or the lowlands. The conclusions had to do mostly with phenotype plasticity, which is basically when environment changes how genes are expressed. The original maize plants were domesticated in one region, then when they moved to a different region, started looking like the maize from that region, which confused researchers for awhile.

A much more interesting (to me) article about maize was Domestic Storage Behavior in Mesoamerica, which goes really in depth about how maize impacted Mesoamerican culture. It covers why monocrop agriculture doesn’t work well in tropical ecosystems and how that affects centralization of power. It goes into detail about how the complexity required for different maize storage facilities impacted taxation and housing layouts, how maize is processed, and more.

Roberts mostly focused on genetics, which is much less interesting to me.

5. Potatoes

The section on potatoes was much better. Roberts explained how poor quality foods that grow underground — ginger, turnips, carrots, garlic, etc — were a fallback food for early humans in Africa, because they were consistently available but generally tough and hard to eat. She explains that two early developments — an increase in the amount of enzymes in our saliva that can break down starch, and the advent of cooking — helped early humans make use of starchy tubers like potatoes. She even posits that these kinds of tubers and rhizomes were more important than meat in allowing our ancestors to evolve big, energy-intense brains.

My mind immediately went to naked mole rats, which are one of my favorite animals. They’re basically mammalian ants native to the desert areas of the Horn of Africa. I talked about them some in my newsletter about thermoregulation but they’re neat because they’re functionally cold-blooded, with no ability to internally regulate their own temperature, and live in big colonies with only one breeding female. They manage their temperature by building nests with at soil depths with favorable air and temperatures, and live off a diet of tubers.

Potatoes themselves are native to the Americas, and although we’re kind of shaky on exactly how they got to Europe, they were spread by the Catholic church. My favorite tidbit of why they were useful is that, in the wake of the Seven Years War, potatoes did better than cereal grains like wheat because after being trampled by an army, you can still harvest a field of potatoes.

My second favorite tidbit was that the Inca used freeze dried potatoes as a form of currency. Early varieties of potatoes were pretty bitter, and so needed to be processed. To make the potatoes last longer and be more palatable, the Inca would freeze-dry their potatoes. They would leave potatoes on the ground overnight to freeze, then in the bright sun to thaw and let water evaporate. After a few days of this, they would walk on the potatoes to squeeze out any remaining water, creating chuño — which can last for decades. It reminds me a bit of how wine used to be made by by women dancing in tubs to crush the grapes with their feet, or how ice-wine is made.

Incidentally, this method is still used today, but the reason I mention the Inca specifically is because Incan peasants would pay their taxes with freeze-dried potatoes. Laborers and mercenaries were in turn paid from the potato stores. It reminds me a bit of how Roman soldiers were given flour rations to make their daily bread from.

I tend to care about that sort of history — which is why the section on maize was relatively disappointing — but Roberts focused more on how the nature of “seed” potatoes limit genetic diversity, because our habit is to grow potatoes from the “eye” nubs instead of actual seeds. Since this is functionally cloning, it reduces genetic diversity, which “freezes” the ability of potatoes to adapt to threats like climate change, pests, and disease. Meanwhile, pets and diseases keep on improving their ability to leverage potatoes for their own uses, making potatoes more and more reliant on humans to defend them.

On the one hand, it’s kind of the standard story of domestication — plant or animal gives up traits that help it survive in the wild in order to get human help. On the other, we lost the American chestnut and an entire breed of banana and this is the first time in human history that our infrastructure has been this global, so I do see her point.

6. Chickens

It turns out that chickens as we know them are basically a modern invention. We have evidence of chickens dating all the way back to Egypt, but they were mostly kept egg-layers, when they were kept for food at all. Apparently, Roman-era Britons kept chickens mostly for use in cock-fights; they would no more eat a rooster (or chicken egg) than your average American is likely to eat horse meat. Prior to the Benedictine reforms, most Europeans ate pheasant and geese.

I’m not terribly knowledgeable about the history of the Catholic Church of Medieval England, and Roberts doesn’t go into much detail, but the Benedictine Reforms seem to have been an attempt to wrest control of land and power from secular influences and to unify the political power represented by religious institutions into one set of rules. It was a fundamentally conservative movement trying to bring back past glory by living more strict lifestyles.

One such rule was the prohibition of consuming four-legged animals during fasting periods. Since fish, eggs, and two-legged animals were considered okay, chickens got more popular. They went from making up about 5% of midden heaps to 15%, and the gene for chicken “plumpness” started to become widespread as people bred for more delicious chickens.

Most of this chapter is devoted to a corporate contest in the 1900s to breed the best chicken for eating, and how the FDA is standing in the way of even small beneficial genetic engineering attempts to change a single pair of genes in modern chickens for the better. She notes that China is more likely than America to develop good genetic engineering technology, and has a whole section devoted to how silly this is because we don’t have a problem with eating stuff that was the product of irradiation, like ground nuts and rice. There wasn’t a ton of time or energy devoted to the times that technology messed things up for people badly — for example, there was definitely an opportunity to talk about pellagra in the maize section, since pellagra was caused by new technology for cheaply processing corn and a multi-decade refusal by the US government to require vitamin supplements to ensure it wouldn’t cause malnutrition. I was disappointed that the our terrible track record for safely feeding people with the products of technology wasn’t really addressed.

Scott Alexander does a better job at even-handedly discussing the failings of the FDA and the ways in which Chinese approach to infrastructure and technology is helping them gain geopolitical power.

7. Rice

The section on rice continued in the same vein as the piece about chicken genetics, with relatively little focus on the origins of rice. The main focus is modern GMOs, with only a bit about how rice paddies are less about rice needing swampy areas to grow well and more about excess irrigation being a great weed suppression mechanism if the grain can handle it.

Being passingly familiar with modern news, the whole controversy about golden rice as a solution for Vitamin A deficiency in high-rice diets was not new to me so I mostly found myself skimming this chapter. I did appreciate the reiteration that many technological leaps forward are driven not by random scientists being chill and smart and more by necessity in times of crisis.

Throughout the whole book, Roberts goes out of her way to present “a very different view of human history than perhaps we’re used to. Not a series of triumphant advances, driven by sheer ingenuity and inventiveness, but a story of misfortune and accidents, contingency and serendipity.” It’s a compelling argument that would be a lot more interesting to me if it hadn’t been buried in the middle of an deep-dive evaluation of Monsanto’s public relations efforts.

8. Horses

Roberts’ section on horses was a nice summary of the horse bits in David Anthony’s The Horse, The Wheel, and Language, but since I’ve already read (and reviewed)The Horse, The Wheel, and Language and some of the later literature in this vein, I didn’t learn much. This isn’t Roberts’ fault, since we were working off the same resources, but it did make me feel a lot more confident about my research, because there was one moment in particular that made me roll my eyes.

During one of her “imagine if” sections she posits that perhaps some teenager dared their friend to hop on the back of a wild horse and that sort of adventuresome spirit maybe led to early horseback riding, but as fun as the mental image is, it flies in the face of what I took to be the whole point of Anthony’s work (which Roberts uses as a source!) — namely, that horses were first domesticated as meat animal, not for transportation or for milk. Since this should have been fairly obvious given that she gives basically the same timeline for cows, I found the “possibility” to be an irresponsible inclusion at best.

That said, I did learn one cool thing: horses made it to South America around three million years ago thanks to Panama rising out of the ocean; before then, there were only volcanic islands in a chain to connect the two landmasses.

9. Apples

I went in to this chapter knowing almost nothing about apples other than the fact that the Biblical “forbidden fruit” probably wasn’t one (pomegranate? wheat? I’ve heard a billion theories. Roberts says that apples only recently started being grown in Palestine, which I found an interesting word choice mostly because the Palestine / Gaza Strip thing is super political and when I think “Biblical” I think Israel in general, or the Levant, or even “the Middle East,” but the big about apples being new to Palestine is … really specific and I’m not totally sure what to make of it.

Anyway, apples as we know them in the West are hybrids. Apples that actually taste good definitely come from the foothills of the Tian Shan mountains in Central Asia. The mountain range runs along the border of China and and Kazakhstan, but apples apparently can be traced to the foothills of these mountains and, according to Roberts, the specific city of Almaty, which I had never heard of but would totally love to visit. Roberts doesn’t touch on it but in later research I discovered that other fruits, including pears, plums, peaches, strawberries and raspberries, are also native to this region and still grow wild there. Thanks to this book, visiting Almaty is on my bucket list, so there’s that.

Apparently a lot of really Eurocentric scholars insisted for an appallingly long time that the (small bitter, sour, tart) crabapple was the “true” originator of the modern (sweet, big) apple, which isn’t true. What geneticists can prove is true is that as the apple spread, it hybridized with local plants, such that the modern apple actually does have a big chunk of crabapple in it, since crabapples do better in European climates.

But this chapter really focuses on grafting, where you can mix and match trees together to, for example, get a really hardy root stock supporting branches with particularly good fruit. Grafting is at least 3,000 years old, and was practiced by both the Chinese and the Babylonians. I’ve already heard of it though, thanks mostly to Atlas Obscura articles about, for example, the Tree of 40 Fruit at Syracuse University in New York.

But while I wasn’t super interested in the mechanics of grafting, I did find the explanation of how grafting may have been initially discovered pretty interesting.

Apparently, you can bend willow and fig trees to make tent frames. People can even make fences from the withies — touch, flexible branches. Even if you cut the withies, they will often take root and grow. Regardless, over time, the withies will merge and meld with each other where they touch, which surely folks returning to the same campsite year after year — or using an organic fence at a particular location — would have noticed.

As much as I winced at a couple of the “imagine if” scenarios in this book, I appreciate that Roberts used this kind of storytelling mechanism, because at least she was willing to venture an evidence-based guess and demonstrate realistic speculation for how early history might have looked — because I get really frustrated when scholars just shrug and say “we don’t have enough evidence to be sure.”

Takeaways

Overall, I’m glad I picked up the book. I learned some neat tidbits about history and biology and domestication and humans, which is something I’m pretty much always down for. More importantly, I got a lot of validation out of reading it. Here’s this famous biological anthropologist and biologist who goes on BBC a bunch and has done a ton of … and the stuff she’s saying isn’t all that different from the stuff I’ve been learning on my own.

It made my impostor syndrome a little more manageable, and I learned a bunch, too.