Notes

Chapter 1

1. Even traditional peoples in the least diverse places on earth eat or ate a more diverse diet than most of us do now. The Inuit, for example, are sometimes described as seal eaters because they lived so far north that little else was available. Yet the Inuit also ate walrus, beluga whale, bowhead whale, caribou, polar bear, musk ox, birds, bird eggs, fish, crowberries, cloudberries, grasses, fireweed, roots, and seaweed.

2. This even trickles down to the wildlife in cities. Urban ants and foxes in the United States have bodies in which many of the carbon atoms seem to be derived from the corn and sugarcane in their rubbish-enriched diets. See Clint A. Penick, Amy M. Savage, and Robert R. Dunn, “Stable Isotopes Reveal Links Between Human Food Inputs and Urban Ant Diets,” Proceedings of the Royal Society B: Biological Sciences 282, no. 1806 (May 7, 2015).

3. Bananas were domesticated in tropical Asia and Papua New Guinea. In these regions, the ancestral bananas and many of the domesticated varieties are pollinated by bats. The plants then produce seeds from which new banana plants grow. But at some point in the domestication of bananas, another approach to growing the plants emerged. They could be replanted from pieces of banana roots, the suckers. This proved much easier than waiting for pollinators and seed production, and, with time, varieties of bananas evolved that were unable to produce seed. They did no worse than those that produced seeds, thanks to humans, and maybe even a little better. They spread. As a result, nearly all the major banana varieties planted outside of tropical Asia are clonal.

4. The Dutch brought coffee to Ceylon as well as to several other islands in the East Indies, including Java.

5. Before the arrival of coffee rust, one-third of the world’s coffee came from Asia and Africa. After the rust, less than 5 percent did. See William Gervase Clarence-Smith, “The Coffee Crisis in Asia, Africa, and the Pacific, 1870–1914,” in The Global Coffee Economy in Africa, Asia, and Latin America, 1500–1989, ed. William Gervase Clarence-Smith and Steven Topik (Cambridge, UK: Cambridge University Press, 2006), 100–119.

6. Randy C. Ploetz, “Fusarium Wilt of Banana,” Phytopathology 105, no. 12 (2015): 1512–21.

7. Elected in 1950, Jacobo Arbenz was Guatemala’s second democratically elected leader. He proposed to redistribute abandoned banana land to poor farmers in the country and paid United Fruit Company twice what it had paid for the land. Arbenz believed that this would be the first step in creating a better country for his people, a democratic country. The United Fruit Company had other plans. Its leaders persuaded the US government to authorize the CIA to overthrow Arbenz as part of Operation PBSUCCESS. The director of the CIA, Allen Dulles, and the secretary of state, his brother, John Foster Dulles, were both friends of executives of the United Fruit Company. They had even done legal work for the company earlier in their careers. The Dulles brothers helped to convince president Dwight D. Eisenhower of the need to overthrow Arbenz. It was a secret and, from the perspective of the United States, successful coup. As a result, Guatemala’s democracy slid into decades of military dictatorship and a brutal civil war. That war would cost the lives of more than two hundred thousand Guatemalans, many of them at the hands of government security forces. The coup also set back democracy in other countries in which the United Fruit Company wielded power. However one attributes blame for these horrors, they, too, are part of the story of the Gros Michel banana.

8. If you want to know what the Gros Michel tastes like, you can go to parts of Asia where Panama disease has not yet arrived and where the Gros Michel can still be grown. Or you can buy artificial banana flavoring. Consumers often say that artificial banana flavoring doesn’t really taste like a banana; rather, it tastes more like a banana than a banana does. What it tastes like is the Gros Michel, the prototype used to craft the flavor in the first place.

9. From the Food and Agriculture Organization of the United Nations, at http://faostat.fao.org/.

10. Colin K. Khoury, et al., “Increasing Homogeneity in Global Food Supplies and the Implications for Food Security,” Proceedings of the National Academy of Sciences of the United States of America 111, no. 11 (2014): 4001–6.

11. One banana expert I talked to, Gert Kema, at the University of Wageningen, suggested that the good news for the banana is that varieties resistant to both to the new variety of Panama disease (Fusarium) and to another pathogen, Black Sigatoka (Mycosphaerella fijiensis), are being produced using transgenic approaches. The bad news is that such varieties, if they are really resistant, are a decade or more from coming to market. Varieties bred using traditional approaches are even further off. More money, Gert notes, would make all of this go faster, but as he is also quick to point out, more money does not usually materialize until the tragedy is at hand. Meanwhile, we must do all we can to control these pathogens where they have already arrived, and to prevent their spread.

Chapter 2

1. A note here on language: first, a disease is the illness that an organism suffers from. For example, AIDS is a disease. Most diseases are caused by biological agents. These organisms are called pathogens. The pathogen that causes AIDS is HIV. In the context of the potato famine, late blight was the disease the potato suffered from; whether it was caused by a pathogen would remain to be seen. A parasite is, in turn, an organism that lives in or on its host at some cost to that host’s fitness. A parasite, such as the larvae of a butterfly on a plant, might weaken its host without causing some specific disease state. The definitional boundaries between pathogens and parasites are fuzzy at best.

2. P. M. Austin Bourke, “The Use of the Potato Crop in Pre-Famine Ireland,” Journal of the Statistical and Social Inquiry Society of Ireland 21, pt. 6 (1967–68): 72–96.

3. Still, even before the famine the people’s healthiness was offset by their near total lack of possessions, including clothes. Children ran barefoot; adults, too. Underwear was nonexistent, and shirts and pants were mosaics of patches and holes.

4. Potatoes lack only vitamins A and D, both of which can be acquired from milk if there is a cow around. Potatoes sustain not only in terms of their quality but also—and especially—in terms of their quantity. Potatoes, sweet potatoes, and other crops that have underground storage organs maintain an advantage over seed crops such as corn and wheat. In theory, one could breed a corn or wheat plant that produced as much food per stem as a potato does, but the plant would fall over.For example, a potato can weigh as much as ten pounds or more. A corncob rarely weighs more than one pound. Picture a ten-pound potato on top of a cornstalk. In this image, you have a precise understanding why root crops are so successful, particularly in places where the amount of food produced per acre must be as high as possible. Like a jellyfish, a potato knows no bones or bounds; it simply grows.Initially the fecund sustenance of the potato provided the Irish with a way of living better. Potatoes were added to the crop rotation and planted in land that was fallow. By doing this the Irish as much as doubled the productivity of their land. The potato filled in the fallow spaces; it also filled in the fallow times. Potatoes could be harvested in the summer, when the grains were not yet ready and winter stores had run out. Over the course of generations, however, this luxury turned into dependence.

5. Sometimes rendered just vastatrix rather than devastatrix. Systematists love to argue about and play with the names of species.

6. Morren was not the first to suggest applying copper sulfate, nor would he be the last. Matthew Maggridge lived near a smelting factory, for instance. He noticed that potatoes growing near the factory’s chimneys, out of which billowed copper smoke, tended to be less infected.

7. With C. E. Broom, Berkeley had written the classic “Notices of British Fungi”; he was also the author of “Outlines of British Fungology.”

8. In 1879 he donated this enormous collection to the Royal Botanic Gardens, Kew, where it remains.

9. You should pause to contemplate the astonishing recentness of our modern sense of germs.

10. It started not with the potato late blight but with another disease affecting potatoes, leaf curl. Leaf curl arrived in the 1760s in Europe. We now know it to be caused by a virus. In the 1760s people blamed it on the degeneration of potato seeds. After all, the royals of Europe seemed to degenerate over time, their noses ever more crooked and their children ever less capable; why wouldn’t the same thing be true of potato seeds? Then in 1841 another disease arrived: dry rot. Again the experts blamed it on the degeneration of the seed, that and bad weather. But Carl Friedrich Philipp von Martius had another idea; he thought that perhaps a fungus was to blame. Martius, the curator of the botanic garden in Munich, was highly regarded. But most other scientists dismissed his hypothesis. His idea that fungus could cause disease—well, it was silly. Martius wrote, “A fungus, fusarium, is the cause of dry rot.” Other scientists said no. Martius was right and the other scientists were wrong, but Martius’s hypothesis was nearly completely ignored.

11. We now know these organisms to be oomycetes (see page 23) rather than true fungi, a distinction that would not be made for many years.

12. It is perhaps appropriate that Montagne contributed to the confusion over the right name for the species. He is often called Jean Montagne in articles about the history of late blight, but he went by the name Camille. His full name was Jean Pierre François Camille Montagne.

13. In his classic The Advance of the Fungi, E. C. Large describes readers of The Gardeners’ Chronicle as “the prosperous English gentlefolk, who went in for luxury gardens.” It was a magazine in which agricultural science of general interest was discussed, but this general interest was geared toward the affluent rather than those with little more than a potato and a wooden hoe, on whose backs much of European agriculture at the time depended.

14. From John Kelly, The Graves Are Walking: The Great Famine and the Saga of the Irish People (New York: Henry Holt, 2012).

15. William Wilde, “The Food of the Irish,” Dublin University Magazine 43 (1854): 127–46.

16. He had not, but he was trying to figure out whether the weather might have played a role in the severity of the blight and the speed of its spread. He had noted that excessive rainfall might have caused the plants’ tissues to be too full of water, but he considered the more likely scenario to be that the blight, having evolved in the wet places where potatoes are native, might spread more readily when conditions are damp.

17. Kingdom Stramenopila, phylum Oomycota, a group typified by its motile, spermlike spores.

18. Here common names get confusing. Blights are sometimes oomycetes, as is late blight of potatoes, and sometimes fungi, as is leaf blight of rubber.

19. E. C. Large writes, vividly, that “if a man could imagine his own plight, with growths of some weird and colourless seaweed issuing from his mouth and nostrils, from roots which were destroying and choking both his digestive system and lungs, he would have a very crude and fabulous, but perhaps instructive idea of the condition of a potato plant when its leaves were mouldy with Botrytis infestans.”

20. E. C. Large, The Advance of the Fungi.

21. A letter in L’Independance Belge, August 14, 1845, reprinted in the Monthly Journal of Agriculture 1, no. 8 (February 1846): 389.

22. We now know that in the early 1800s, across Europe, farmers used copper sulfate in various mixtures to treat a variety of pathogens. They treated not only seeds and cereals but also, for example, foot rot in sheep. In addition, copper sulfate was used to preserve objects made of wood, including wooden vineyard stakes. It is likely that the value of copper sulfate in dealing with powdery mildew was noticed by many farmers who would have noticed that there was less mildew in areas near their stakes than in areas far from them. See George Fiske Johnson, “The Early History of Copper Fungicides,” Agricultural History 9, no. 2 (1935): 67–79. Fiske provides an excellent review of the surprisingly fascinating (I swear) history of copper fungicides.

23. Another element of the solution, one adopted more readily though still not until the 1870s, concerned the methods by which potatoes were being grown. Jens Ludwig Jensen, a Danish scientist, used experiments to determine which approaches did and did not forestall the growth of the blight. Making hills around the potato plants helped keep the sporangia of the blight from washing onto the potato tubers. Getting rid of the foliage before pulling potatoes out so the foliage didn’t contaminate the potatoes also helped, as did cleaning out storage bins, particularly those containing infected material. None of this was very sophisticated, yet it was a vast improvement on what was, at the time, being done. It was, in essence, public health and hygiene for potatoes.

Chapter 3

1. John V. Murra, “Andean Societies Before 1532,” in Colonial Latin America, vol. 1 of the Cambridge History of Latin America, ed. Leslie Bethell (Cambridge, UK: Cambridge University Press, 1984), 61–62.

2. Columbus himself repeatedly bemoaned the fact that although he had clearly found a realm full of many valuable species, he could not tell which was which. As a result, when he did find something he thought he knew, or that he thought might be valuable, he gathered a bunch of it and hoped it could be planted back home. Sometimes he and those who followed him gathered things as a record of the uniqueness of the Americas. On his first voyage, Columbus killed a large snake that he thought the queen would just adore. More often what was gathered were things that could be planted back home, or at least things the conquistadors thought could be planted.

3. Because the conquistadors often married Native American women who then cooked for them, to a great extent Native American women would prove a key factor in what was gathered and what was not. Native American women prepared traditional dishes, but they would have tended to favor those that appealed to the palates of the conquistadors, even though the dishes were composed of native ingredients. Bread made from corn, for instance, to some extent fulfilled the desire of the conquistadors for wheat.

4. A historian whom I asked about this behavior said, “Well, Rob, you know the past is a foreign country,” which I take to be his way of saying, “I don’t have a clue, either.”

5. James Lang, Conquest and Commerce: Spain and England in the Americas (New York: Academic Press, 1975), and Geoffrey J. Walker, Spanish Politics and Imperial Trade, 1700–1789 (Bloomington: Indiana University Press, 1979).

6. The botanic garden established by King Carlos III of Spain in 1788 for testing (acclimatizing) plants before they were transported on to the European continent (Jardín de Aclimatación de la Orotava) still functions in Puerto de la Cruz, on Tenerife.

7. Domingo Ríos, et al., “What Is the Origin of the European Potato? Evidence from Canary Island Landraces,” Crop Science 47, no. 3 (May 2007): 1271–80; Mercedes Ames and David M. Spooner, “DNA from Herbarium Specimens Settles a Controversy About Origins of the European Potato,” American Journal of Botany 95, no. 2 (February 2008): 252–57.

8. When planted clonally, via seed potatoes rather than seeds, potatoes don’t require pollinators. Yet while this was a useful feature of potato production for the Irish initially, it would prove a problem later, inasmuch as it reduces the diversity possible among potato seeds. Similarly, potatoes are typically not thought to “need” specialist microbes associated with their roots in order to help their roots find nutrients, but it has been shown that potatoes grow many times faster with specialized potato bacteria on their roots than without them. As far as I can discern, no one has studied whether the potatoes introduced to Europe from the Americas brought their specialist beneficial bacteria with them. See J. W. Kloepper, M. N. Schroth, and T. D. Miller, “Effects of Rhizosphere Colonization by Plant Growth-Promoting Rhizobacteria on Potato Plant Development and Yield,” Phytopathology 70, no. 11 (1980): 1078–82.

9. James Lang, Notes of a Potato Watcher, Texas A&M University Agriculture Series 4, ed. C. Allan Jones (College Station: Texas A&M University Press, 2001). See the chapter entitled “The Andean World” for a nice description of the sophistication of Inca agriculture.

10. Similarly, the crops and animals of Europe arrived in the Americas largely without context. Those that survived and prospered were not the tastiest but rather those that were able to complete the entire journey. Columbus, for example, believed that the first colonists he left on Hispaniola failed to thrive (and even to live) because of the absence of European foods. They needed, he thought, fresh meat, almonds, raisins, sugar, honey, wheat, chickpeas, and wine. When he returned, he brought all these things with him, alive. Cows, horses, a few kinds of pigs, and chickpeas all survived. Wheat did poorly and was abandoned. But in each case what he brought was a subset of what he might have brought—a few varieties where thousands were known, varieties Columbus happened to have access to, varieties that are still farmed.

11. The true seeds of potatoes are unpredictable, thanks to sex. Sex mixes up the genes of two parents and helps create offspring that are different from either parent. When conditions are predictable, sex can pose a problem because some sexually reproduced offspring are likely to be less adapted to the environment than would be clones of either parent. But when conditions change (or new pathogens show up), sex is key to producing at least some offspring able to survive the new conditions. In potatoes, sex depends on pollinators, animals that carry pollen from the male parts of one flower to the female parts of another and, in doing so, fertilize the latter. Perhaps shockingly, we know very little about which species pollinate potatoes in their native range and which pollinate the wild relatives of potatoes. The male parts of potato flowers, like those of many other plants in the family Solonaceae, including tomatoes, only release their pollen when “buzzed” at just the right frequency. It appears that the animals with the right frequency are probably mostly bumblebees, but which bumblebee species do the best job and whether this has changed through time, along with many other details, remain largely unknown. Most of the relatively few studies on potato pollination have focused on potatoes living in North America and Europe, far from the bees and other insects with which they evolved. See, for example, Suzanne W. T. Batra, “Male-Fertile Potato Flowers Are Selectively Buzz-Pollinated Only by Bombus terricola Kirby in Upstate New York,” Journal of the Kansas Entomological Society 66, no. 2 (1993): 252–54. If you are a student and think it is ridiculous that we don’t know more about the pollination of potatoes in the Andes, read the following to get yourself started: C. F. Marfil and R. W. Masuelli, “Reproductive Ecology and Genetic Variability in Natural Populations of the Wild Potato, Solanum kurtzianum,” Plant Biology 16, no. 2 (2014): 485–94.

12. CGIAR’s many centers are essential to continued research on tropical and subtropical varieties of crops. The centers also serve as facilities for seed storage, crop breeding, and, as often as not, work that improves conditions for farmers.

13. Lang, Notes of a Potato Watcher, 61.

14. For those in the know—blight hipsters, as it were—the particular variety was isolate POX67, belonging to the EC-1 lineage. See also Willmer Pérez, et al., “Wide Phenotypic Diversity for Resistance to Phytophthora infestans Found in Potato Landraces from Peru,” Plant Disease 98, no. 11 (November 2014): 1530–33.

15. Robert Rhoades, “The Incredible Potato,” National Geographic 161, no. 5 (May 1982): 676.

16. It is said that the annual harvest of potatoes alone, not to mention other Andean crops, exceeds the total value of all the gold and silver brought back from the Andes.

17. Jean B. Ristaino, et al., “PCR Amplification of the Irish Potato Famine Pathogen from Historic Specimens,” Nature 411 (June 7, 2001), 695–97.

18. Michael D. Martin, et al., “Reconstructing Genome Evolution in Historic Samples of the Irish Potato Famine Pathogen,” Nature Communications 4, 2172, doi:10.1038/ncomms3172.

19. The results here are a bit complex. What has been found in Mexico and Ecuador is a close, close relative of the late blight that existed in 1845 in Ireland. The analyses Martin and his colleagues have done suggest that in the fields of Latin America, an even closer relative may still lurk. This relative would be the potato blight’s missing link, at least as far as the famine is concerned. It may be extinct; more likely it lives among the tens of thousands of traditional potato fields in Latin America, out there with the great diversity of potatoes and traditional knowledge, all of it largely ignored.

20. Michael D. Martin, et al., “Persistence of the Mitochondrial Lineage Responsible for the Irish Potato Famine in Extant New World Phytophthora infestans,” Molecular Biology and Evolution (2014), doi:10.1093/molbev/msu086.

Chapter 4

1. Pierre Sylvestre, “Aspects agronomiques de la production du manioc à la Ferme d’Etat de Mantsumba (République Populaire du Congo)” (Paris: IRAT [Institut de Recherches Agronomiques Tropicales et des Cultures Vivrières], 1973); Howard Everest Hinton, “Lycaenid Pupae That Mimic Anthropoid Heads,” Journal of Entomology Series A 49, no. 1 (November 1974): 65–69.

2. Danièle Matile-Ferrero, e-mail message to author, February 2, 2016.

3. The capital of what is now the Republic of the Congo.

4. Danièle Matile-Ferrero, “Une cochenille nouvelle nuisible au Manioc en Afrique équatoriale, Phenacoccus manihoti n. sp. (Homoptera: Coccoidea: Pseudococcidae),” Annales de la Société entomologique de France 13 (1977): 145–52.

5. The observation was made by the Commonwealth Institute of Entomology, which suggested it to be a species of the genus Phenacoccus.

6. Five different species of mealybug and scale insects were sent, but the abundant one, the new plague, was the species that came to be named Phenacoccus manihoti.

7. The word manioc derives from the Tupi word for the crop—mani; the word cassava comes from its Arawak equivalent. Because cassava was farmed throughout the tropical Americas, words for it exist in basically all the languages of the region. The spread of cassava through the region can actually be traced based on the etymology of its various names. See Cecil H. Brown, et al., “The Paleobiolinguistics of Domesticated Manioc (Manihot esculenta),” Ethnobiology Letters 4 (2013): 61–70.

8. Randolph Barker and Paul Dorosh, The Changing Agricultural Economy of West and Central Africa: Implications for IITA, paper prepared for the IITA Program Strategy Planning Review (Ibadan, Nigeria: International Institute for Tropical Agriculture, 1986).

9. Most often, the leaves are brought as a gift of food. But a stem of cassava is also often taken from one place to another as an offering not of food for that day but rather of food that might be planted for the future: “Here, take my cassava, it is sweet.”

10. Researchers at a branch of ORSTOM, the Office de la recherche scientifique et technique d’outre-mer, or the French Office of Technical Research Overseas (now the IRD, or the Institut de recherche pour le développement), would go on to document in great detail the biology of the various native parasites and predators in the Congo basin able to eat the mealybug. See Gérard Fabres and Danièle Matile-Ferrero, “Les entomophages inféodés à la cochenille du manioc, Phenacoccus manihoti (Hom. Coccoidea Pseudococcidae) en République Populaire du Congo: I. Les composantes de l’entomocoenose et leurs inter-relations,” Annales de la Société Entomologique de France 16, no. 4 (1980): 509–15.

11. These were the emissaries of the Swiss version of the Green Revolution, coming to spread “the word.”

12. Robert van den Bosch, The Pesticide Conspiracy (Berkeley: University of California Press, 1989).

13. In some cases, defenses are lost because plants can no longer produce particular toxins. In other cases, the situation is more complex. Wild corn—teosinte—produces airborne chemicals (volatiles) when its leaves are damaged in order to attract predators that eat the herbivores that are in turn eating the maize. North American varieties of corn produce fewer of these volatiles and so are less able to recruit predators when they are needed. See Yolanda H. Chen, Rieta Gols, and Betty Benrey, “Crop Domestication and Its Impact on Naturally Selected Trophic Interactions,” Annual Review of Entomology 60 (January 2015): 35–58; see also Cesar Rodriguez-Saona, et al., “Tracing the History of Plant Traits Under Domestication in Cranberries: Potential Consequences on Anti-Herbivore Defences,” Journal of Experimental Botany 62, no. 8 (February 2011): 2633–44; and Amanda M. Dávila-Flores, Thomas J. DeWitt, and Julio S. Bernal, “Facilitated by Nature and Agriculture: Performance of a Specialist Herbivore Improves with Host-Plant Life History Evolution, Domestication, and Breeding,” Oecologia 173, no. 4 (December 2013): 1425–37.

14. It is even germane to human biology. The developed countries of the world are concentrated in cold regions, where agriculture is more difficult not because of some collective punishment but instead because, it has been contended, in these regions humans are able to escape more of their pathogens. It is hard to imagine any reason anyone would willingly live in Sweden, for example, if it were not for the luxury of not having to deal with malaria and dengue.

15. Petra Dark and Henry Gent, “Pests and Diseases of Prehistoric Crops: A Yield ‘Honeymoon’ for Early Grain Crops in Europe?,” Oxford Journal of Archaeology 20, no. 1 (February 2001): 59–78.

16. A related form of enemy release occurs in fields where we spray large quantities of pesticides. These pesticides allow the crops to grow without threat—until, that is, an herbivore evolves the ability to tolerate the pesticide. When this happens, our pesticide-sprayed crops face the same challenges as cassava, but worse. The problem is worse because as long as pesticides are being sprayed, no predators of these new pests can consume the pests, so the pests become the organisms experiencing enemy release. They have all the food they could ever need and nothing in the world to fear.

17. Biogeographers, the folks who study the distribution of species, have tended to ignore the study of species most relevant to humans. As a result, while very good data exist on, say, where a particular species of warbler is located as well as how abundant it is in each place, the data on crop pests and pathogens—even human pathogens, for that matter—are terrible. The best maps available for most pests and pathogens are at the country level and simply record whether a particular pathogen is present or absent. See Michael G. Just, et al., “Global Biogeographic Regions in a Human-Dominated World: The Case of Human Diseases,” Ecosphere 5, no. 11 (November 2014): 1–21.

18. In addition, Gurr found that whether or not a crop was grown in the British Commonwealth had an effect on the enemies present on it. The most reasonable explanation for this pattern is that after crops were spread by British colonists, the continued movement of crops from one part of the empire to another also tended to move the pests and pathogens affecting those crops.

19. Daniel P. Bebber, Timothy Holmes, and Sarah J. Gurr, “The Global Spread of Crop Pests and Pathogens,” Global Ecology and Biogeography 23, no. 12 (December 2014): 1398–1407.

20. Donald R. Strong Jr., Earl D. McCoy, and Jorge R. Rey, “Time and the Number of Herbivore Species: The Pests of Sugarcane,” Ecology 58, no. 1 (January 1977): 167–75; Donald R. Strong Jr., “Rapid Asymptotic Species Accumulation in Phytophagous Insect Communities: The Pests of Cacao,” Science 185 (September 20, 1974): 1064–66.

21. Strong Jr., et al. “Time and the Number of Herbivore Species.”

22. Strong Jr., “Rapid Asymptotic Species Accumulation.”

23. Barundeb Bannerjee, “An Analysis of the Effect of Latitude, Age, and Area on the Number of Arthropod Pest Species of Tea,” Journal of Applied Ecology 18, no. 2 (August 1981): 339–42.

Chapter 5

1. An elegance dwells in knowing that one can pull the pieces of nature apart and predict the result. Ecologists love such elegance, even if it requires abstraction from the muddy details of ordinary life. In this they are like physicists, whose laws all work only in ideal conditions that do not really ever exist. Among ecologists, a favorite example of a trophic cascade is a study in which Tiffany Knight at Washington University in Saint Louis considered eight ponds, four with fish, four without. The ponds were otherwise similar. In ponds with fish, the fish ate dragonfly larvae, which led to fewer adult dragonflies. When the adult dragonflies were rare, they ate fewer bees and other pollinators. With more pollinators, pollination of flowers alongside the pond was more effective. With more effective pollination, the flowers produced more seeds. Does this chain of events happen often in nature? No, or at least not very often, yet it is a simplified illustration of the laws of nature that operate everywhere.

2. By the very most conservative estimates, three out of every four insect species on earth are not named. The situation is worse for fungal species, worse yet for bacteria, and when it comes to viruses, we can’t even really guess. As a result, most of the species living in tropical farms, be they cassava, coffee, or chocolate farms, are not yet named, nor is it known whether they are dangerous to those crops, dangerous to humans, or incredibly beneficial. Pest and pathogen species are better known than most species yet ultimately still far from completely understood.

3. In fact another species—another unnamed species, a mite—had begun to kill cassava in East Africa at around the same time.

4. Several years earlier researchers from the biological control unit of the Centre for Agriculture and Biosciences International (CABI) discovered a new mealybug in several countries in the eastern part of the Guyanas. The CABI team included a mealybug expert, D. J. Williams, who thought it was probably the same mealybug that was killing cassava in Africa. But whereas the mealybug on cassava in Africa was pink, this mealybug was yellowish. And whereas the mealybug in Africa reproduced sexually, this mealybug reproduced clonally, via parthenogenesis. The CABI team proceeded to try to release the pests and pathogens that attack this and another mealybug in Africa. But they were unable to get the parasites and pathogens to breed on the cassava mealybug in an insectary in the Congo. This was because, they would later learn, they were working on the wrong mealybug. Herren, who did not yet know any of this complex story, sent specimens to D. J. Williams and Jennifer M. Cox. With Herren’s specimens in hand Williams and Cox realized that what Herren had collected was the same mealybug they had seen in the Guyanas (and that had also been seen in Brazil).

5. Jennifer M. Cox and D. J. Williams, “An Account of Cassava Mealybugs (Hemiptera: Pseudococcidae) with a Description of a New Species,” Bulletin of Entomological Research 71, no. 2 (June 1981): 247–58. P. herreni would soon itself become a problem in Colombia and Venezuela, where its presence is associated with 80 percent crop losses. The story of this species and its emergence has yet to really be understood.

6. It is noteworthy that the mealybugs, while new to the scientists in Paraguay and Bolivia, were not new to the local farmers, who were able to tell the scientists when the mealybugs tend to attack, explain that their abundance varies seasonally, and identify the climatic conditions that tend to make them worse.

7. Hans R. Herren and Peter Neuenschwander, “Biological Control of Cassava Pests in Africa,” Annual Review of Entomology 36 (January 1991), 257–83.

8. Lopez’s wasp was first discovered in Argentina years earlier. What it feeds on in Argentina… well, no one has studied that.

9. If you feel sympathy with the mealybug and worry about its fate, perhaps it is comforting to know that hyperparasitoids of the genus Prochiloneurus lay their eggs in the bodies of the wasps inside mealybugs. Nature’s justice is layered.

10. G. J. Kerrich, “Further Systematic Studies on Tetracnemine Encyrtidae (Hym., Chalcidoidea) Including a Revision of the Genus Apoanagyrus Compere,” Journal of Natural History 16, no. 3 (1982): 399–430. The species was later transferred to the genus Anagyrus. The insects were checked only to see whether they infect honeybees or silkworms.

11. Anna Burns, et al., “Cassava: The Drought, War, and Famine Crop in a Changing World,” Sustainability 2, no. 11 (November 2010): 3572–3607; Andy Jarvis, et al., “Is Cassava the Answer to African Climate Change Adaptation?,” Tropical Plant Biology 5, no. 1 (March 2012): 9–29.

12. Interestingly, the diversity is unlikely to get much greater. Crop varieties—such as cassava, potatoes, bananas, and many figs—that are mostly propagated vegetatively (as clones) never get more diverse unless they occasionally get the chance to have sex. In potatoes, it seems that sex occurs—though it has not been well studied—via bumblebees. In their native range, many bananas are pollinated by fruit bats. In their native ranges, most figs are pollinated by wasps. But when these crops move, their chances to have sex decline because their pollinators (fig wasps and fruit bats) are left behind. In addition, in their new homes, the wild plants with which these plants might breed (the crops’ wild relatives) are less likely to be present. In some cases, as with figs and bananas, the ability to have sex at all is lost, the necessary genes broken beyond repair through disuse. In the case of cassava, little is understood about pollination in the wild. Cassava plants growing near their wild relatives clearly exchange genes with those relatives, but even questions as simple as which animals are carrying the pollen back and forth are unresolved. See Kenneth M. Olsen and Barbara A. Schaal, “Insights on the Evolution of a Vegetatively Propagated Crop Species,” Molecular Ecology 16, no. 14 (2007): 2838–40, and Marianne Elias and Doyle McKey, “The Unmanaged Reproductive Ecology of Domesticated Plants in Traditional Agroecosystems: An Example Involving Cassava and a Call for Data,” Acta Oecologica 21, no. 3 (2000): 223–30.

13. K. M. Lema and Hans R. Herren, “Release and Establishment in Nigeria of Epidinocarsis lopezi, a Parasitoid of the Cassava Mealybug, Phenacoccus manihoti,” Entomologia Experimentalis et Applicata 38, no. 2 (July 1985): 171–75.

14. Much of the hard work of the releases was done by Peter Neuenschwander, Herren’s longtime coconspirator in biological control.

15. Herren and Neuenschwander, “Biological Control of Cassava Pests in Africa.”

16. Ibid.

17. Although Herren could not have known it, he got lucky in his choice of parasitoid. Or maybe it is better to say that he got lucky in choosing a parasitoid incredibly well suited to the challenge at hand. He did not have the funds necessary to take the parasitoid from field to field across Africa. He would have to depend, to some extent, on the ability of the parasitoid to find cassava plants. But it could go one better than that, as Bellotti and his colleagues would later show. Or maybe it is more accurate to say that together with the cassava plants, it could go one better than that. Cassava plants, when damaged, release signaling compounds. The parasitoid Herren released is attracted to those compounds. In essence, the cassava signals, “I’m hurt by mealybugs,” and the parasitoids know where to look. Thanks to this signaling, the parasitoids spread quickly, from damaged plant to damaged plant across Africa, responding to signals in the air—signals few dreamed could exist, much less be able to permeate the dust-drunk plains.

18. Richard B. Norgaard, “The Biological Control of Cassava Mealybug in Africa,” American Journal of Agricultural Economics 70, no. 2 (May 1988): 366–71.

19. Peter Neuenschwander, “Biological Control of Cassava and Mango Mealybugs in Africa,” in Biological Control in IPM Systems in Africa, ed. Peter Neuenschwander, Christian Borgemeister, and Jürgen Langewald (Wallingford, UK: CABI Publishing, 2003), 45–59.

20. Ker Than, “Parasitic Wasp Swarm Unleashed to Fight Pests,” National Geographic, July 19, 2010, at http://news.nationalgeographic.com/news/2010/07/100719-parasites-wasps-bugs-cassava-thailand-science-environment/.

21. An article about Matile-Ferrero’s (still active) career notes that no one has been hired to replace her now that she has retired. Nor, the article notes, is anyone in charge of the group of insects Matile-Ferrero works on (which includes not only mealybugs but also scale insects, aphids, and whiteflies) at the major collections in Paris, London, the United States National Entomological Collection (in Maryland), and the Bohart Museum of Entomology at the University of California, Davis. Matile-Ferrero herself suggests that there is a good network of younger people trained in her field (coccidology), but whether they are able to find long-term work is probably an open question.

Chapter 6

1. CEPLAC was founded in 1957 as a “temporary commission.”

2. Marcellus M. Caldas and Stephen Perz, “Agro-Terrorism? The Causes and Consequences of the Appearance of Witch’s Broom Disease in Cocoa Plantations of Southern Bahia, Brazil,” Geoforum 47 (June 2013): 147–57.

3. It also helped usher in a style of cacao farming that, although more productive in terms of the quantity of cacao produced per acre (nearly double), was far more negative than positive in its effects on the environment. In addition, this style of farming made the cacao more susceptible to pests and most pathogens than it had been before.

4. Though, as it turns out, things are not quite so simple.

5. Harry Evans reports that the town of Vinces, Ecuador, even has a small, derelict Eiffel Tower. Here was, the message seemed to be, an Ecuadorian Paris.

6. Elizabeth Keithan, “Cacao Industry of Brazil,” Economic Geography 15, no. 2 (April 1939): 195–204.

7. Before humans arrived in the Americas, cacao and its relatives were dispersed by monkeys, as is still the case for wild cacao pods not collected by humans. Giant sloths and gomphotheres (extinct kin to the elephant) may also have dispersed the seeds along with some of the pathogens. See Paulo R. Guimarães Jr., Mauro Galetti, and Pedro Jordano, “Seed Dispersal Anachronisms: Rethinking the Fruits Extinct Megafauna Ate,” PLoS One 3, no. 3 (March 2008): e1745.

8. In the early years of cacao production in Bahia, many of those who grew Amelonado cacao were small farmers, including many who immigrated to the region. But with time, and given the high demand, cacao production became an endeavor carried out by a few relatively affluent “colonels.” In the succeeding decades and centuries, demand for cacao on the global market waxed and waned, but inevitably with less consequence for the colonels than for the owners of small farms or for the poor people who worked for the colonels. When the price dropped, the owners tended to fire their employees and leave cacao unpicked, in pods, growing like tumors from their trees’ trunks. When the prices rose, they hired and again and had every last pod, and every last bean within them, picked. These boom-and-bust cycles reinforced and exacerbated income inequalities in the region. See Keith Alger and Marcellus Caldas, “The Declining Cocoa Economy and the Atlantic Forest of Southern Bahia, Brazil: Conservation Attitudes of Cocoa Planters,” Environmentalist 14, no. 2 (1994): 107–19, and Caldas and Perz, “Agro-terrorism?”.

9. Fungi and plants are far more closely related than bacteria and plants or viruses and plants, so many things that kill a fungus harm the host as well.

10. H. Laker and S. A. Rudgard, “A Review of the Research on Chemical Control of Witches’ Broom Disease of Cocoa,” Cocoa Growers’ Bulletin 42 (1989): 12–24.

11. L. H. Purdy and R. A. Schmidt, “Status of Cacao Witches’ Broom: Biology, Epidemiology, and Management,” Annual Review of Phytopathology 34, no. 1 (February 1996): 573–94.

12. Fortunately, an international group had already been charged with helping develop approaches to control witches’-broom. Unfortunately, that group had noted, “If this disease were ever to hit Bahia’s cacao area, [the production of cacao] would decline severely. This… might well cause the global market to explode.” See Managing Witches’ Broom Disease of Cocoa (Brussels: International Office of Cocoa and Chocolate, 1984).

13. Traditionally, Amazonians consumed the fruit of the cacao pod rather than the seeds. It was only once cacao was domesticated and moved to Mesoamerica that the seeds began to be consumed. Most of the size and weight of the cacao seed is attributable to the two small leaves inside the seed that will grow once it germinates, the cotyledons. These cotyledons are full of fat, which they will use during germination. Fat is the best way to store a lot of energy in a small space, which is what the seeds need to do if they are going to grow on the forest floor, where sunlight is scarce. It is this fat, along with all the nutrients stored up in the leaves for defense and other roles, that gives the chocolate its lovely flavors. Other flavors come from the fermentation of the beans that occurs on the ground where they are grown. The beans yield all the products you can find in a chocolate bar. Cocoa butter is produced by squeezing the seed of the chocolate so that the fat drips out. Cocoa powder is what you get when you grind up the beans that have had the cocoa butter squished out of them. Chocolate (also called cocoa liquor) is produced by roasting the beans and grinding them up.

14. Nor is it yet known how witches’-broom causes disease. We know that the lineage that includes witches’-broom is composed primarily of species that are able to break down only dead plant materials. It also appears that the species of fungus associated with witches’-broom has acquired genes that allow it to better degrade living tissue (it stole them from a species of Phytophthora oomycete). But some argue that the fungus thought to cause the disease is, even with these genes, not sufficient to trigger all the symptoms of the disease when inoculated into plants. Instead, witches’-broom may be caused by the infection of the fungi along with another organism that rides with the fungi into the plant—a virus, perhaps.

15. See J. L. Pereira, L. C. C. De Almeida, and S. M. Santos, “Witches’ Broom Disease of Cocoa in Bahia: Attempts at Eradication and Containment,” Crop Protection 15, no. 8 (December 1996): 743–52.

16. The knot is described in the documentary The Knot: Deliberate Human Act (O nó: Ata humano deliberado), directed by Dilson Araújo: https://www.youtube.com/watch?v=_0mPiYocm-4#t=716&hd=1.

17. The cacao plantations of Bahia were within the region that was once the Atlantic Forest of Brazil. When the first Europeans landed in Brazil, this covered an area no smaller than half a million square miles, an area twice the size of France filled with species found nowhere else on earth. Today, as a result of agriculture, logging, human population expansion, and other pressures, just fifteen hundred square miles remain. The loss of nearly all this once great forest has been called one of the greatest biological tragedies of our time. The remaining patches of trees are home to tens of thousands (and perhaps hundreds of thousands) of bird, mammal, plant, and insect species that are found nowhere else. The traditional plantations in Bahia provided corridors among patches of forest through which animals could move as well as forests and habitats in their own right—thousands of square miles of forest canopy in a region where every patch matters. As forests, traditional cacao plantations helped conserve tens, perhaps hundreds, of thousands of species.

18. Where the definition of agricultural terrorism is construed broadly as “the intentional use, by any human agent other than uniformed military personnel, of organisms (or their products) to cause harm (or death) to humans, animals, or plants.” See Laurence V. Madden and Mark L. Wheelis, “The Threat of Plant Pathogens as Weapons Against US Crops,” Annual Review of Phytopathology 41, no. 1 (September 2003): 155–76.

19. Neil M. Ferguson, Christi A. Donnelly, and Roy M. Anderson, “Transmission Intensity and Impact of Control Policies on the Foot and Mouth Epidemic in Great Britain,” Nature 413 (October 2001), 542–48.

20. Described in the documentary The Knot.

21. Ibid.

22. Perhaps the only thing, some Brazilians began to suggest, that would save Brazilian cacao was if witches’-broom arrived in West Africa, making all the world’s cacao sick and, however horribly, evening the playing field. It was only a matter of time, some said, almost as a threat.

23. By his own account, though he has little reason to lie. He is a free, unindicted man, confessing guilt and, in so doing, putting himself at potential risk both legally and from anyone who suffered the fall of cacao and wanted to exact retribution.

24. As early as 1991, long before Timóteo came forward, some suspected the involvement of the Workers’ Party in the spread of witches’-broom, but at the time the accusation was little more than speculation.

25. The forest on the border with Bolivia had been cut under the orders of former president General Emílio Médici, who wanted the Amazon cleared for agriculture. He also had the Trans-Amazonian Highway constructed, along which cacao was to be a key crop. The aim for cacao was that its production would more than double in Brazil and that more than half of all production would come from the Amazon plantations. Yet the supposedly resistant varieties of cacao (resistant, at least, when grown in Trinidad) that were planted quickly became overcome with witches’-broom, and the plantations suffered losses of up to 90 percent. Had that forest not been cut, had those misguided plantations not been planted, it would have been much harder to move the witches’-broom.

26. Article 109, item IV, of the criminal code.

Chapter 7

1. As much as 70 percent of all cacao in the world comes from either Ivory Coast or Ghana, but cacao is grown in more than fifty countries, where it provides income for more than forty million people.

2. Adrian Frank Posnette was his birth name, but he was known as Peter by all those who worked with him.

3. The new imports could have brought witches’-broom with them, but fortunately none did. Care had been taken to quarantine the imports at the Royal Botanic Gardens, Kew, and then at the University of Reading, an effort similar to the quarantine for the parasites and pathogens affecting the cassava mealybug.

4. Girolamo Benzoni, an Italian traveling on the ships of Spanish conquistadors, wrote in 1556 that “cocoa flourishes only in a hot climate, in shaded locations; if it were exposed to the sun it would die.” Benzoni saw cacao being planted in low densities beneath rain-forest trees. The cacao trees in these traditional systems yield “shade chocolate,” much as coffee plants farmed in similar conditions yield “shade coffee.”

5. Diane W. Davidson, et al., “Explaining the Abundance of Ants in Lowland Tropical Rainforest Canopies,” Science 300, no. 5621 (2003): 969–72.

6. These entomologists included Dennis Leston, from Imperial College; Jonathan Majer, who would go on to study the ants of Australia; and Barry Bolton, who produced the catalog used by entomologists to look up the names of the world’s ants.

7. This led to a series of papers, the first of which was “Thermophilous Fungi of Coal Spoil Tips: I. Taxonomy,” Transactions of the British Mycological Society 57, no. 2 (October 1971): 241–54. The second was “Thermophilous Fungi of Coal Spoil Tips: II. Occurrence, Distribution, and Temperature Relationships,” Transactions of the British Mycological Society 57, no. 2 (October 1971): 255–66.

8. Harold Charles Evans and Dennis Leston, “A Ponerine Ant (Hym., Formicidae) Associated with Homoptera on Cocoa in Ghana,” Bulletin of Entomological Research 61, no. 2 (November 1971): 357–62.

9. On the genera Camponotus and Crematogaster, see Harold Charles Evans, “Transmission of Phytophthora Pod Rot of Cocoa by Invertebrates,” Nature 232 (July 1971): 346–47.

10. There now appear to be several species of Phytophthora black pod oomycetes infecting cacao, two in different regions of West Africa and another in the Americas. It is likely that more species will be found in the future, both as the pathogen is better studied and as new varieties and species make the jump from native forest plants onto cacao. Viruses that infect (and attack) these oomycetes are now being sought, but even once they are found, other viruses are likely to be needed to control the various species of Phytophthora. See Harold Charles Evans, “Cacao Diseases—The Trilogy Revisited,” Phytopathology 97, no. 12 (December 2007): 1640–43; and Harold Charles Evans, “Invertebrate Vectors of Phytophthora palmivora, Causing Black Pod Disease of Cocoa in Ghana,” Annals of Applied Biology 75, no. 3 (December 1973): 331–45.

11. Because these fungi evolved to manipulate the immune systems of insects (in order to prevent themselves from being attacked), they have proved useful in a variety of medical contexts. The drug cyclosporine, for example, used to suppress human immune systems for organ transplants, comes from one of these fungi.

12. The fungi invade the living bodies of ants and fill them with fungal cells. Once established in the ants, the fungi stimulate their hosts to leave their nest. The fungi then wait for the ants to arrive at a place that, from the fungus’s perspective, is just right—not too dry, not too wet, not too hot, not too cold. Once there, the fungi destroy the muscles that hold the mandibles of the ants open. In most species of ants, holding mandibles open takes energy, whereas snapping them shut does not. As a result, once their muscles are destroyed, the ants bite down into whatever they are standing on, which if things work out well for the fungi is a leaf of some sort. There the fungus grows a stalk up into the air and releases spores. Scientists interested in the basic functioning of the world have studied these fungi for a century to understand their strange ways. To these scientists, including Hughes, the fungi are beautiful manifestations of the elaborateness of nature—its wickedness, too. They are just one example of the many ways parasites can control the behavior of their hosts in order to benefit themselves. To cite another example, hairworms cause crickets and other insects to dive (fatally) into water. The hairworm needs to get into water to mate. The parasite Toxoplasma causes rats and mice to be attracted to the smell of cat urine, thereby increasing the odds that they are eaten. (It also, we now know, has a similar effect on chimpanzees, causing them to be attracted to the smell of leopard urine.) Toxoplasma can only successfully have sex inside a cat.

13. Around every corner in the story of West African cacao are more mysteries. The many varieties of cacao swollen shoot virus suggest that the virus colonized cacao from multiple hosts, though just which hosts, and how frequently, is not yet clear. The varieties of mealybugs that transmit these viruses have changed through time; the mealybug that used to transmit the virus is now rare. Just why is unclear. Climate change has been suggested, though not studied, as a possible cause. No fewer than a dozen mealybug species, and likely several unnamed mealybug species, now transmit the virus.

14. Dennis Leston, “The Ant Mosaic—Tropical Tree Crops and the Limiting of Pests and Diseases,” Pest Articles & News Summaries 19, no. 3 (1973): 311–41.

15. Similarly, the broad-scale fungicides that kill oomycetes are also likely to kill beneficial root fungi and leaf endophytes, particularly when the fungicides are sprayed from the ground up, toward the tops of tall cacao trees.

16. These practices are often described as backward or simple in comparison to larger, more intensive cacao plantations. Or at least that is how they are described, again and again, until pests and pathogens arrive.

Chapter 8

1. After first attending the Moscow Commercial Institute, per his father’s wishes, and graduating in 1906.

2. It was to be published Russian just five years later, in 1864.

3. Quoted in Igor G. Loskutov, Vavilov and His Institute: A History of the World Collection of Plant Genetic Resources in Russia (Rome, Italy: International Plant Genetic Resources Institute, 1999).

4. The seminar, entitled “Genetics and Its Linkage with Agronomy,” was one of several he gave as part of the Golytsin Higher Agricultural Courses for Women. In it he discussed genetics, the value of pure (inbred) lines in breeding, mutations, and the potential for using the theory of genetics in the practice of crop breeding. See Loskutov, Vavilov and His Institute.

5. Vavilov would go on to show that it was actually a new species of wheat, which he named Triticum persicum.

6. Throughout his decades of travel, Vavilov would never be without his fedora. No matter if he was hiking in mountains, deserts, or jungles. No matter if he was fleeing crocodiles or bandits. No matter if he was trapped in a tent with snakes. Vavilov would not be seen without his suit, a well-tied tie, and his perfectly placed hat.

7. Vavilov had seen similar symptoms in farmers after they ate bread in his earlier travels on Persia’s northern border and knew their cause. See Peter Pringle, The Murder of Nikolai Vavilov: The Story of Stalin’s Persecution of One of the Great Scientists of the Twentieth Century (New York: Simon and Schuster, 2008).

8. Such similarity was not a matter of chance; it had evolved in response to the advantages conferred on any crop able to persuade a farmer to unwittingly plant it along with his chosen seeds. Vavilov would be the first to study this kind of mimicry, which has since proved to be very common. Any weed that can mimic a crop seed has the potential to get planted by farmers in field after field: natural selection strongly favors very good mimics.

The first step in such mimicry is often crude—the evolution of a larger seed size (which makes seeds more likely to end up on the right side of the sieve as they are sorted). But such mimicry can also be extreme. The plant false flax (Camelina sativa) has even evolved into two different varieties, one a mimic of the oilseed variety of flax, another of the variety of flax used in making textiles. In some cases, these mimics become, over time, domesticated themselves. The oilseed version of false flax, for example, is a minor crop. More significantly, rye appears to have originally been a mimic of wheat. It grew among its stems and was only later (and perhaps begrudgingly) domesticated, an insight Vavilov formed on his 1916 expedition. He developed this hypothesis based on his observation that as he went up in elevation during his travels, fields of winter wheat were increasingly contaminated with ancient-seeming varieties of rye.

Often mimics become agricultural plants that grow in extreme conditions, as is the case with sand oat, which grows on sandier soil than does any true oat.

9. Perhaps he used a technique that has effectively led to the escape of many field biologists from border guards around the world: talking at length about the plants he collected and, in doing so, boring the detector into exhaustion.

10. See more about the story of this wheat variety in Gary Paul Nabhan, Where Our Food Comes From: Retracing Nikolay Vavilov’s Quest to End Famine (Washington, DC: Island Press, 2008).

11. Translation from Loskutov, Vavilov and His Institute.

12. By then also beginning to be known as the Department of Applied Botany and Plant Breeding.

13. Loskutov, Vavilov and His Institute.

14. Especially the work of the great Swiss biogeographer Alphonse de Candolle, e.g., Origin of Cultivated Plants (New York: D. Appleton, 1885).

15. In Nikolai Ivanovich Vavilov, Origin and Geography of Cultivated Plants, trans. Doris Love (Cambridge, UK: Cambridge University Press, 1992).

16. For a better sense of Vavilov’s journeys, Gary Nabhan’s book Where Our Food Comes From is a must-read. Nabhan visits many of the places Vavilov went and, in doing so, considers how traditional knowledge and the use of crop varieties have changed since Vavilov’s time. Much, Nabhan concludes, has been lost in many regions, but much also remains, the persistent flowering of cultures and their seeds.

17. The Bureau of Applied Botany already had a long history of seed collection, crop breeding, and agricultural research in general. The focus of the bureau, however, was on the Russian Empire, which given Russia’s geographic dimensions was nonetheless an ambitious mandate. By 1914, the collection already included some fourteen thousand seed accessions (collections) from across Russia and beyond. For an excellent review of this history, see Loskutov, Vavilov and His Institute.

18. He said this before dismissing the reporter with “Apologies, monsieur, life is short, time has no patience” (Pringle, The Murder of Nikolai Vavilov, 188).

19. Estimate from Nabhan, Where Our Food Comes From.

Chapter 9

1. Carl-Gustav Thornstrom and Uwe Hossfeld, “Instant Appropriation—Heinz Brücher and the SS Botanical Collecting Commando to Russia 1943,” Plant Genetic Resources Newsletter 129 (2002): 39.

2. He wrote, “The climatic conditions of these eastern areas place very special demands on cultivated plants.… Falling back on the primitive origins of the cultivated plants that Vavilov collected is all the more important in the current state of plant genetics.” As the writer Noel Kingsbury points out, the Nazis were also interested in new plant varieties. These included homeopathic herbs and a potential substitute for rubber, the dandelion Taraxacum kok-saghyz. These new crops were often grown in nurseries in concentration camps. See Noel Kingsbury, Hybrid: The History and Science of Plant Breeding (Chicago: University of Chicago Press, 2009).

3. One of many tragic ironies was that Vavilov had been arrested not so many years before, in Mexico, and accused of the opposite—stealing seeds for the Russian government to the detriment of other countries, including Mexico and the United States. See Gary Paul Nabhan, Where Our Food Comes From: Retracing Nikolay Vavilov’s Quest to End Famine (Washington, DC: Island Press, 2008).

4. Gary Paul Nabhan puts it plainly enough when he says, “Lysenkoism dragged Soviet biologists and agronomists into the murky backwaters of the life sciences until Lysenko’s shoddy experiments and ideological rants were discredited by an overwhelming outcry from other Soviet scientists in 1964.” See Nabhan, Where Our Food Comes From.

5. Mark Popovsky, The Vavilov Affair (Hamden, CT: Archon Books, 1984).

6. Meanwhile, the two friends whom Vavilov had falsely accused of being “agricultural spies”—one of whom Vavilov had encouraged to return to Russia, despite the man’s being happily settled in the United States—were executed.

7. Kasha (Fagopyrum esculentum), Vavilov would have noted, is also called buckwheat. It is not, however, a wheat at all, or even a grass, but rather a kind of sorrel. It was domesticated somewhere in Asia and during Vavilov’s life became an important Russian crop.

8. Kingsbury, Hybrid.

9. Nabhan, Where Our Food Comes From.

10. Calvin O. Qualset, “Jack R. Harlan (1917–1988): Plant Explorer, Archaeobotanist, Geneticist, and Plant Breeder,” in The Origins of Agriculture and Crop Domestication: The Harlan Symposium, ed. A. B. Damania, et al. (Aleppo, Syria: 1997).

Chapter 10

1. Minnesota was at the time probably the world leader in the study of wheat. John Perkins argues that this preeminence is in part attributable to the role of the state in the milling and baking of wheat growing on the Great Plains. See John H. Perkins, Geopolitics and the Green Revolution: Wheat, Genes, and the Cold War (Oxford, UK: Oxford University Press, 1997).

2. In 1953, a strain of stem rust (15B) would destroy 80 percent of the durum wheat growing in the United States.

3. Stakman was called to Mexico by Henry Wallace, Franklin Delano Roosevelt’s vice president. Wallace had recently visited Mexico and had been struck by the need for the improvement of crops, particularly corn and wheat. Wallace had several reasons to hope for such improvement. For one, he really appears to have believed it was the right thing to do, a just and important cause. For another, stabilizing the agriculture of Mexico was seen to be vital in the fight against Communism (poverty and instability, it was said, bred Communism). Finally, Wallace was the president of Pioneer Hi-Bred, the company that had brought new hybrid corn varieties to North America. The company could serve as a model for the next steps in Mexico and maybe even derive some benefit for itself. For all these reasons, Wallace persuaded the Rockefeller Foundation to bring a team to Mexico; it was the Rockefeller Foundation that contacted Stakman.

4. Those who worked with Borlaug in Mexico note that he expected the same of everyone who worked with him. To work with Borlaug was like joining the Peace Corps and the Marines at the same time, said Jesse Dubin in an interview with Susan Dworkin. The only difference was that the entire focus was on wheat, and the enemy was either rust or, more often, inefficiency—inefficiency in work and inefficiency in how much food the wheat could produce from sunlight, irrigation, and fertilizer. At night the men relaxed by drinking and talking about wheat. Then they woke up and worked on wheat. See Susan Dworkin, The Viking in the Wheat Field: A Scientist’s Struggle to Preserve the World’s Harvest (New York: Walker Books, 2009), 239.

5. This was to be the precursor to the International Maize and Wheat Improvement Center, CIMMYT (or Centro Internacional de Mejoramiento de Maíz y Trigo). Agricultural history is full of acronyms. CIMMYT would be the center through which US scientists worked with Mexican scientists to breed new varieties of wheat and corn. In time, it would become part of a consortium of centers, each with its own acronym, carrying out similar missions in other regions of the world, including the International Rice Research Institute, in the Philippines (IRRI); the International Potato Center, in Peru, which I have already mentioned (CIP, or Centro Internacional de la Papa); the International Center for Tropical Agriculture, in Colombia (CIAT, or Centro Internacional de Agricultura Tropical), where Tony Bellotti worked when tracking down the cassava mealybug; the International Institute of Tropical Agriculture (IITA), where Hans Herren worked; and the International Center for Agricultural Research in the Dry Areas (ICARDA), to which we will turn later. The group to which these institutes all belong is the Consultative Group for International Agricultural Research (CGIAR), originally funded by the World Bank, the Food and Agriculture Organization (FAO), and the United Nations Development Programme (UNDP). Then, of course, there is also CABI, the Centre for Agriculture and Biosciences International, which has played a major role in many aspects of crop protection. I’ve tried to avoid using these acronyms where I have been able to, but if you’re ever at a party with the small group of people in the know, you will need to know them as well. Consider this endnote, then, to be your cheat sheet. And if you really want to seem as though you are in with the in crowd, don’t say “CGIAR”: use the short form of this acronym, “the CG system,” which frankly makes it sound like the sort of weight-loss product you might buy late at night after watching an infomercial.

6. The wheat varieties from Mexico that Borlaug used were developed by Mexican farmers from those brought over by Cortés and other Europeans in little more than five hundred years. They are a testament to the extraordinary ability of traditional farmers to create diversity from simplicity. In many ways, this was the opposite of what Borlaug was doing, with one exception: Borlaug saved not only the traditional varieties he collected but also the new varieties he made through his crosses. Together, the traditional and new varieties numbered around five thousand. Borlaug sent the seeds to the National Small Grains Collection, then as now the largest grain collection in the United States. There, the amazing grain—the diverse grain, the grain of Mesoamerican and Borlaugian ingenuity—was put in some boxes at room temperature and ignored. The seeds all germinated and rotted. There were no backups.

7. At one point Harrar simply told Borlaug he had to stop the work in Sonora. It wasn’t going to work. It was too expensive. It was too hard. Borlaug resigned. The next day, Harrar gave in and told Borlaug he could keep working in Sonora. The resignation was ignored.

8. Fertilizer would prove key to Borlaug’s vision for agriculture, and the industrial production of fertilizer was the result of war. Until World War I, nearly all fertilizer came from bird or bat guano. Then, during the war, scientists at the German company BASF (Badische Anilin und Soda Fabrik, or, in English, Baden Aniline and Soda Factory) were tasked with finding a way to produce more ammonia for bombs. The scientists developed a method we now call the Haber-Bosch process, which could be used to produce large quantities of ammonia industrially, which in turn was used in bombs during the war. After the war, BASF used the same approach—the same equipment, even—to produce more ammonia, which was then converted into fertilizer.

9. Norin 10 stood out because of how very short it was. But short wheats from Japan had been observed as early as 1873 by Horace Capron, who headed an American delegation to Japan and brought some of the wheats back to the United States. Similar wheat had previously been distributed from Japan to France. Later, other short wheats were shared between Japan and Italy. It is tempting to see the Americans as having unjustly taken Norin 10 from the Japanese, but it is worth noting that Norin 10 itself is the result of many earlier borrowings. The Japanese had crossed a variety of wheat called Fultz, obtained from the United States (where it had been taken from the Mediterranean), with a Japanese variety called Daruma. The result of this cross was then crossed with a variety of wheat that had been brought from Russia to Kansas by Mennonite immigrants. Norin 10 would ultimately result from further work that Inazuka did on the basis of this latter cross. The free sharing of varieties was key to Borlaug’s version of progress.

10. Perkins, Geopolitics and the Green Revolution.

11. The institute’s website (http://irri.org/about-us/our-history) offers a nice timetable of its history, along with historical videos of the work at the institute.

12. It is interesting to consider the ways in which various regions contribute to the world. Borlaug spread the Green Revolution around the globe and with it a new way of farming, eating, and living that is a key aspect of modern Western life, however one feels about it. As for the French, as a different sort of example, they offered the world the restaurant. The waiter, the napkins, the number of courses, that the last course is sweet, that the first course is small, that a specific kind of wine might go with a specific kind of food—that’s all French. Even the word restaurant refers to a sort of fortifying meat broth (with restorative powers) associated with the very venues where one might go out to eat, take a date, hint at romance, savor food—oh, really savor it—and savor, too, the conversation. In other words, Borlaug gave us sustenance, food to sustain us, and the French, they offered something else: tables and meals, and with them the restorative power of both flavors and conversations.

13. Many argue that it was this success that the funders, including the Ford Foundation, the Rockefeller Foundation, the US government, and the World Bank, were most eager to see happen. The new agriculture provided food and, it was thought, forestalled socialism at the same time. See Cary Fowler and Pat Mooney, Shattering: Food, Politics, and the Loss of Genetic Diversity (Tucson: University of Arizona Press, 1990).

Chapter 11

1. See Schultes’s own account, “The Domestication of the Rubber Tree: Economic and Sociological Implications,” American Journal of Economics and Sociology 52, no. 4 (October 1993): 479–85. See also Wade Davis’s brilliant biogeography of Schultes and his work, One River: Explorations and Discoveries in the Amazon Rain Forest (New York: Simon and Schuster, 1996). Yes, the seeds could be eaten, though only after a fair amount of work. Like cassava roots, the seeds of H. brasiliensis contain cyanide and so had to be soaked, boiled, and soaked again in order to be made palatable and safe.

2. Wickham, whose actions the modern world is greatly dependent upon, was a character. Before he gathered rubber seeds, he had first tried to make his name and fortune in Nicaragua by shooting birds in order to pluck their feathers, which he would then sell to his mother, who ran a millinery shop in London. He failed, in no small part because of the fact that he was not very good at shooting birds. See Joe Jackson, The Thief at the End of the World: Rubber, Power, and the Seeds of Empire (New York: Viking, 2008).

3. Joseph was the son of William Hooker, the former director of Kew. The father and son worked together for forty years and even inspired a book entitled The Hookers of Kew, which sold very well in the United States, perhaps because of a misunderstanding of the title.

4. Stuart McCook and John Vandermeer, “The Big Rust and the Red Queen: Long-Term Perspectives on Coffee Rust Research,” Phytopathology 105, no. 9 (September 2015): 1164–73.

5. Though interestingly, the biology of the trees and plantations still circumscribed the lives of the rubber tappers, even in Asia. Whereas in the Amazon a very busy tapper, working until he was nearly incapacitated each day, could tap eighty-five trees, in tropical Asian plantations a tapper could tap 350. Close planting made the travel easier, but each day was (and is) still composed of a circuit of very well known trees.

6. Which is to say that by 1921 Asia was producing ten times as much latex as was being produced in the Amazon during the peak years of extraction. Ten times.

7. Julian Street, Abroad at Home: American Ramblings, Observations, and Adventures of Julian Street (New York: Century Company, 1914).

8. Braz Tavares da Hora Júnior, et al., “Erasing the Past: A New Identity for the Damoclean Pathogen Causing South American Leaf Blight of Rubber,” PLoS One 9, no. 8 (August 2014): e104750. In this study, the authors rename the fungus but also note that it had been so poorly studied genetically that our knowledge of which other species it might be related to was ambiguous. Worse yet, our knowledge of which other species are really one and the same with it was also ambiguous. It was only through this very recent work that the life history of the fungus was fully resolved and that we realized this fungus’s close relation to other terrible plant pathogens, including the one that causes black Sigatoka, a disease affecting bananas.

9. At this point, several scientists had already warned of the dangers of leaf blight to rubber plantations, but apparently neither Ford nor those who worked with him read W. N. C. Belgrave, “Notes on the South American Leaf Disease of Rubber,” Journal of the Board of Agriculture of British Guiana 15 (1922): 132–38, or J. R. Weir, “The South American Leaf Blight and Disease Resistant Rubber,” Quarterly Journal of the Rubber Research Institute of Malaya 1 (1929): 91–97. Kids, this is why we have to publish in open-access journals.

10. It was around $20 million in 1940s dollars.

11. It was also a dream of Adolf Hitler. Hitler went so far as to announce in 1935, at the seventh Nazi party congress, in Nuremberg, that the Nazis had figured out how to produce synthetic rubber. Fortunately, he was lying.

12. The Americans not only saw the need to be able to produce their own rubber, they also saw the extent to which Europeans could be dependent on it. As a result, rubber production factories in both Germany and Italy were among the most important bombing targets during the war.

13. There are only eleven known species of Hevea, which is to say that Schultes was able to collect, on his personal expedition, all but one of the Hevea species known in the world. See Reinhard Lieberei, “South American Leaf Blight of the Rubber Tree (Hevea spp.): New Steps in Plant Domestication using Physiological Features and Molecular Markers,” Annals of Botany 100, no. 6 (December 2007), 1125–42, at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759241/pdf/mcm133.pdf.

14. As Wade Davis notes in his book One River: Explorations and Discoveries in the Amazon Rain Forest (New York, Simon and Schuster, 1996), a history of both rubber exploration and Schultes.

15. Davis, One River, 537.

16. Daniel C. Ilut, et al., “Genomic Diversity and Phylogenetic Relationships in the Genus Parthenium (Asteraceae),” Industrial Crops and Products 76 (2015): 920–29.

Chapter 12

1. Oghenekome Onokpise and Clifford Louime, “The Potential of the South American Leaf Blight as a Biological Agent,” Sustainability 4, no. 11 (November 2012): 3151–57, http://www.mdpi.com/2071-1050/4/11/3151.

2. Kheng Hoy Chee, “Management of South American Leaf Blight,” The Planter 56 (1980), 314–25.

3. One other solution, although we would need to start planning a decade or more before we would expect to see results, would be to plant rubber in those places where rubber trees grow but the blight cannot. In essence, the approach would be to move the rubber not so much geographically as climatically—to extreme climates. See Franck Rivano, et al., “Suitable Rubber Growing in Ecuador: An Approach to South American Leaf Blight,” Industrial Crops and Products 66 (April 2015): 262–70. Yet while this seems promising and appears to be working on a small scale in Guatemala, Ecuador, and parts of Brazil too extreme in climate for the blight, it would need to happen now in order to be able to save rubber in fifteen years. In addition, the odds that leaf blight would evolve to colonize new climates, if many rubber trees were there, seem high.

4. Hans ter Steege, et al., “Estimating the Global Conservation Status of More Than 15,000 Amazonian Tree Species,” Science Advances 1, no. 10 (November 2015): e1500936.

5. Even if more resistant trees are produced, if they do not yield as much latex as the trees planted in Asia, none is likely to be planted at any scale in Asia unless leaf blight arrives. At that point, any efforts to replant with resistant varieties on a large scale would take time (for trees to grow) and would require additional land in order to yield the same amount of rubber already being produced. In theory, the trees that have been planted experimentally in Brazil and elsewhere in the Americas might next be grown in greater numbers. New plantations like those Ford established might be grown. But when they are, they will be less productive than the plantations in Asia (and thus likely less profitable). In addition, farmers will deal with leaf blight as a certainty rather than a possibility. What’s more, as leaf blight has begun to be better studied (although still far less well than one might hope), it has been revealed to be both very diverse and rapidly evolving. In other words, many leaf blights exist, with varying abilities to deal with resistant trees. That some of these varieties of leaf blight might be able to destroy even the resistant trees is, well, possible.

6. Gary Paul Nabhan, Where Our Food Comes From: Retracing Nikolay Vavilov’s Quest to End Famine (Washington, DC: Island Press, 2008).

7. Francesco Emanuelli, et al., “Genetic Diversity and Population Structure Assessed by SSR and SNP Markers in a Large Germplasm Collection of Grape,” BMC Plant Biology 13 (2013): 39, at http://bmcplantbiol.biomedcentral.com/articles/10.1186/1471-2229-13-39. The challenge of our dependence upon the occasional reproduction of traditional varieties of crops and their wild relatives is that it is most likely to occur in the places where the traditional varieties of crops are hardest to farm—in their native ranges, where their pests and pathogens are most diverse. As a result, such farms have far greater value than what might be suggested by the cost of their products in the market. The value of traditional varieties of corn being farmed in Mexico, for example, is not only to local culture and conservation. It is also—because Mexico is one of relatively few places where the genes of wild teosinte might occasionally mix with those of traditional corn and produce new varieties—a boon to corn planted anywhere on earth. It benefits us all when we subsidize the farming of traditional varieties of crops in their native ranges, whether through government subsidies or the extra money we pay to buy such crops.

8. Squash bees are the main pollinator of squash plants, or at least they are in the places in which squash are native or were moved before the time of conquistadors. See Margarita M. López-Uribe, et al., “Crop Domestication Facilitated Rapid Geographical Expansion of a Specialist Pollinator, the Squash Bee Peponapis pruinosa,” Proceedings of the Royal Society B: Biological Sciences 283, no. 1833 (June 2016). We know relatively little about the pollination of the squash plants that have been moved on ships from the Americas to Africa and Asia. Similarly, little work has been done to understand how the relative of squash, the bottle gourd, is pollinated where it has been introduced. Or, for that matter, how cucumbers (distant kin to the squash) are pollinated in the Americas far from the pollinators with which they evolved. Our general tendency is to move our crops from place to place and hope that somehow these wonderful mutualists come along, or that their roles continue to be carried out by some local replacement, an ecological stand-in. Sometimes this works. Nature forgives some of our faults. In other cases, we figure out after many years of struggle that something quite important has been left behind.

9. Though it is worth noting that even resistance derived from a crop’s wild relatives is not permanent. Pests and pathogens continue to evolve. A strain of grassy stunt virus, for example, has been found to have evolved the ability to overcome the resistance to it bred from wild rice into domesticated rice.

10. Brian V. Ford-Lloyd, et al., “Crop Wild Relatives—Undervalued, Underutilized and Under Threat?,” BioScience 61, no. 7 (2011): 559–65.

11. Nigel Maxted, et al., “Toward the Systematic Conservation of Global Crop Wild Relative Diversity,” Crop Science 52, no. 2 (2012): 774–85.

12. Hallie Eakin, “Institutional Change, Climate Risk, and Rural Vulnerability: Cases from Central Mexico,” World Development 33, no. 11 (November 2005): 1923–38.

13. Tsutomu Ishimaru, et al., “A Genetic Resource for Early-Morning Flowering Trait of Wild Rice Oryza officinalis to Mitigate High Temperature-Induced Spikelet Sterility at Anthesis,” Annals of Botany 106 no. 3 (2010): 515–20. See also Hannes Dempewolf, et al., “Adapting Agriculture to Climate Change: A Global Initiative to Collect, Conserve, and Use Crop Wild Relatives,” Agroecology and Sustainable Food Systems 38, no. 4 (2014): 369–77.

14. Neil Brummitt and Steven Bachman, Plants Under Pressure: A Global Assessment—The First Report of the IUCN Sampled Red List Index for Plants (London: Royal Botanic Gardens, Kew, 2010). Also see Colin K. Khoury, et al., “An Inventory of Crop Wild Relatives of the United States,” Crop Science 53, no. 4 (2013): 1496–1508 for more about crop wild relatives in the specific context of the United States.

15. Cade Metz, “The Superplant That May Finally Topple the Rubber Monopoly,” Wired, July 13, 2015, at http://www.wired.com/2015/07/superplant-may-finally-topple-rubber-monopoly/.

16. Ibid.

17. The Aztecs used guayule to produce rubber. The word guayule derives from the Nahuatl word ulli, for “rubber”; the plant was one of two used by the Aztecs for rubber production. The rubber balls the Aztecs used in their sports may have been produced from guayule. Beginning in the early 1900s, the United States began to harvest guayule in Arizona and then imported it from Mexico for use in tires. It was gathered as a buffer against the worry that most of the supply of rubber had been monopolized by Asia. By 1910, roughly 10 percent of the rubber in the world came from guayule. But there was a problem. Wild populations of the plant were quickly disappearing. By 1911, perhaps as little as 20 percent of the populations of the plant present in 1890 in Mexico and the United States remained. Investors, including the Rockefeller Foundation, decided in the early 1900s (even before Ford dreamed of a Brazilian empire) to try to farm guayule to produce rubber. They invested $30 million in the project, which built upon attempts at the domestication of guayule that had begun in 1910. The attempt moved forward, but slowly. Then in the 1940s, during World War II, tens of thousands of acres were planted in guayule. The guayule grew, but not quickly enough. By the time things were starting to take off, the war ended, artificial rubber was invented, and the perceived need for an alternative rubber source evaporated.

18. Charles Darwin, On the Origin of Species by Means of Natural Selection: Or the Preservation of Favoured Races in the Struggle for Life, 4th ed. (London: John Murray, 1866).

19. For example, the wild rice Oryza rufipogon has been shown to support seven times as many species as domesticated rice, O. sativa. See Yolanda H. Chen, Rieta Gols, and Betty Benrey, “Crop Domestication and Its Impact on Naturally Selected Trophic Interactions,” Annual Review of Entomology 60 (January 2015): 35–58.

20. There are some exceptions to this generalization. War is full of exceptions, contradictions, caveats, and complexities, one of them being that in some cases the no-man’s-land between warring tribes, clans, or regions can be an area in which conservation occurs by default because of the relative absence of humans. The area, for example, in which Lewis and Clark saw bison in the greatest abundance appears to have been just such a no-man’s-land: the warring tribes were unwilling to enter that region. See Paul S. Martin and Christine R. Szuter, “War Zones and Game Sinks in Lewis and Clark’s West,” Conservation Biology 13, no. 1 (February 1999): 36–45. The same may be true for some crop wild relatives.

Chapter 13

1. The lesson I learned in this particular context was to never ask, “Hey, what’s in that jar on your shelf?”

2. Kristen Mack, “Leigh Van Valen, 1935–2010: Evolutionary Biologist Coined ‘Red Queen’ Theory of Extinction,” Chicago Tribune, October 24, 2010, at http://articles.chicagotribune.com/2010-10-24/features/ct-met-obit-van-valen-20101024_1_extinction-journals-modern-biology. Generally speaking, the word quirky is a euphemism for some better and more interesting but slightly offensive description.

3. Comparison from Matt Ridley, The Red Queen: Sex and the Evolution of Human Nature (London: Penguin Books, 1994). Though if we are going to get picky, Van Valen’s beard seems as though it was just about exactly the same length as that of Leonardo da Vinci.

4. For the interested and the bold, “Mating Behavior in the Dinosauria”: https://dl.dropboxusercontent.com/u/18310184/songs/dino-wedding.pdf.

5. Mack, “Leigh Van Valen.”

6. He was voted “most academic” in the second grade. In the second grade!

7. And he was rarely stultified. Van Valen once named, for example, twenty fossil mammals after characters in J. R. R. Tolkien’s fiction. See Douglas Martin, “Leigh van Valen, Evolution Revolutionary, Dies at 76,” New York Times, October 30, 2010, at http://www.nytimes.com/2010/10/31/us/31valen.html.

8. Leigh Van Valen, “A New Evolutionary Law,” Evolutionary Theory 1 (1973): 1–30. Evolutionary Theory would go on to be published sporadically for years and attracted to its editorial board some of the greatest luminaries of evolutionary biology.

9. John F. Tooker and Steven D. Frank, “Genotypically Diverse Cultivar Mixtures for Insect Pest Management and Increased Crop Yields,” Journal of Applied Ecology 49, no. 5 (October 2012): 974–85. Evidence also suggests that diversity of crop species in or adjacent to a field may also reduce crop loss in the first place, even before a shift is made from less to more resistant varieties. However, the extent of this benefit seems variable. See Deborah K. Letourneau, et al., “Does Plant Diversity Benefit Agroecosystems? A Synthetic Review,” Ecological Applications 21, no. 1 (January 2011): 9–21. Traditional farms also vary greatly, from culture to culture and region to region, in the ways in which crops are farmed. Most of this variation has been poorly studied, even more so than the seeds themselves. As a result, while the knowledge embedded in traditional farming systems around the world is potentially very useful as we think about the future of crops, is rapidly being lost.

10. Jelle Bruinsma, ed., World Agriculture: Towards 2015/2020: An FAO Perspective (Rome, Italy: Food and Agriculture Organization of the United Nations, 2003).

11. The consequences are predictable not only in general but also in many details (though nature doesn’t always perfectly heed predictions). For example, theory predicts that the more tropical the region in which one of these crops is planted, the more quickly resistance may evolve. This might occur for two reasons. First, the tropics are much more diverse than are temperate regions, so the number of insect, fungus, and oomycete species that land in fields and try to eat crops is much higher. In the lottery of species, having more species try to win and having them try to win more times per year pays off, at least for them. Second, in the tropics, generation times are faster, and so because biological stories are measured in generations, not years, time fast-forwards in proportion to the number of generations pests and pathogens produce per year. Though this second explanation does come with a caveat. If generations are very short in insects, they may fail to be exposed to kill them (and their populations hence suffer little selection). If generations are very long, all the insects in the population may die (and hence suffer no selection, since no individuals are left over to be favored). It may be that in these cases that organisms with intermediate generation times evolve most rapidly, as has been suggested for existing examples of resistance. See for example Rosenheim, Jay A., and Bruce E. Tabashnik. “Influence of generation time on the rate of response to selection.” American Naturalist (1991): 527–541.

12. Andrew J. Forgash, “History, Evolution, and Consequences of Insecticide Resistance,” Pesticide Biochemistry and Physiology 22, no. 2 (October 1984): 178–86.

13. University breeding programs and public breeding programs have been gutted in direct proportion to the success of the Green Revolution.

14. Youyong Zhu, et al., “Genetic Diversity and Disease Control in Rice,” Nature 406 (August 17, 2000): 718–22.

15. We are studying the microbes of household insects in my lab to see if they can turn paper waste into energy.

16. Bart Lambert and Marnix Peferoen, “Insecticidal Promise of Bacillus thuringiensis,” BioScience 42, no. 2 (February 1992): 112–22.

17. Richard J. Milner, “History of Bacillus thuringiensis,” Agriculture, Ecosystems & Environment 49, no. 1 (May 1994): 9–13.

18. Though it is worth nothing that these are the same minds, the same beautifully focused minds, about which one could easily write many comedic novels—beautiful minds peering deep into the mysteries of life but coming up only rarely to get a sense of context.

19. Tina Kyndt, et al., “The Genome of Cultivated Sweet Potato Contains Agrobacterium T-DNAs with Expressed Genes: An Example of a Naturally Transgenic Food Crop,” Proceedings of the National Academy of Sciences of the United States of America 112, no. 18 (May 5, 2015): 5844–49.

20. Though this is a gradient, not a set of categories. It is probably more sensible to talk about forms of genetic engineering imposed by humans on crops. At one extreme is the Native American farmer who chooses corn with sugary stalks over those with less sugary stalks, and in doing so engenders/creates/engineers a crop that has the genes associated with a sugary stalk. At the opposite extreme is the activity of engineering plants that produce human breast milk. Engineering a plant to produce a toxin it didn’t already produce is somewhere between these extremes.

Chapter 14

1. John Seabrook, “Sowing for Apocalypse: The Quest for a Global Seed Bank,” New Yorker, August 27, 2007.

2. Frances Moore Lappé and Joseph Collins with Cary Fowler, Food First: Beyond the Myth of Scarcity (Boston: Houghton Mifflin, 1977). Lappé was by then already well known as author of the bestselling Diet for a Small Planet, which advocated vegetarianism as an ecologically sustainable lifestyle.

3. Harlan was by no means the first to voice this argument. Erwin Baur, a German botanist, had already noticed the shift as early as 1914. See his “Die Bedeutung der primitiven Kulturrassen und der wilden Verwandten unserer Kulturpflanzen für die Pflanzenzüchtung” [The importance of the primitive cultivars and wild relatives of our crops for plant breeding], Jahrbuch der Deutschen Landwirtschafts Gesellschaft 29 (1914): 104–10.

4. Jack R. Harlan, “Genetics of Disaster,” Journal of Environmental Quality 1, no. 3 (July–September 1972): 212–15.

5. Jack Harlan was quick to credit others who had voiced similar sentiments before him, but because the man he gave the most credit to was Harry Harlan, his dad, who was a friend of Vavilov, we can still call this hypothesis Harlan’s ratchet while acknowledging some ambiguity as to which Harlan we are talking about.

6. Alfred W. Crosby Jr., The Columbian Exchange: Biological and Cultural Consequences of 1492 (Westport, CT: Praeger Publishers, 2003).

7. Cary Fowler and Pat Mooney, Shattering: Food, Politics, and the Loss of Genetic Diversity (Tucson: University of Arizona Press, 1990).

8. Seabrook, “Sowing for Apocalypse.”

9. This assumes that the genes for resistance are recessive. If they are dominant, the refuge strategy would still delay resistance, but not forever.

10. For a thoughtful review of what was and was not working in the first billion acres of Bt crops, see Bruce E. Tabashnik, Thierry Brévault, and Yves Carrière, “Insect Resistance to Bt Crops: Lessons from the First Billion Acres,” Nature Biotechnology 31, no. 6 (June 2013): 510–21.

11. Kong-Ming Wu, et al., “Suppression of Cotton Bollworm in Multiple Crops in China in Areas with Bt Toxin–Containing Cotton,” Science 321, no. 5896 (September 19, 2008): 1676–78; Janet E. Carpenter, “Peer-Reviewed Surveys Indicate Positive Impact of Commercialized GM Crops,” Nature Biotechnology 28 (2010): 319–21; William D. Hutchison, et al., “Areawide Suppression of European Corn Borer with Bt Maize Reaps Savings to Non-Bt Maize Growers,” Science 330, no. 6001 (October 8, 2010): 222–25; Michael D. Edgerton, et al., “Transgenic Insect Resistance Traits Increase Corn Yield and Yield Stability,” Nature Biotechnology 30 (2012): 493–96; Jonas Kathage and Matin Qaim, “Economic Impacts and Impact Dynamics of Bt (Bacillus thuringiensis) Cotton in India,” Proceedings of the National Academy of Sciences of the United States of America 109, no. 29 (July 17, 2012): 11652–56.

12. Yanhui Lu, et al., “Widespread Adoption of Bt Cotton and Insecticide Decrease Promotes Biocontrol Services,” Nature 487 (July 19, 2012): 362–65.

13. Bruce E. Tabashnik and Yves Carrière, “Successes and Failures of Transgenic Bt Crops: Global Patterns of Field-Evolved Resistance,” in Bt Resistance: Characterization and Strategies for GM Crops Producing Bacillus Thuringiensis Toxins, ed. Mario Soberon, Yulin Gao, and Alejandra Bravo (Boston: Centre for Agriculture and Biosciences International, 2015): 1–4.

14. In part for this reason, some have argued for policies that require companies to pull their transgenic crops off of the market once resistance emerges. However, this approach would work best if all countries, or at least all countries in a region, comply, especially in regions in which organisms can move easily across international borders.

15. As Fowler gathered copies of seeds from around the world, he knew he would need copies of Vavilov’s seeds. John Seabrook reports in his New Yorker article that when Fowler went to Vavilov’s collection, he did not know what he would find. Some said the collections still contained seeds; others said that many of the seeds had died and that much of what Vavilov gathered had gone literally to rot. To get to the seeds, Seabrook and Fowler, together, met with Nikolai Dzubenko, the man who now sits in Vavilov’s office and maintains his legacy. They ate with him in a room in the same building where Vavilov’s seed savers died during the siege. They ate “pastries, fruits, cold meats, cheeses, juice,” and drank vodka. On that day, Fowler, who was sick, toured the new storage facilities of the VIR, where things were shiny but not yet functional. So, by reports, they remain.

16. The headquarters of the Nordic Gene Bank is in Alnarp, Sweden.

17. Via a donation to the Global Crop Diversity Trust. This donation also supported work to produce extra copies of seeds in the seed banks of developing countries and then to ship the extras to Svalbard.

18. The perception both in the United States and Europe is that transgenic crops are less healthful than conventional crops. A study conducted by the Pew Research Center in 2015 found that 57 percent of Americans thought it was harmful to eat genetically modified food. Yet so far evidence of health problems associated with consuming transgenic crops is lacking. The National Academy of Sciences, the American Medical Association, the American Association for the Advancement of Science, and the World Health Organization have concluded that products made from transgenic crops now on the market are safe to eat. Of course the transgenic crop we are talking about is, mostly, corn—corn that is being used, in part, to produce high-fructose corn syrup. No one debates the fact that high fructose corn syrup is bad for you—it is—but its negative impact has little to do with whether the corn is transgenic. We should continue to be cautious about each new thing we consume, but nothing about the process of making a transgenic crop, as opposed to breeding a crop via more conventional means, poses a categorically new risk.

19. Transgenic crops with Bt genes might, for example, have negative effects on beneficial or rare insects. Monarch butterflies in particular have been the subject of concern. Early on, one study demonstrated Bt crops’ negative effect on monarch butterflies (via pollen). A series of subsequent studies has, however, found no effect on monarch butterflies, whether at concentrations of Bt toxins like those actually found in fields or at even higher concentrations. Other studies show that many beneficial insects (those that eat pests) do better on Bt crops than they do on Green Revolution varieties sprayed with pesticides, because the pesticides kill the beneficial insects as well as the Bt crops’ target pests. Crops that are engineered to be resistant to herbicides, on the other hand, seem to be a different story. These crops lead farmers to spray large quantities of herbicides that spill over into adjacent habitats and river systems, killing plants and polluting waterways and aquifers. Each transgenic crop is likely to be different in its consequences. See Emily Waltz, “GM Crops: Battlefield,” Nature 461 (September 3, 2009): 27–32; Mike Mendelsohn, et al., “Are Bt Crops Safe?”, Nature Biotechnology 21, no. 9 (September 2003): 1003–9, doi:10.1038/nbt0903-1003; Richard L. Hellmich, et al., “Monarch Larvae Sensitivity to Bacillus thuringiensis–Purified Proteins and Pollen,” Proceedings of the National Academy of Sciences of the United States of America 98, no. 21 (October 9, 2001): 11925–30.

20. The risk of unknown consequences is a reasonable one when confronted with new technologies. It was reasonable in the early days of heart transplants, when transplants were performed before they were safe or beneficial. It was reasonable in the early days of nuclear power. Urging caution upon the progress of technology has, historically, often been justified. There is a reason Mary Shelley’s Frankenstein still resonates. In the cases of transgenic crops, the worry relates to whether their genes might spread to other organisms. The worry relates to unknown things they might do to our bodies. The worry relates to the unknown. The worry should apply to any crop, just as it should apply to any pesticide, even those used on organic crops (which, ironically, is where Bt was first sprayed and is still used).

21. Jonathan Knight, “Crop Improvement: A Dying Breed,” Nature 421 (February 6, 2003): 568–70.

22. Kenneth J. Frey, National Plant Breeding Study—I: Human and Financial Resources Devoted to Plant Breeding Research and Development in the United States in 1994 (Ames, IA: Iowa State University, Iowa Agriculture and Home Economics Experiment Station, 1996).

23. Virginia Gewin, “New Film Traces Cary Fowler’s Quest to Build the Doomsday Seed Vault,” Science, May 15, 2015, at http://www.sciencemag.org/news/2015/05/new-film-traces-cary-fowler-s-quest-build-doomsday-seed-vault.

24. Knight, “Crop Improvement.”

25. David Greene, “Researchers Fight to Save Fruits of Their Labor,” Morning Edition, August 30, 2010, at http://www.npr.org/templates/story/story.php?storyId=129499099.

26. Ibid.

27. Ibid.

28. Tom Parfitt, “Pavlovsk’s Hopes Hang on a Tweet,” Science 329 (August 20, 2010): 899.

29. See the order at http://www.vir.nw.ru/news/14.05.2012_en.html.

30. See, for example, DivSeek: http://www.divseek.org/mission-and-goals/.

Chapter 15

1. Some can be found in Vavilov’s collection, potentially including those collected by Vavilov himself. Others are in the USDA’s National Small Grains Collection. Others still are in the ICARDA collection, in Syria, or the doomsday vault, in Norway.

2. Tom Clarke, “Seed Bank Raises Hope of Iraqi Crop Comeback,” Nature 424 (July 17, 2003): 242.

3. Glen R. Gibson, James B. Campbell, and Randolph H. Wynne, “Three Decades of War and Food Insecurity in Iraq,” Photogrammetric Engineering and Remote Sensing 78, no. 8 (August 2012): 885–95.

4. Issued by Paul Bremer, then head of the Coalition Provisional Authority.

5. Or, as some have suggested, maybe the change came about because of beer. Several authors have now suggested that even before agriculture beer was made from sprouted grain (particularly barley) left to rot. The slurry was consumed. It was enjoyed. Soon so much grain was being gathered to make beer that not enough was left over to eat. More was needed. Alcohol may have figured similarly in the earliest days of domestication of corn in the Americas and rice in Asia. For more on the settlements in which grains were first gathered see Riehl, Simone, Mohsen Zeidi, and Nicholas J. Conard. “Emergence of agriculture in the foothills of the Zagros Mountains of Iran.” Science 341.6141 (2013): 65–67. For more on the role of climate in the subsequent transition to active agriculture see Borrell, Ferran, Aripekka Junno, and Joan Antón Barceló. “Synchronous environmental and cultural change in the emergence of agricultural economies 10,000 years ago in the Levant.” PloS one 10.8 (2015): e0134810.

6. In many cases new traits were favored in seeds by farmers passively. That is, farmers did not necessarily choose these traits as much as the process of planting, gathering, and storing seeds favored some traits over others. Nonshattering, for example, has been argued to have emerged in some grains as a chance mutation, one that, as Greg Anderson noted in an e-mail to me, is bad for the plants. The plants with grass seeds (which are really a kind of tiny fruit, a caryopsis) that shattered were more likely to be dispersed in the field, either because the shattered seeds blew in the wind or rode on mammals. But those that did not shatter, the rare few with a mutation that prevented shattering, were more likely to be gathered, more likely to be stored, and more likely to be planted anew the next year. Farmers didn’t search out certain genes. Instead they collected the seeds that hadn’t fallen off the plant and thus favored the genes for seeds that didn’t shatter, that didn’t fall.

7. Where durum just means hard. The grains of durum wheat are relatively hard to grind.

8. Durum wheat appears to be a cross between a grass called einkorn and another grass—we don’t yet know which one. This cross doubled the number of copies of chromosomes durum wheat has relative to either ancestor. Durum wheat was then later crossed with another grass, goat grass, and produced a wheat variety with two more sets of chromosomes, a variety that gave rise to bread wheat. Most wheat grown today is bread wheat.

9. It was a realm complete with names, so recent is our civilized history. The first ruler of this empire was Sargon of Akkad. Independent cities (Uruk, Ur, Umma, Kish) preceded the empire over which Akkad ruled. He united the cities and created, in its grandest sense, Babylonia. It was an empire we would recognize in many respects.

10. Most accounts now suggest that early agriculture was so desperate that, with its dawn, life expectancies decreased. Even where the total number of calories available to a place increased because of agriculture, the nutritional value of those calories decreased, and the social inequalities of their distribution increased (at least initially). Pathogens became common. Bones found at archaeological sites from this time bear the pocks of malnutrition; teeth, for the first time, frequently bore signs of abscesses.

11. Ahmed Amri, et al., “Chromosomal Location of the Hessian Fly Resistance Gene H20 in ‘Jori’ Durum Wheat,” Journal of Heredity 81, no. 1 (1990): 71. Ahmed Amri, et al., “Complementary Action of Genes for Hessian Fly Resistance in the Wheat Cultivar ‘Seneca,’” Journal of Heredity 81, no. 3 (1990): 224–27; Ahmed Amri, et al., “Resistance to Hessian Fly from North African Durum Wheat Germplasm,” Crop Science 30, no. 2 (1990): 378–81.

12. ICARDA, as a reminder, is one of fifteen similar centers, each with a specific goal. Each center focuses on saving seeds as well as on working with farmers to save local farming practices. One center focuses on rice—the International Rice Research Institute, in the Philippines. Then there is the International Potato Center, in Peru, about which I have written (see page 198). Two of these centers, ICARDA and CIMMYT, both have a focus on wheat. But whereas CIMMYT focuses on Green Revolution wheats, which grow well with lots of water and fertilizer, the varieties ICARDA works on do the opposite: they do well with little water and little in the way of chemical inputs.

13. This variety alone had a huge effect in Syria, reducing by half the area that needed to be sprayed with pesticides against sunn pests.

14. Akia Kitoh, et al., “First Super-High-Resolution Model Projection That the Ancient ‘Fertile Crescent’ Will Disappear in This Century,” Hydrological Research Letters 2 (2008): 1–4, doi:10.3178/HRL.2.1.

15. We are eager to believe ourselves, as humans, too clever to succumb to simple tragedies such as those posed by climate. The archaeologist Joseph Tainter said, for instance (wrongly, as it turns out), that it is doubtful that “any large society has ever succumbed to a single-event catastrophe.” See Joseph A. Tainter, The Collapse of Complex Societies (Cambridge, UK: Cambridge University Press, 1990).

16. Alexia Smith, “Akkadian and Post-Akkadian Plant Use at Tell Leilan,” in Seven Generations Since the Fall of Akkad, ed. Harvey Weiss (Wiesbaden: Harrassowitz Verlag, 2012): 225–40.

17. Harvey Weiss, et al., “The Genesis and Collapse of Third Millennium North Mesopotamian Civilization,” Science 261, no. 5124 (August 20, 1993): 995–1004.

18. Pinhas Alpert and Jehuda Neumann, “An Ancient ‘Correlation’ Between Streamflow and Distant Rainfall in the Near East,” Journal of Near Eastern Studies 48, no. 4 (October 1989): 313–14.

19. Hugh Garnet McKenzie, “Skeletal Evidence for Health and Disease at Bronze Age Tell Leilan, Syria” (master’s thesis, University of Alberta, 1999).

20. For more on this amazing history, see Elizabeth Kolbert, “The Curse of Akkad,” in Field Notes from a Catastrophe: Man, Nature, and Climate Change (New York: Bloomsbury USA, 2006), and Harvey Weiss, “Late Third Millennium Abrupt Climate Change and Social Collapse in West Asia and Egypt,” in Third Millennium BC Climate Change and Old World Collapse, ed. H. Nüzhet Dalfes, George Kukla, and Harvey Weiss (Berlin, Heidelberg, and New York: Springer International Publishing, 1997), 711–23.

21. Editorial, “Seeds in Threatened Soil,” Nature 435 (June 2, 2005): 537–38, doi:10.1038/435537b.

22. Iraq faced the same drought, but it did so without the accompanying drawdown of groundwater. In addition, much of the food being consumed in Iraq came during those years—and still comes—from subsidized imports from the United States and Europe, imported grains cheaper to buy than to grow. My reconstruction of the drought and its consequences in Syria is based heavily on the excellent work of Colin Kelley and his colleagues. See Colin P. Kelley, et al., “Climate Change in the Fertile Crescent and Implications of the Recent Syrian Drought,” Proceedings of the National Academy of Sciences 112, no. 11 (March 17, 2015): 3241–46.

23. The trust was set up by CGIAR and the United Nations’ Food and Agriculture Organization (FAO).

24. United States Department of Agriculture, Foreign Agricultural Service, Commodity Intelligence Report, “Syria: Wheat Production in 2008/09 Declines Owing to Season-Long Drought,” at http://www.pecad.fas.usda.gov/highlights/2008/05/Syria_may2008.htm.

25. And, frankly, so was much of the Middle East. In the broader region described as CWANA—Central and West Asia and North Africa, a region that includes a billion people—only Kazakhstan, Turkey, and Syria produced enough wheat before 2011 to feed their people. Now, just Kazakhstan and Turkey do. Wheat is key to the story of food production and consumption in this region, both because it is the most consumed crop (by far, comprising 37 percent of calories) and because it is the only crop whose yield and production have been increasing in the region as populations have increased.

26. Anthony Sattin, “Syria Burning: ISIS and the Death of the Arab Spring Review—How a Small-Scale Revolt Descended into Hell,” The Guardian, August 9, 2015, at http://www.theguardian.com/books/2015/aug/09/syria-burning-isis-death-arab-spring-review-revolt-hell.

27. The research on characterization and multiplication of genetic resources and on variety development were relocated to the research platforms established in Lebanon, Ethiopia, India, and Morocco. There, workers took measurements of yields, yields that would be important when the war was over, so that the very best crops could be shared with farmers in Syria and beyond.

28. Hazem Badr, “Syria’s ICARDA Falls to Rebels, but Research Goes On,” SciDevNet, May 22, 2014, at http://www.scidev.net/global/r-d/news/syria-s-icarda-falls-to-rebels-but-research-goes-on.html.

29. Virginia Gewin, “Crop Seed Banks Are Preserving the Future of Agriculture. But Who’s Preserving Them?,” Policy Innovations, November 19, 2015, at http://www.policyinnovations.org/ideas/commentary/data/00400.

30. The statement is in a press release from ICARDA dated September 26, 2015: https://www.icarda.org/update/press-release-icarda-safeguards-world-heritage-genetic-resources-during-conflict-syria#sthash.LoKw8vkc.dpbs.

31. Jason Ur, “Urban Adaptations to Climate Change in Northern Mesopotamia,” in Climate and Ancient Societies, ed. Susanne Kerner, Rachael Dann, and Pernille Bangsgaard (Copenhagen: Museum Tusculanum Press, 2015): 69. In this paper Ur reconstructs shifts in the approach to agriculture in two fascinating ways. First he considers the extent of the intensification of agriculture based on the density of potsherds in fields and the number of fields containing potsherds. Potsherds are interpreted to be the residue of an approach to the fertilization (manuring) of fields that included waste of several kinds, of which the potsherds are all that remains. In addition, he reconstructs the extensification of agriculture (the proportion of the landscape farmed) by looking at what he calls hollow ways but that one might also describe as sunken trails. The trails were dug into the landscape by foot traffic. They exist where foot traffic was particularly intense. Ur interprets the intensification of foot traffic and presence of sunken trails as evidence that the landscape between the trails had become so filled with agriculture that any other route would be difficult. For an alternate (and perhaps less hopeful) interpretation of the same sites see Weiss, Harvey. “Quantifying collapse: The late third millennium Khabur Plains.” Seven generations since the fall of Akkad: Wiesbaden, Harrassowitz Verlag (2012): 1–24.

32. The only change, aside from a decline in health and well-being, that seems to have preceded the collapse of Leilan was not a change in agriculture. It was rather the investment in larger and more religious buildings. As things fell apart, they begged more of their gods. This proved to be an insufficient way of dealing with climate change.

33. In the spring of 1988 a rural farmer in Uganda saw something strange on his wheat. This wheat had spots, bumps, and eruptions along its stem. Each one, upon closer examination, appeared to be releasing a rusty powder. The powder, the farmer well knew, having watched wheat for decades, was the spores of a fungus called a rust. That it was on the stem meant it was a stem rust.

Among farmers, stem rusts are a known evil. But they are an evil that had already been vanquished. The wheat growing in the field where the rust was found was resistant to rust. It was grown especially for this trait. It was not the tastiest wheat. It was not the fastest-growing wheat. But it was the wheat that would grow anywhere in the world without problems, its short stems clean and unblemished. It was impossible that the wheat growing in the farmer’s field had rust.

But nature can make the impossible happen. The impossible is natural selection’s ancient expertise. Natural selection produced the miniature elephant and the giant komodo lizard. It produced a hummingbird with a beak longer than its body and an isopod that eats the tongues of fish, and then, having removed them, sits in their place. Natural selection produced the wasp that flies from house to house, laying its eggs in the bodies of roaches. It is an infinitely creative carpenter, an amoral surrealist out among the flowers and leaves. Certainly this artist could also produce a rust able to live on rust-free wheat—which is just what appeared to have happened.

Chapter 16

1. As I reread the story about the preservation of smallpox, it seemed more ominous and premonitory than I remembered. The virus that causes smallpox is, indeed, kept at only two sites, one in a lab at the Centers for Disease Control and Prevention, in the United States, and another at the State Research Center of Virology and Biotechnology, in Koltsovo, Russia. The part of the story I did not know is the tragic preamble to this situation.

The last death caused by smallpox actually occurred after the disease was eradicated. A medical photographer, Janet Parker, was developing pictures in her darkroom at the University of Birmingham Medical School, in England. The people in the research lab on the floor below her darkroom were conducting research on smallpox. The smallpox virus from the lab below got into the vents and traveled through them to her darkroom, where she became infected. In response, the head of the department of microbiology, Henry Bedson, committed suicide. Smallpox research stopped, but the samples in the United States and Russia were saved. It was only many years later that other samples of smallpox started to turn up—samples akin to those in the collection of plant pathogens I visited. A sample of a smallpox scab was found in a book on Civil War medicine in Santa Fe, New Mexico. Later, several vials of the smallpox virus were discovered in a lab at the National Institutes of Health. Do other vials lurk elsewhere? Almost certainly.

2. Nelson G. Hairston, Frederick E. Smith, and Lawrence Slobodkin, “Community Structure, Population Control, and Competition,” American Naturalist 94, no. 879 (November–December 1960): 421–25. See also Lawrence B. Slobodkin, Frederick E. Smith, and Nelson G. Hairston, “Regulation in Terrestrial Ecosystems, and the Implied Balance of Nature,” American Naturalist 101, no. 918 (March–April 1967): 109–24.

3. This was most likely a fungus that consumes dead plants rather than living ones, a wood-decay fungus, but nonetheless its growth was a reminder of the less conspicuous and yet still metabolizing life all around me in the room.

4. Elsa Youngsteadt, et al., “Do Cities Simulate Climate Change? A Comparison of Herbivore Response to Urban and Global Warming,” Global Change Biology 21, no. 1 (January 2015): 97–105.

5. Or, given that we are talking about collections of pathogens and insects, maybe he should ride in on a giant white horsefly.

6. United Nations Department of Economic and Social Affairs, Population Division, “World Population Prospects, the 2015 Revision,” at https://esa.un.org/unpd/wpp/.

7. Simon R. Leather, “Taxonomic Chauvinism Threatens the Future of Entomology,” Biologist 56, no. 1 (February 2009): 10.

8. Knowing when and where a problem exists can seem boring. It is tedious. Yet increasingly it has become clear that the better we are able to know the where and when of problems, the better we will be at mitigating them. In the context of antibiotic resistance, for instance, a key challenge is knowing where bacterial pathogens resistant to antibiotics are and when they will be present. In the context of pesticide resistance, knowing where those pests are is similarly important. In all these cases, the advantage of knowing where the problem is partially comprises the ability to respond to the problem, but over the long term the advantage is more layered. It also includes the ability to plan in light of where problems are most likely to occur and to implement policies that are responsive to those companies or countries most associated with the problems. See, for example, Peter S. Jørgensen, et al., “Use Antimicrobials Wisely,” Nature 537, no. 7619 (September 7, 2016), at http://www.nature.com/news/use-antimicrobials-wisely-1.20534.

9. In Mesopotamia, archaeologists have turned up a clay tablet from around 1800 bce, for instance, containing advice on how best to water crops and get rid of rats. See Majda Bne Saad, “An Analysis of the Needs and Problems of Iraqi Farm Women: Implications for Agricultural Extension Services” (doctoral thesis, University College, Dublin, 1990).

10. For a great short history, see Gwyn E. Jones and Chris Garforth, “The History, Development, and Future of Agricultural Extension,” in Improving Agricultural Extension: A Reference Manual, ed. Burton E. Swanson, Robert P. Bentz, and Andrew J. Sofranko (Rome, Italy: Food and Agriculture Organization of the United Nations, 1997).

11. Erich-Christian Oerke, “Crop Losses to Pests,” The Journal of Agricultural Science 144, no. 1 (February 2006): 31–43.

12. David Hughes, “PlantVillage: Using Smartphones and Smart Crowds for Food Security,” TEDx talk (May 2015), at https://www.youtube.com/watch?v=CFWU6NoFbeA.

13. One of those scientists is Lindsay McMenemy at the Scottish Crop Research Institute, whom Hughes describes as being like “the Robin Hood of plant diseases, who robs from the rich and gives to the poor.” Lindsay takes information from the publishing houses and libraries in wealthy countries and works with Hughes and Salathé to make it available to everyone.

14. Well, they give a little bit of a damn. They still spend some of their time doing lovely basic biological research on obscure ants and their fungi (Hughes) and forming beautiful evolutionary theory (Salathé). They just give much less of damn than do most.

15. Tom Ward, “Plant Village Is Reclaiming Control of Our Crops,” HuffPost Tech, August 18, 2013, at http://www.huffingtonpost.co.uk/tom-ward/plant-village-is-reclaiming-control-of-our-crops_b_ 3776047.html.

16. Nik Papageorgiou, “Smartphones to Battle Crop Disease,” École Polytechnique Fédérale de Lausanne News (November 24, 2015), at http://actu.epfl.ch/news/smartphones-to-battle-crop-disease/.

17. Sharada Prasanna Mohanty, et al., “Using Deep Learning for Image-Based Plant Disease Detection,” Frontiers in Plant Science (September 22, 2016), doi: 10.3389/fpls.2016.01419.

Epilogue

1. Julia was a postdoc with Julie Urban (then at the NC Museum of Natural Sciences) and me.

2. Statements such as “in my lab” are never really as simple as they seem. Margarita was a postdoc working with Steve Frank, David Tarpy, and me, but physically Margarita mostly worked in Dave’s lab.

3. Squash bees are, simply put, wonderful. They are not social. They live solitary lives. Mother bees dig tunnels into the ground where they put little clumps of pollen. They then lay an egg on each clump of pollen. The eggs will develop into a new generation of bees. The pollen has to be gathered though, from squash plants. During this gathering of pollen, squash bees pollinate the squash plants in the mornings and evenings when the squash flowers are open and the bees are active. Or female squash bees do anyway. Male squash bees spend their mornings (and, in some cases, evenings) lurking around squash flowers, sipping nectar, waiting for female squash bees to show up so they can mate. During the day, the male squash bees then sleep off their exertion inside the closed squash flowers. If one squeezes closed squash flowers one will often find, inside, a sleeping and slightly nectar-drunk chubby little male squash bee. Honeybees also pollinate squash flowers, but don’t do so as effectively as squash bees, in part because they don’t like squash flowers, in part because they are active at the wrong time of day. Margarita studied genetic differences among populations of squash bees and was able to show that the squash bees that one finds in North America moved there several thousand years ago when Native Americans took squash from Mexico and moved it north. The squash bee moved with its plant and, as a result, you can now find these bees in your backyard nearly anywhere in North America. López-Uribe, Margarita M., et al. “Crop domestication facilitated rapid geographical expansion of a specialist pollinator, the squash bee Peponapis pruinosa” Proc. R. Soc. B. Vol. 283. No. 1833. The Royal Society, 2016.

4. Nature is sometimes unpleasant. The beetle transmits the pathogen when it poops in the wounds it creates when it feeds. The beetle poop, and the Erwinia inside it, gets deep into the plant through the wound and infects its xylem. Rojas, Erika Saalau, et al. “Bacterial wilt of cucurbits: resurrecting a classic pathosystem.” Plant Disease 99.5 (2015): 564–574.

5. Bottle gourds were domesticated in Africa and spread around the world in no small part because people liked to use the gourds as water containers (the bottle gourd was, somehow, already in the Americas, for instance, when Columbus arrived).

6. Morimoto, Yasuyuki, Mary Gikungu, and Patrick Maundu. “Pollinators of the bottle gourd (Lagenaria siceraria) observed in Kenya.” International Journal of Tropical Insect Science 24.01 (2004): 79–86.