Let’s Not Lose Our Minds
I was asked to give the keynote talk at “Science, Journalism, and Democracy: Grappling With A New Reality” at Rockefeller University on September 6, 2017 (video). This is what I said.
We’re here at this meeting to talk about science, journalism, and democracy. So let me begin by telling you about a newspaper article on a scientific experiment, an experiment that would end up having a major influence on government policy on a vital issue.
The vital issue was food. The experiment was carried out on wheat. Some varieties of wheat are known as spring wheat. They’re planted in the spring and grow soon afterwards. Winter wheat, on the other hand, is planted in the fall but does not produce its flowers till the spring. Winter wheat has the advantage of a much bigger yield. But there’s a catch.
A field full of winter wheat can get wiped out by something called Black Frost. This is not a creature from Game of Thrones. Black Frost is what happens when there’s a sharp cold snap in winter without any snow on the ground. Winter wheat needs that layer of insulation to survive extremely low air temperatures. Spring wheat never faces that risk.
This newspaper article I want to tell you about described a new idea. What if you could plant winter wheat in the spring? On the face of it, this shouldn’t work. Winter wheat actually needs the cold as a signal to prepare to flower when the soil gets warm. Plant it in the spring, and it doesn’t get the signal.
But this newspaper article recounted the work of a maverick young scientist that suggested otherwise. (We journalists do have a weakness for maverick young scientists.) Just before spring planting, he germinated some winter wheat seeds and then packed them in some snow for a few days. After this artificial chill, he planted the winter wheat in the springtime soil. And they soon flowered.
The article celebrated the “extraordinary scientific and economic value” of the research. It promised nothing less than saving the country from a food shortage.
The article I’m talking about appeared on October 8, 1929. The newspaper that published it was Pravda, the propaganda outlet of the Communist Party of the Soviet Union. And the title was “On the Sowing of Winter Cultures in Spring (The Discovery of Agronomist T.D. Lysenko).”
Trofim Lysenko was a little-known researcher at the time. He did his experiment in the early years of Stalin’s dictatorship, when Stalin was facing dangerous food shortages across the Soviet Union. He had just responded by forcing peasants onto collectivized farms, a terrible decision that would lead over the next decade to the deaths of millions by starvation.
Stalin also demanded that Soviet scientists help fight the crisis by finding better crops, and find them fast. The Soviet Union at the time was home to a thriving community of geneticists who were doing pioneering work to understand the nature of genes in animals and plants. In response to the crisis, Soviet geneticists threw themselves into producing better crops through genetics. But their results were coming too slowly for Stalin.
And then came Lysenko. Lysenko had a great backstory that fit Stalinist ideology. He wasn’t one of those fussy cosmopolitan experts. He was from a peasant family. And despite having little advanced education, he was succeeding where mainstream scientists were failing. As soon as the agricultural ministry learned about Lysenko’s experiment on winter wheat, they began promoting him as a scientific hero.
In fact, when Lysenko first described his research at scientific conferences in early 1929, other Soviet scientists roundly dismissed it. For one thing, it was nothing new. Plant breeders had already been trying to use cold temperatures for centuries to improve plant growth. But they had little or no success.
So why should Lysenko suddenly be getting his amazing results? Lysenko’s critics said he was getting nothing of the sort. He was running experiments that were so small and sloppy that they couldn’t be trusted. Even in the early years of Stalin’s rule, Russian scientists were still having vigorous open exchanges. That’s one of the essential ingredients of science, because it allows scientists to hold each other to high standards.
You wouldn’t know that from the Pravda article, though. It presented Lysenko’s experiment as an open and shut case. Pravda, it’s worth mentioning, was staffed by editors with little scientific training and with a lot of incentive to believe the government’s claim that Lysenko was right. In their article on Lysenko, they didn’t mention the scientific community’s objections. More fawning press coverage soon followed. Sometimes geneticists managed to get their objections known, but the newspapers quoted government spokesmen dismissing them as bourgeois.
This complicit journalism, historians have argued, helped lift Lysenko to the highest echelons of Soviet science. As the flattering press coverage poured out, he got a huge laboratory to run more experiments. He went on to become a leader of the national efforts to grow more food.
This power went to Lysenko’s head. He started making sweeping pronouncements about the nature of heredity itself. He claimed that chilling winter wheat plants did more than just allow farmers to sow them in the spring. The plants could then pass down this improved trait to their offspring.
An acquired trait in a plant could override its genes, in other words. In fact, Lysenko now said, genes didn’t actually matter to life. The evidence in favor of genes, evidence that had poured in for thirty years, meant nothing to him. He brushed off the science of genetics as a “bourgeois perversion.” His attacks got personal, as he vilified geneticists as “fly-lovers and people-haters.”
Soviet newspapers stuck to the same talking points. They broadcast Lysenko’s amazing claims, and they attacked genetics as a myth of the capitalist west. By ignoring genetics, they claimed, Lysenko would put the Soviet Union at the top of the scientific world.
Geneticists found the Soviet Union a hard place to work. Some lost their jobs. Geneticists from other parts of the world soon realized the Soviet Union was no longer a place to travel to in order to do innovative research. Hermann Muller, an American geneticist who later won the Nobel Prize, traveled to Leningrad’s Institute of Genetics in 1933. He hoped to work with the scientists there. He immediately discovered that Lysenko was running roughshod over Soviet science.
Muller spoke out against Lysenko in public. He even agreed to debate Lysenko in front of three thousand farmers and scientists. Muller tried to convince them that genes were real, that they stayed stable over generations. But the crowd shouted him down. They were swept away in the theater of Lysenko’s performance. After the debate, Muller realized he was now in grave danger and fled the Soviet Union.
He was not overreacting. Geneticists started ending up in jail. The greatest plant scientist of the early twentieth century, Nicholai Vavilov, had supported Lysenko early in his career. But now he spoke out against Lysenko’s attacks on the reality of biology. Vavilov was thrown in prison, where he starved to death in 1943.
The historian Mark Tauger has observed that some Soviet geneticists still managed to carry on their science. But they only managed to do so by disguising it — “by writing research plans in ways that deceived bureaucratic censors,” Trauger writes. They managed to publish some of their work in journals that used articles “on Lysenkoist themes as camouflage.”
Lysenko didn’t need the support of Soviet scientists for his power. Stalin was his patron. When Lysenko spoke at an agricultural conference held at the Kremlin in 1935, Stalin himself was in the audience. When Lysenko accused geneticists of being “saboteurs,” Stalin rose to his feet and yelled, “Bravo, Comrade Lysenko, bravo!”
Soviet newspapers provided Lysenko support as well. They repeatedly praised him with descriptions like “the distinguished son of the collective farm peasantry.” And they hounded Lysenko’s scientific victims. Newspapers ran hit pieces on individual geneticists, branding them as fascists. When a pair of Soviet scientists dared to publish a textbook that included Mendel, one newspaper condemned it with the headline, “Drive formal genetics from higher education!”
Lysenko kept promising that his new theory of heredity would dramatically increase Soviet crop production. But his increase never came. Stalin never asked other scientists whether Lysenko might be wrong. Instead, he continued to support Lysenko for years, damaging the Soviet agricultural economy in the process. This fiasco unfolded even as scientists in other countries were relying on genetics to develop new varieties of crops that would dramatically improve yields.
Meanwhile, Lysenko ratcheted up his attacks even more. In 1948, three thousand geneticists were fired at one shot. Their laboratory stocks of fruit flies — the best tools at the time to understand animal genes — were destroyed. One of scientist shot himself in the head. When another scientist wrote a 200-page review of all the harm Lysenko was doing to biology, he was sent to a gulag for seven years.
How did Soviet newspapers respond to these events? They ran cartoons showing geneticists wearing the white hoods of the KKK.
Valery Soyfer, a Russian biologist and historian, has written about how much Soviet science in general suffered in these years. The ranks of its leadership filled by people with good political instincts and little scientific training. Generations of students went through universities without getting a good education in the latest advances in science.
When Stalin died in 1953, Lysenko had amassed enough power to let him hold onto his post into the 1960s. Finally, Soviet scientists started mounting a campaign against him, which opened an investigation. Lysenko was pushed into retirement in 1965.
That investigation — along with later research — shows that Lysenko’s work was meaningless. Plants have genes that control how they use signals to decide when to flower. All the evidence indicates that Lysenko accidentally picked out rare variants of winter wheat with mutations that altered their schedule. It was nothing but good old genetics. That’s not to say that stress or heat or other experience couldn’t possibly affect heredity in plants. Some research indicates that what is known as epigenetic inheritance may have an important role in plants. But Lysenko put a stain on the entire line of inquiry, leading to years of neglect.
It’s been nearly ninety years since that Pravda article about Lysenko was published, helping to launch him on his dismal career. It’s been over fifty years since he fell at last. When you hear this story, you may think, “Well, that’s appalling, but it happened a long time ago, and in a faraway place. It has no meaning to us today in the United States in 2017.”
I disagree. The things we are discussing today at this meeting — democracy, science, and journalism — are three valuable institutions that have made life in this country far better than it would be without them. They are worth defending, and worth keeping free of corruption.
We can look back over history to see how, in different places and different times, each of these pillars cracked and sometimes even fell. We should not be smug when we look back at these episodes. We should not be so arrogant as to believe we are so much smarter or nobler that we’re immune from these disasters.
Instead, we should look at how those problems arose, and learn how we can keep them from happening. They do not happen overnight. It takes years, and it takes a gradual shift in many people’s norms and behaviors. When we look at science as it is today, we ought to ask, in what direction is it moving? The last thing we should want is for it to move even an inch in the direction of such terrible episodes.
The historian Timothy Snyder sums up the value of history with a short line in his new bestseller, On Tyranny: “History can familiarize, and it can warn.”
It’s good to look at stories like Lysenko’s and ask ourselves, what exactly appalls us about it?
— A government decided that an important area of research, one that the worldwide scientific community had been working on for decades, was wrong. Instead, they embraced weak evidence to the contrary.
— It ignored its own best scientists and its scientific academies.
— It glamorized someone who opposed that mainstream research based on weak research, turning his meager track record into a virtue.
— It forced scientists to either be political allies or opponents.
— It personally condemned scientists who supported the worldwide consensus and spoke out against the government’s agenda, casting them as bad people hell-bent on harming the nation.
— The damage to the scientific community rippled far, and lasted for years. It showed hostility to scientists from other countries, isolating them from international partnerships. It also created an atmosphere of fear that led to self-censorship.
— And by turning away from the best science, a government did harm to its country.
Let us turn to the here and now. In the 1930s, climate change was barely appreciated, but today it’s one of the most important scientific issues we face. For years now, the National Academy of Sciences and other groups of leading scientists have provided the U.S. government with their best analysis of what is happening as humans put billions of tons of heat-trapping gases into the air. They’ve synthesized decades of research to this end.
Thanks largely to human activity, the Earth’s surface has already warmed nearly 2 degrees since 1880, loaded the oceans with vast amounts of extra heat, lowered its pH, and raised sea levels. Glaciers are in retreat, and climate change is starting to influence extreme weather. If humans raising carbon dioxide concentrations at our torrential pace, climate scientists warn we will face much higher sea levels, and more extreme weather such as deadly heat waves. Oh, and by the way, climate change is projected to take a bite out of U.S. food production due to droughts and other impacts.
There is still a lot of debate about the precise response Earth will make to climate change. There was a lot of debate about genes in the 1930s. But we knew then that genes were real, and we know now that climate change is real. Even if some people say it isn’t, our best science says it is.
And how have our current leaders responded?
Our president tweeted the climate change is a hoax concocted by China.
He has just nominated Congressman Jim Bridenstine to head NASA, an agency which has taken on an irreplaceable role in monitoring the climate and the atmosphere from space. The web site On the Issues asked Bridenstine what his position was on climate change. He said, “There is no credible scientific evidence that greenhouse gas atmospheric concentrations, including carbon dioxide, affect global climate.”
Scott Pruitt, the man who runs the EPA, was recently asked if fossil fuels are the cause of climate change. He responded, “I would not agree that it’s a primary contributor to the global warming that we see.”
At the Department of Energy — energy being the crucial source of human-produced carbon dioxide, and new sources of energy being essential to slowing down climate change — Secretary Rick Perry recently also said carbon dioxide is not the primary cause of climate change. He blamed it, mysteriously, on “the ocean waters and this environment that we live in.”
These statements have no support from the scientific community, as you can see if you look at statements about climate change from scientific societies who study the subject, such as the American Geophysical Union and the American Meteorological Society. Neither Perry, Pruitt, or Bridenstine are scientists, I should add.
When Hurricane Harvey struck, climate scientists spoke publicly about their research that indicates climate change will provide more moisture and energy for storms. For this utterance, the EPA attacked them.
“The EPA is focused on the safety of those affected by Hurricane Harvey and providing emergency response support — not engaging in attempts to politicize an ongoing tragedy,” a spokesperson told the press.
Think about that: a branch of the Federal government personally vilified them as cynical sensationalists — for discussing a well-studied phenomenon that may affect countless lives in decades to come.
Scientists from 13 U.S. government agencies have put together a National Climate Assessment, which surveys the evidence for climate change. It paints a dire picture of the future. The report has not yet been officially released by the government. When these assessments are released every four years, it’s the president’s science advisor who typically signs off on them. But the new administration currently has no science advisor.
On top of that, the head of the EPA is now saying the National Climate Assessment needs to be peer-reviewed. A fact-checker would reply that the report has already been thoroughly peer reviewed by a panel of scientists. We’re left to wonder what sort of peers he has in mind.
Some in Congress are following suit. On August 29, Axios ran a story about Congressman Andy Biggs of Arizona, who calls climate change “a discredited theory.” They reported that Biggs has introduced an amendment that would wipe out the funding for the National Climate Assessment. Who needs to delay bad news if the bad news doesn’t get written up in the first place?
The White House administration eliminates all climate-related research at the Department of Energy in its proposed budget. At the EPA, the Washington Post reported yesterday that final approval for research grants has been taken away from environmental experts and put in the hands of a political appointee with no environmental protection experience. According to the Post’s sources, the appointee will kill any application with the “the double C-word” — climate change.
One member of the transition team at the EPA got to the heart of the matter, flatly declaring: “There is no such thing as climate science.”
And how is the scientific community responding? Many participated in the March on Science. Many others have spoken out about their research. But there are other responses that have a different echo. On August 25, Nature reported things in the Department of Energy are a lot like they are in the EPA: scientists supported by the department have been asked to remove references to climate change and global warming from the descriptions of their projects.
One scientist who does this research was chillingly realistic about this situation. “If that’s what it takes to keep science going for a couple of years, we will I guess play along.” Just a couple years, and somehow, magically, this will all be over.
Will climate scientists from other countries want to come to the United States to do research in this environment? Will they end up in staged debates in front of hostile crowds like Muller did? President Macron has invited American climate scientists to come to France. Was he just trolling us, or will we suffer a science drain from the country that has till now led the world in climate science?
Most of what I just described has happened in just the last few weeks — in some cases the last few days. For science journalists starting off in their careers, I imagine the experience has been pretty overwhelming, perhaps even incomprehensible. What on Earth are they supposed to do?
As a not-so-young science writer, I would like to offer seven bits of advice — not just reporting specifically about climate in 2017, but about any other subject in science in today’s cultural climate.
I became a science journalist in 1990. I was an assistant editor at Discover. Andy Revkin, who now writes for ProPublica, was a senior editor at the time. Right before I started, he had just written a cover story on global warming. It was, I believe, the first cover story about global warming ever. Revkin wrote about NASA’s climate scientist Jim Hansen and his testimony about climate models showing an increase in temperature due to human carbon emissions.
The story did not make huge waves. People took note of it, but it felt too abstract, too far off in the future. It did not prompt a flood of attacks on Discover. That’s because we were working at the dawn of modern climate journalism.
I wrote a lot about evolution at the time, and I was attacked by creationists for it. Ever since the Scopes monkey trial, evolution has been a political football. I got a first-row seat where I could watch the art of attacking science. Creationists used false ideas about balance to demand equal time for creationism. They gave creationism other names. They cherry-picked my articles to convey the opposite of what I wrote. They personally attacked biologists as out-of-touch elites who hated good people.
I also started to write some pieces about climate change, because if you want to understand the history of life and its future, you have to learn about the climate in which it evolves. And I was startled to discover a new group of people who used the same tactics to cast doubt on climate science.
In 1994, for example, I wrote about paleoclimatology. For the most part, scientists were finding that, in the past, the level of carbon dioxide influenced the climate in a straightforward way. But there were odd periods. Some 440 million years ago, for example, carbon dioxide levels were 16 times higher than in the 1990s. But way back then, there was ice at the South Pole.
Over a decade later, a climate denialist reached back to that article to quote-mine it for a column at the site Town Hall. “As Carl Zimmer has noted in Discover, at times in the earth’s past, we’ve had considerably more carbon dioxide in the air that we do today, and yet it’s debatable whether the temperature was significantly warmer…. Doesn’t this suggest that there isn’t anywhere near as much of a close relationship between greenhouse gasses like carbon dioxide and the temperature as many people seem to believe?”
He quoted me, but he left out the part where I described some compelling solutions to these puzzles. The sun has been getting brighter over its long lifetime, for example. That means that it was four percent dimmer 440 million years ago. So the carbon dioxide had less radiation to trap. Such a compelling explanation would not fit his narrative.
I then watched people use this sort of move over and over again to raise doubt about climate science — in columns, on the radio, on television, on the floor of Congress. Climate deniers used other familiar techniques. They kept calling for false balance. They vilified scientists, casting them as enemies who could never be trusted. Climate scientists were portrayed in a global conspiracy to control people’s lives and to somehow enrich themselves with grants from the National Science Foundation.
So my first suggestion to flummoxed science journalists is: read history.
Not just about Lysenko, but about recent history of science and politics and the media. For climate change in particular, read books like The Discovery of Global Warming by the historian Spencer Weart, or Merchants of Doubt by the historian Naomi Oreskes and Erik Conway. What seems new actually has deep roots.
Number two: don’t give up on old-fashioned principles. Resist the simplistic notion that drastic times call for drastic measures. Remember that science journalism is a lot like science: we should try to get as close as we can to the truth about science — about its findings and its practice and its impact. Do not let your astonishing Twitter feed make you forget your job.
Number three: don’t get bullied away from your principles. Don’t let someone on Twitter or a TV show guilt you into doing bad reporting in the name of false balance. And don’t let people push you to hide legitimate disagreements either.
If you’re writing about plate tectonics, and there are geologists who have published peer-reviewed work that puts them in conflict — let’s say, they’re in a debate about how the Andes Mountains formed — report that debate. But don’t feel guilty because someone wants equal time for their 200-page pdf online about how there is not continental drift because the Earth is hollow. Does this make your reporting biased? That’s an absurd question for a science journalist. Hello, my name is Carl Zimmer, and I am pro-plate tectonics.
Number four: Always write for the public. In the United States, we thankfully have a first amendment here and aren’t dominated by state-run media. But even in a free society, we must vow not to do stenography for people in power, no matter who they are, no matter what the topic.
It may be easy to keep this in mind in some cases, and harder in others. For over thirty years, governments have urged people to keep their intake of fat low. Many reporters have passed on that advice uncritically, without looking at the statistics of the underlying research. The scientific evidence behind that policy was not strong when the policy went into practice, and a growing number of studies have challenged the low-fat mantra. The latest one came out at the end of August, looking at 130,000 people. It found people with a high-carbohydrate diet were more likely to die. A diet rich in fats did not have that effect. Don’t ignore this sort of solid, large-scale research because it might not agree with a public health message.
Number five: Remember that circulation managers are heroes of journalism, no less than a reporter who climbs to the top of a glacier in Greenland. They bring in the audience, in print and online. They help make journalism organizations solvent for the long term.
You can help by becoming a circulation manager yourself, or by thinking like one. People who care about science should not end up huddled around their own campfire, taking turns as speaker and audience. Building bigger audiences means trying out new kinds of media. What does each new format let you do that you couldn’t do before? What audience can you reach?
Also ask yourself, why aren’t you reaching more people? Are you failing to reach a big demographic swath? Climate change and other big stories of science affect everyone. Informed democracies need to know about them.
But that means acknowledging that people may not draw the conclusions from your work that you may think are obvious. And it’s not because they don’t understand, or because they don’t have enough information. Get to know the research on the psychology of science communication — how everyone filters information about science through our identity and cultural affiliations.
Number six: remember that science is at the heart of humanity’s search for truth. In the world of journalism, science writers can feel on the outside looking in. No editor-in-chief of a major newspaper that I can think of got there after being a science writer. No anchor on CNN or network news did either.
But at a time when disinformation is rampant, people look to science as something to be protected. Michael Lewis, one of our most popular and talented journalists, made that choice in his recent piece in Vanity Fair: “Why The Scariest Nuclear Threat May Be Coming From Inside The White House.”
He reported how the new administration showed little interest in learning about key concerns of Department of Energy scientists — little things like making sure nuclear weapons don’t blow up by accident. Instead, Lewis reported, the new administration showed much more interest in finding out who in the department went to climate change meetings and wiping out all of DOE’s climate-research funding.
“You can’t gut the science,” John MacWilliams, associate deputy secretary of the Department of Energy, told Lewis. “If you do, you are hurting the country. If you gut the core competency of the D.O.E., you gut the country.”
You are better at reporting this stuff than anyone else. Let’s seize this moment.
Finally, number seven: Recognize that every science story can have a moral dimension, no matter how small it may seem. It’s easy to think a lot of what we do is just telling entertaining stories. We get to write about pandas and electrons.
But there is a moral code hidden in every story. Most research costs taxpayers money — why was this particular study of value? Each study has to adhere to good scientific practice to have a chance of showing us something new about how the world works. Did it?
And when a country slides into authoritarianism, it’s a mistake to believe that nice little science stories can offer refuge for a journalist. To illustrate what I mean by this, I want to end my talk with another story from Russia. This one comes from the Putin era, told by the journalist Masha Gessen.
Gessen has been getting a lot of well-deserved attention in the past year for her essays about autocracy, the experiences Russian journalists have under Putin, and the lessons that journalists and citizens in the United States can learn from them.
But Gessen is one of us. Her portfolio includes science journalism. She was even the editor of a Russian science magazine. So as we look at other times and places to plan our actions, we can look to her experience, which she wrote about in passing in a longer piece she published last year:
“In 2012, I was working as the editor-in-chief of a popular science magazine called Vokrug Sveta when Vladimir Putin, who fancies himself an explorer and a nature conservationist, took a liking to the publication. His administration launched a kind of friendly takeover of the magazine, one that the publisher could not refuse. I found myself in meetings with the Russian Geographic Society, of which Putin was the hands-on chairman. They wanted me to publish stories about their activities, most of which, as far as I could tell, were bogus. In exchange, they promised to help the magazine: at one point every school in Russia was ordered to buy a subscription (like many Kremlin orders, this one ended in naught). I felt a slow rot setting in at a magazine I loved, but I kept telling myself that I could still do a good job — and keep many fine journalists gainfully employed. Then I was asked to send a reporter to accompany Putin on his hang-gliding adventure with a migrating flock of endangered Siberian cranes. I refused — not on principle but because I was afraid that the reporter would see and describe something that would get the magazine in trouble. The publisher fired me, but then Putin called me in for a meeting and offered me my job back — legally, it wasn’t his to offer, but for practical purposes it was.
“In comparison to the Putin regime’s major abuses of power and suppression of the opposition, the story of the cranes and my firing does not deserve a mention. All that happened as a result of the hang-gliding trip (from what I know) was that two or three of the cranes were badly injured for the sake of the president’s publicity stunt, and I lost my job. But I also lost a bit of my soul and the sense of moral agency I had earned over decades of acting like my best journalist self. When Putin offered me my job back after the trip, I hesitated to say no: I loved that job, and I thought I could still edit a good magazine and keep some fine journalists employed. I didn’t want to imagine what would happen the next time I was asked to cover a Putin photo op or a fake story produced by his Geographic Society, which siphoned money off like every other part his mafia state. Fortunately for me, my closest friend said, ‘Have you lost your mind?,’ by which she meant my sense of right and wrong.”
Let’s not lose our minds.
Cohen, Barry M. “The descent of Lysenko.” Journal of Heredity 56.5 (1965): 229–233.
Cohen, Barry M. “The demise of Lysenko.” Journal of Heredity 68.1 (1977): 57–57.
Graham, Loren. Lysenko’s Ghost. Harvard University Press, 2016.
Ings, Simon. Stalin and the Scientists: A History of Triumph and Tragedy, 1905–1953. Grove/Atlantic, Inc., 2017.
Joravsky, David. The Lysenko Affair. University of Chicago Press, 2010.
Roll-Hansen, Nils. The Lysenko Effect: the Politics of Science. Humanity Press, 2005.
Soyfer, V. N. “The consequences of political dictatorship for Russian science.” Nature Reviews Genetics 2.9 (2001): 723.
Westerman, Frank. Brother Mendel’s Perfect Horse: Man and beast in an age of human warfare. Random House, 2013.
(Update 9/8: Clarified that winter wheat flower in the spring, rather than just growing. Thanks to Terry Daynard.)