Darwin writes: what animals could you imagine to be more distant from one another than a cat and a bumblebee? Yet the ties that bind these two animals, though at first glance nonexistent, are on the contrary so strict that were they to be modified, the consequences would be so numerous and profound as to be unimaginable. Mice, argues Darwin, are among the principal enemies of bumblebees. They eat their larvae and destroy their nests. On the other hand, as everyone knows, mice are the favorite prey of cats. One consequence of this is that, in proximity to those villages with the most cats, one finds fewer mice and more bumblebees. So far so clear? Good, let’s go on.
Bumblebees are the primary pollinators of many vegetable species, and it is common knowledge that the greater the amount and the quality of pollination the greater the number of seeds produced by the plants. The number and the quality of seeds determines the greater or lesser presence of insects, which, as is well known, are the principal nutriment of numerous bird populations. We could go on like this, adding one group of living species to another, for hours on end: bacteria, fungi, cereals, reptiles, orchids, would succeed one another without pause, one by one, until we ran out of breath, like in those nursery rhymes that connect one event to another without interruption. The ecological relationships that Darwin brings to our attention tell us of a world of bonds much more complex and ungraspable than had ever previously been supposed. Relationships so complex as to connect everything to everything in a single network of the living.
There is a famous story along these lines told for the first time by the German biologists Ernst Haeckel and Carl Vogt. As the story goes, the fortunes of England would seem to depend on cats. By nourishing themselves on mice, cats increase the chances of survival of bumblebees, which, in turn, pollinate shamrocks, which then nourish the beef cows that provide the meat to nourish British sailors, thus permitting the British navy—which, as we all know, is the mainstay of the empire—to develop all of its power. T. H. Huxley, expanding on the joke, added that the true force of the empire was not cats but the perseverant love of English spinsters for cats, which kept the cat population so high. In any event, underlying the joke is the simple truth that all living species are connected to one another in some way or other by relationships, visible or hidden, and that acting directly on one species, or simply altering its environment, can have totally unexpected consequences. Darwin tells us that trying to imagine the final consequences of any alteration in these relationships would be as “hopeless” as throwing up a handful of sawdust on a windy day and trying to predict where each particle would land. History is full of such attempts, almost always gone wrong, to modify the presence or the activities of single species.
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In 1958, Mao was rightly convinced that some of the scourges that had plagued the Chinese for centuries had to be eradicated immediately and in a radical fashion. Keep in mind that when the Communists took power in the autumn of 1949, they found themselves governing a nation gravely distressed by a soaring incidence of infectious diseases: plague, cholera, measles, tuberculosis, polio, and malaria were endemic in most of the country. Cholera epidemics were very frequent, and the infant mortality rate ran as high as 30 percent.10
The creation of a national health service and a massive vaccination campaign against plague and measles were the first, meritorious, actions undertaken to improve the situation. Water purification and sewage treatment infrastructure was installed throughout the country, and imitating what had been done previously in the Soviet Union, health care personnel were trained and sent into rural areas to serve as proper health care administrators, educating the population in basic health and hygiene practices and treating diseases with all available resources. But, obviously this wasn’t enough; the diffusion of carriers that spread disease had to be curtailed: mosquitoes, responsible for malaria; rats, spreaders of plague; and, finally, flies had to be exterminated. These three scourges from which China had to be liberated were soon joined by a fourth: sparrows, which by eating fruit and rice cultivated laboriously in the fields were one of the most terrible enemies of the people. Chinese scientists had calculated that each sparrow ate ten pounds of grain per year. So for every million sparrows killed, food for 60,000 people would be saved.
This information was the basis for the “Four Pests Campaign,” and sparrows were public enemy number one. Today, any proposal for ecosystem modification as radical as this call to eliminate four species from a territory as vast as China would, obviously, be considered ill-considered. But in 1958, lots of people thought it seemed like a good idea. So the party’s campaign to recruit the citizenry to combat these four pests was begun. Millions of posters were printed up illustrating the necessary eradication and the means to implement it.
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Although Klochko’s account makes it seem that all this activity was not very effective, the actual results were, unfortunately, devastatingly successful. The government acclaimed the schools, working groups, and governmental agencies that achieved the best results in terms of number of pests killed. The estimates provided by the Chinese government, totally unreliable for their enormity, indicated a billion and a half rats and a billion sparrows killed. Even though they are enormously exaggerated, these figures nevertheless tell us of a massacre whose dramatic consequences would soon be evident. Sparrows, in fact, do not feed exclusively on hulled grains. On the contrary, their main food supply are insects.
In 1959, Mao, realizing his mistake, replaced the sparrows as a target pest with beetles, but the damage had already been done. The almost total lack in China not only of sparrows (which had to be reintroduced from the USSR) but of practically all other birds led to an immeasurable increase in the insect population. The number of locusts began to increase exponentially, and immense swarms of insects making their way through the fields of China destroyed most of the crops. From 1959 to 1961, a series of ill-starred events partially related to natural disasters and partly caused by the mistaken reforms of the Great Leap Forward (the idea to exterminate the sparrows being one of the worst), led to three years of famine so harsh that it caused the deaths of an estimated 20 to 40 million people.
Playing with something whose working mechanisms are not well known is clearly dangerous. The consequences can be completely unpredictable. The strength of ecological communities is one of the engines of life on Earth. At every level, from the microscopic to the macroscopic, it is these communities, understood as relationships among the living, that allow life to persist.
- Excerpts from the book, The Nation of Plants by Stefano Mancuso.