The Book of Eels, Patrik Svensson [bill gates best books .TXT] 📗

must be made on it now, in this session of Congress.” Her eagerness and haste were not only rhetorical. She was dying herself. By the time Silent Spring was published, she had been diagnosed with breast cancer, and when she testified before the Senate subcommittee, the cancer had spread to her liver. She knew it was her last chance to turn her conviction into action—and she was successful, at least as far as the devastating pesticides were concerned. The use of DDT in agriculture was banned in the United States in 1972, largely thanks to Silent Spring’s enormous impact. But by then, Rachel Carson was dead. She passed away in April 1964, at the age of fifty-six. Her legacy will always be the attention she drew early on to the threat that has now become a widespread concern.

SEVERAL TIMES DURING THE MORE THAN THREE BILLION YEARS THAT life has existed on this planet, changes have taken place that have been so far reaching and drastic one could say they were tantamount to a kind of metamorphosis, each altering the very composition of life on earth. Five times, these changes have been so all encompassing, they’ve been given their own category. These five periods are usually called the five mass-extinction events.

The first of the mass-extinction events started about 450 million years ago, during the tail end of the Ordovician period, when life was still more or less confined to the oceans. Due to a cooling climate, which was in turn a consequence of continental drift, approximately 60 to 70 percent of all species became extinct over a period of about ten million years.

The second mass-extinction event was also caused by devastating global cooling, about 364 million years ago; by its end, 70 percent of all living species had been wiped out.

The third mass-extinction event was the deadliest. It occurred in the transition between the Permian and Triassic periods, approximately 250 million years ago, and killed off more than 95 percent of all species. There is no consensus on the cause, but the most likely answer is that a confluence of events led to dramatic climate change.

The fourth mass-extinction event took place over a relatively long time between the Triassic and Jurassic periods, about 200 million years ago, and saw the demise of up to 75 percent of all species.

The fifth mass-extinction event is the most famous. Sixty-five million years ago, a meteor is thought to have struck the Yucatán Peninsula; the impact was at least one contributing factor to the extinction of the dinosaurs, along with 75 percent of the rest of the world’s species.

The flora and fauna of our planet have undergone more metamorphoses than that, some almost as comprehensive, but relative to the long history of life, mass extinctions are nevertheless a very rare phenomenon. Species die, animals and plants come and go, but the time frame of this process is usually so long it doesn’t fundamentally disturb the order of things. That is the normal way of life: occasional goodbyes, not holocausts.

And yet many researchers are positing that what we are experiencing now is not the normal way of things, that we are, in fact, living the sixth mass-extinction event. In August 2008, the American biologists David Wake and Vance Vredenburg wrote an article entitled “Are We in the Midst of the Sixth Mass Extinction?” It was published in the scientific journal Proceedings of the National Academy of Sciences, and even though the authors were not the first to ask this question, their answers were so persuasive that the threat no longer seemed hypothetical but rather highly probable.

Wake and Vredenburg focused specifically on amphibians and salamanders and were able to show that yes, some form of mass extinction was unquestionably already underway. Of the earth’s circa 6,300 known amphibian species, at least a third were already endangered, and this development showed every sign of getting rapidly worse.

One of the people who read the article was the science journalist Elizabeth Kolbert. Her book The Sixth Extinction was published in 2014 and summarized what we know about the potential extinction event happening right now. About a third of all corals are at threat of extinction; so are a third of all sharks, a quarter of all mammals, a fifth of all reptiles, and a sixth of all birds. This extinction event may not turn out to be as far reaching as any of the big five, but the threat is nevertheless so great, and accelerating so rapidly, that it’s not out of the realm of possibility. If things carry on like this, there’s much to suggest that the number of species on our planet will be halved in just one hundred years.

That is exceptionally fast—previous mass extinctions took place over millions of years; now we are talking about centuries—but what makes the current extinction event truly unique is that for the first time in history, there’s a living perpetrator. The culprit is not a celestial body, or continental drift or volcanic eruptions; it’s a creature. One of the many species inhabiting this planet has conquered it, and in so doing has caused the massive destruction of the habitats of all other species. It has managed to change not just the surface of the earth but its atmosphere, too. No other species has ever come close to exercising that kind of impact on life. On different forms of life. On all life.

“If Wake and Vredenburg were correct,” Elizabeth Kolbert writes, “then those of us alive today not only are witnessing one of the rarest events in life’s history, we are also causing it.”

BUT WHY IS THE EEL IN PARTICULAR DYING? WHAT ARE THE SPECIFIC circumstances that have made this seemingly timeless survivor unable to carry on? To start, the question is accompanied by a theoretical problem. As we know, asking why can never be the first step in tackling a scientific problem. One has to start at the beginning. First, we establish that something’s happening: Is the eel dying? Then we