The Sixth Extinction: Chapter 1 Summary & Analysis

The Panamanian town of El Valle de Antón, is located within a massive volcanic crater. Until very recently, golden frogs were an extremely common sight in El Valle. This species was known to be extremely toxic. Thus, when the golden frogs of El Valle began to disappear, few people saw it as a crisis.

Kolbert herself found out about the golden frogs of El Valle in a children’s nature magazine. The magazine said that biologists in the town were trying to build a special facility to save the golden frogs; in the meantime, they captured a few dozen frogs and kept them in a “frog hotel,” where they pampered the frogs and fed them well. Around the same time, Kolbert came upon a scientific article arguing that the world was in the midst of a sixth mass extinction, which would be devastating for amphibians and many other life forms. According to the article, there had been five previous mass extinctions, the most recent of which took place during the Cretaceous period, when, famously, the dinosaurs died out. Kolbert was so struck by the article on mass extinction that she bought a ticket to Panama to learn more—surely a mass extinction, one of the rarest events in the history of life on Earth, was worth researching.

In El Valle, Kolbert visits the El Valle Amphibian Conservation Center, or EVACC, which is largely devoted to saving the golden frog, or Atelopus zeteki, from going extinct. Edgardo Griffith, the director of the EVACC, is a young man who has spent most of his adult life studying different amphibians. Griffith claims that the world is losing frog species before people even know they exist. Though this is a tricky claim to prove, the fringe-limbed tree frog (which was discovered in 2005 and went extinct in the wild a few years later) suggests that it’s possible, if not likely.

The extinction of frog species is particularly noteworthy because, historically, frogs are some of nature’s most resilient animals, capable of surviving in many different environments. The earliest amphibians appeared millennia ago, when the Earth’s land was part of one landmass, now known as Pangaea. Today, there are at least 7,000 different frog species, which inhabit environments as different as the Arctic Circle and the Mojave Desert.

Why are frogs going extinct in the 21st century? One might think that frogs are disappearing in areas where many human beings live; however, frogs that live in pristine areas, where no humans live, are also going extinct. One of the first clues about what was killing frogs came from the National Zoo of Washington, D.C. A few years ago, the zookeepers discovered that their population of blue poison-dart frogs was dying off, thanks to an unidentified fungus called Bactrachochytrium dendrobatidis, or Bd, for short. Kolbert learned that the same mysterious fungus, Bd, had killed off most of the golden frogs in El Valle. Bd has also spread to Colombia, Australia, and New Zealand, decimating the frog populations.

The distinction between “mass extinction” and “background extinction” is crucial to understanding the significance of mass extinction. Over millennia, scientists can expect a few species to go extinct—this is “background extinction.” During a mass extinction, however, a huge number of species go extinct in a far shorter time period. One could say that the history of life on Earth consists of “long periods of boredom” (background extinction), punctuated by “panic” (mass extinction).

In the modern era, amphibians are the world’s most endangered class of animal—they seem to be going extinct at a rate 45,000 times higher than the background rate. However, there are many other classes of life, including corals, mollusks, sharks, rays, birds, and mammals, that are going extinct at a roughly comparable speed.

Returning to Bd, Kolbert explores the mystery of why the fungus has spread around the world so quickly. Some argue that humans unintentionally spread Bd around the world in the 1960s, since it was an ingredient in a popular pregnancy test. Others speculate that North American bullfrogs spread Bd to other continents after human beings spread bullfrogs to Asia, Africa, and South America. In either case, the reason for the spread of Bd is the same: human travel, which has produced an “intercontinental reshuffling” that is “unprecedented in the … history of life.”

One day, Kolbert goes with Griffith to explore the El Valle area for frogs. They drive through the rainforest and wait for night to fall (most amphibians are nocturnal). After a while, Griffith spots a San Jose Cochran frog, which he scoops up with gloves, and swabs to test for Bd. Griffith continues, swabbing many different species of frog. He brings two species back to EVACC: a blue-bellied poison frog, and a pale salamander, whose species he was unable to identify. Kolbert realizes that the two creatures Griffith took back to EVACC would never live in the rainforest again—they’d probably die in glass tanks.