Summary and Analysis of The Sixth Extinction: An Unnatural History

Based on the Book by Elizabeth Kolbert

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• Publisher: Worth Books
• Year: 2017
• ISBN:
  9781504044172
• Topic: Biological Sciences
• Subtopic: Environmental Science
• Index: Biological Sciences

So much to read, so little time? This brief overview of The Sixth Extinction tells you what you need to know—before or after you read Elizabeth Kolbert's book. Crafted and edited with care, Worth Books set the standard for quality and give you the tools you need to be a well-informed reader. This short summary and analysis of The Sixth Extinction: An Unnatural History by Elizabeth Kolbert includes:

• Historical context
• Chapter-by-chapter overviews
• Detailed timeline of key events
• Important quotes
• Fascinating trivia
• Glossary of terms
• Supporting material to enhance your understanding of the original work

About The Sixth Extinction by Elizabeth Kolbert: Our planet has endured five events of mass extinction, from centuries of catastrophic heating and cooling to the asteroid that fell to earth and ended the Cretaceous Period. We are currently facing the sixth extinction, and this time the human species is to blame. Elizabeth Kolbert travels the world and meets with scientists who are grappling with the ecological outcomes of human activity. Her Pulitzer Prize–winning modern science classic tells the stories of thirteen different species that have already disappeared or are on the brink of extinction as a result of human activity. A captivating blend of research and historical anecdotes enlightens readers about the unintentional consequences of our behaviors, from climate change and global warming to invasive species and overexploitation. The summary and analysis in this ebook are intended to complement your reading experience and bring you closer to a great work of nonfiction.

Summary

Prologue

About two hundred thousand years ago, a new, not yet named species appeared on the earth in Africa. Although not particularly swift or strong, they were resourceful. Before long, they had crossed rivers, mountain ranges, and oceans without difficulty, adapting to various climates through innovation. More than one hundred thousand years passed. They traveled to faraway lands, bringing a host of germs and animals with them. The ecosystem that greeted them was forced to adapt, but often it was unable to, and other species died. Another one thousand years passed and this species, human beings, inhabited every corner of the globe. They discovered how to use energy from deep in the ground, which alters the atmosphere and the climate. Some animals adjusted by moving—up into the mountains, into deeper water, to the poles—but thousands of species were unable to survive. No other animal has altered life on earth in the way humans have.

The planet has experienced five other periods of enormous change that resulted in mass extinctions. This is the story of the sixth. In the first part of her book, Kolbert discusses creatures that are already extinct and the history that led to our understanding of these mass extinctions. The second part of the book is concerned with the present, and looks at the catastrophic changes happening in the rainforests, the reefs, the mountains, and even our own backyards.

Chapter I: The Sixth Extinction

Kolbert dedicates her first chapter to the modern plight of the golden frog (Atelopes zeteki). Once abundant in Panama’s rainforests, golden frogs now serve as the figurehead for the worldwide endangerment of all amphibians. In 2002, scientists, researchers, and local Panamanians noticed a drastic decline in golden frogs, and by 2004, efforts were underway to preserve the existing population in captivity and to hunt out the cause of their disappearance. Amphibians survived millions of years, dating back to before the dinosaurs, across virtually every habitat, from rainforest to desert to the Arctic Circle. However, their recent disappearance has occurred irrespective of geography and across nearly all species.

As the title suggests, there have been five mass extinctions, the first being 450 million years ago. At the center of the present sixth extinction is the exceptional fact that it is unintentionally caused by one species: us. Kolbert reveals the mysterious amphibian-killer to be a microscopic fungus called Bd, which disrupts normal functioning of the creatures’ skin, resulting in the equivalent of cardiac arrest. Human activity is accountable for the global distribution of Bd, which is now so widespread across the planet that scientists believe it is impossible to repopulate the golden frog and other threatened amphibians in the wild.

Need to Know: The Sixth Extinction opens with the recent and rapid death of amphibians, which is caused by human activity and is occurring at a rate forty-five thousand times higher than the baseline. Once thought nearly impervious to extinction, amphibians are now the world’s most endangered class of animals.

Chapter II: The Mastodon’s Molars

Extinction theory dates back to the eighteenth century and French scientist Georges Cuvier, who famously studied the fossilized remains of the American mastodon. Cuvier gained renown for suggesting extinction as a widespread phenomenon, and for sensationally asserting “the existence of a world previous to ours,” an idea that captivated the Age of Enlightenment and the likes of Thomas Jefferson. While not able to refine a theory of the extinction in his own lifetime, Cuvier did catalog the remains of forty-nine extinct species, including the cave bear, the giant sloth, and the pterodactyl. He also advanced the notion of catastrophism, that a cataclysmic event could cause the end of a species. As for the American mastodon, its demise resulted from humans hunting megafauna during the ice age thirteen thousand years ago.

Need to Know: Kolbert paints a picture of New World intellectuals sitting atop fossils of undiscovered species while still ignorant of their own symbiotic relationship to the natural world. Once Cuvier arrived at the turn of the nineteenth century, the “previous” world of extinct fauna gained much interest and scrutiny.

Chapter III: The Original Penguin

Cuvier’s theory of extinction became overshadowed by its great scientific cousin, Charles Darwin’s theory of evolution. Darwin and his contemporary, geologist Charles Lyell, criticized Cuvier and other catastrophists by asserting the primary cause of extinction to be natural selection, the same gradual mechanism behind evolution—n...

Table of contents

• Title
• Disclaimer
• Contents
• Context
• Overview
• Summary
• Timeline
• Cast of Characters
• Direct Quotes and Analysis
• Trivia
• What’s That Word?
• Critical Response
• About Elizabeth Kolbert
• For Your Information
• Bibliography
• Copyright