The Sixth Extinction Chapter 1 Flashcards

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Questions and Answers

Who is the author?

Elizabeth Kolbert

What is the setting of Chapter One?

The Panamanian city of El Valle de Antón located in a volcanic crater.

How did Kolbert hear about the frogs?

Nature magazine for children, then an article by David Wake and Vance Vredenburg.

When was the first mass extinction?

Late Ordovician period (450 million years ago) Signup and view all the answers

What is the scientific name for the golden frog?

Atelopus zeteki Signup and view all the answers

What facility is located in El Valle, and what is their goal?

EVACC (El Valle Amphibian Conservation Center). They aim to preserve and protect amphibian species. Signup and view all the answers

Who is EVACC's director?

Edgardo Griffith Signup and view all the answers

Why is it shocking that frog species are going extinct?

Because amphibians are the planet's great survivors, having existed for around 400 million years. Signup and view all the answers

Amphibians have adapted to conditions on every continent except _____

Antarctica Signup and view all the answers

How many species of amphibians have been identified?

More than 7000 species Signup and view all the answers

Were the frogs dying off only in populated areas?

False Signup and view all the answers

What was the first clue to figuring out the golden frog mystery?

In the National Zoo, blue poison dart frogs were dying off due to a chytrid fungus. Signup and view all the answers

What is the name of the microorganism that is killing amphibians?

Bd, a chytrid fungus (Batrachochytrium dendrobatidis) Signup and view all the answers

What does the term 'amphibian' mean in Greek?

Double life Signup and view all the answers

What does 'batrachos' mean in Greek?

Frog Signup and view all the answers

How does Bd kill amphibians?

It interferes with their ability to take up critical electrolytes through their skin. Signup and view all the answers

Where has the chytrid fungus spread?

Colombia, South America, Australia, New Zealand, Caribbean, Italy, Spain, Switzerland, France, US. Signup and view all the answers

What is background extinction?

A gradual process of a species becoming extinct over geological epochs. Signup and view all the answers

What is the background extinction rate for mammals?

0.25 per million species-years Signup and view all the answers

What are mass extinctions?

Events that eliminate a significant proportion of the world's biota in a geologically insignificant amount of time. Signup and view all the answers

How much higher is the amphibian's extinction rate compared to the normal background rate?

About 45000 times Signup and view all the answers

What other classes of life are going extinct at a comparable rate to amphibians?

Birds, sharks, mammals, coral reefs Signup and view all the answers

How has Bd been able to spread around the world?

Through the 'out of Africa' theory and 'frog leg soup' theory, involving human commerce. Signup and view all the answers

Study Notes

Author and Setting

Elizabeth Kolbert is the author of "The Sixth Extinction."
Chapter one is set in El Valle de Antón, a Panamanian city within a volcanic crater, formerly home to panamanian golden frogs, now extinct in the area.

Discovery of the Frog Crisis

Kolbert learned of the golden frogs through a children's nature magazine and an article by David Wake and Vance Vredenburg discussing the concept of the sixth extinction.

Extinction Events

The first mass extinction occurred during the late Ordovician period, approximately 450 million years ago.
The most destructive extinction event was at the end of the Permian period around 250 million years ago.
The most recent notable mass extinction occurred at the end of the Cretaceous period, which led to the demise of the dinosaurs.

Golden Frog Details

The scientific name for the golden frog is Atelopus zeteki.
The El Valle Amphibian Conservation Center (EVACC) aims to preserve remaining amphibian species in the Panamanian rainforest, particularly focusing on the golden frogs.

Conservation Insights

Edgardo Griffith, EVACC’s director, warns that many species are facing extinction before being discovered.
Amphibians are historically seen as survivors, with ancestors emerging around 400 million years ago and modern orders evolving roughly 250 million years ago.

Amphibian Distribution

Amphibians are found on every continent except Antarctica and there are over 7,000 identified species.
Most amphibians thrive in tropical rainforests, but some also inhabit deserts and regions above the Arctic Circle.

Widespread Decline

The decline of frog populations is evident in both populated and pristine, untouched environments.

Initial Clue to Extinction Mystery

The initial indication of the golden frog's plight arose from blue poison dart frogs dying in the National Zoo, leading to findings of chytrid fungus on their skin.

Chytrid Fungus Impact

The fatal microorganism known as Bd (Batrachochytrium dendrobatidis) disrupts amphibians' ability to absorb essential electrolytes, leading to fatal heart attacks.

Global Spread of Bd

Chytrid fungus has disseminated across various regions, including Colombia, Australia, and several European countries, and does not require frogs to survive.

Extinction Rates

Background extinction is the slow, natural process through which species become extinct over extensive geological epochs.
The background extinction rate for mammals is approximately 0.25 per million species-years, translating to about one extinction every 700 years. For amphibians, it is one every 1,000 years.

Mass Extinction Characteristics

Mass extinctions rapidly eliminate a significant portion of global biodiversity in geologically brief periods, resembling sudden, violent reductions in the tree of life.

Present Extinction Crisis

The current amphibian extinction rate is about 45,000 times higher than the normal background rate, indicating severe ecological distress.

Other Affected Species

Birds, sharks, mammals, and coral reefs are also experiencing extinction at rates comparable to those of amphibians.

Human Influence on Extinction Spread

The "out of Africa" theory suggests that infected African clawed frogs, used for pregnancy tests, helped disperse Bd globally without succumbing to the fungus themselves.
The "frog leg soup" theory posits that North American bullfrogs, shipped for food, were carriers of the fungus, inadvertently facilitating its global spread.
Both theories highlight how human actions disrupt ecological balance, accelerating mass extinction events.

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Description

Test your knowledge of Chapter 1 from 'The Sixth Extinction' by Elizabeth Kolbert. Dive into the setting of El Valle de Antón and learn about the disappearance of the Panamanian golden frogs. These flashcards will help reinforce key concepts and details from this impactful chapter.