Podcast
Questions and Answers
Which of the following is the most accurate distinction between mass extinction and background extinction?
Which of the following is the most accurate distinction between mass extinction and background extinction?
- Mass extinctions occur rapidly and affect a large percentage of species, while background extinctions occur gradually and affect fewer species. (correct)
- Mass extinctions are caused by habitat loss, while background extinctions result from pollution.
- Mass extinctions are reversible, allowing species to recover, whereas background extinctions are permanent.
- Mass extinctions primarily affect marine species, while background extinctions affect terrestrial species.
If the current extinction rate is estimated to be 100 to 1,000 times higher than the natural background rate, what is the primary implication for biodiversity?
If the current extinction rate is estimated to be 100 to 1,000 times higher than the natural background rate, what is the primary implication for biodiversity?
- Ecosystems will become more stable due to the selective removal of weaker species.
- The rate of speciation (the formation of new species) will likely increase to compensate for the losses.
- The overall biomass of the planet will increase as surviving species expand to fill vacant niches.
- The Earth is potentially entering a sixth mass extinction event, characterized by a rapid decline in the number of species. (correct)
Which event resulted in the largest percentage of species extinction?
Which event resulted in the largest percentage of species extinction?
- Permian (correct)
- Ordovician-Silurian
- Cretaceous
- Devonian
Which of the following factors differentiates human-caused extinctions from natural background extinctions?
Which of the following factors differentiates human-caused extinctions from natural background extinctions?
The extinction of the golden toad of Costa Rica, last seen in 1989, is attributed to:
The extinction of the golden toad of Costa Rica, last seen in 1989, is attributed to:
How do fossils primarily aid scientists in understanding extinction events?
How do fossils primarily aid scientists in understanding extinction events?
Which of the following provides the best example of how human land use contributes to increased extinction rates?
Which of the following provides the best example of how human land use contributes to increased extinction rates?
Which of the following scenarios best illustrates how human activities can accelerate the rate of species extinction?
Which of the following scenarios best illustrates how human activities can accelerate the rate of species extinction?
Considering both natural and artificial factors, what is the most likely long-term consequence of continued habitat loss for a highly specialized species with a limited geographic range?
Considering both natural and artificial factors, what is the most likely long-term consequence of continued habitat loss for a highly specialized species with a limited geographic range?
How does the concept of 'background extinction' differ from 'mass extinction' in terms of frequency, causes, and overall impact on biodiversity?
How does the concept of 'background extinction' differ from 'mass extinction' in terms of frequency, causes, and overall impact on biodiversity?
In what way might the extinction of a keystone species influence an ecosystem's structure and stability, potentially triggering further extinctions?
In what way might the extinction of a keystone species influence an ecosystem's structure and stability, potentially triggering further extinctions?
If a population of animals is declining due to hunting, what other factors could compound the problem and push the species towards extinction?
If a population of animals is declining due to hunting, what other factors could compound the problem and push the species towards extinction?
Which of the following factors would make a species MORE vulnerable to extinction?
Which of the following factors would make a species MORE vulnerable to extinction?
What is the primary difference between mass extinction and background extinction?
What is the primary difference between mass extinction and background extinction?
Which of the following is an example of a species that became extinct due to human activities?
Which of the following is an example of a species that became extinct due to human activities?
Flashcards
Extinction
Extinction
The complete disappearance of a species from Earth.
Natural Causes of Extinction
Natural Causes of Extinction
Natural disasters, disease, climate change, and radiation.
Artificial Causes of Extinction
Artificial Causes of Extinction
Habitat loss, invasive species, hunting, and pollution caused by humans.
Examples of Extinct Species
Examples of Extinct Species
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Mass Extinction
Mass Extinction
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Background Extinction
Background Extinction
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Mass extinction
Mass extinction
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Background extinction
Background extinction
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Fossil
Fossil
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Background Extinction Rate
Background Extinction Rate
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Sixth Mass Extinction
Sixth Mass Extinction
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Human-Led Extinction
Human-Led Extinction
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Human Land Use
Human Land Use
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Study Notes
- Extinction occurs when a species no longer exists.
- Extinction can be caused by natural or artificial processes.
- The likelihood of extinction depends on the makeup of the species and their living conditions.
Causes of Extinction
- Natural causes include natural disasters, disease, climate change, sea levels, and radiation.
- Human activities pose the biggest danger to most species.
- Human involvement examples include habitat loss, invasive species, hunting/poaching, and pollution.
Examples of Extinct Species
- Dodo Bird: Hunting/Disease from Invasive Species.
- Wooly Mammoth: Hunting/Climate Change.
- Eurasian Aurochs: Hunting/Disease.
- Sabre-tooth Cat: Extinction of Prey/Climate Change.
- Steller's Sea Cow: Hunting.
Types of Extinction
- Mass extinction and background extinction are the two main types.
Mass Extinction
- Mass extinction is a rare phenomenon caused by a major catastrophe.
- Mass extinctions are sudden and sweeping events without human involvement.
- A mass extinction is defined as when over 50% of plant and animal life dies.
- Fossils help determine dates and effects of mass extinctions.
- The Cretaceous extinction is the most recent and studied mass extinction.
Past Mass Extinctions:
- Ordovician-Silurian: 85% of species died.
- Devonian: 75% of species died.
- Permian ("The Great Dying"): 95% of species died.
- Triassic: 80% of species died.
- Cretaceous: 78% of species died.
Background Extinction Definition
- Background extinction is the natural elimination of species over a long period.
- It occurs due to natural population decline, reproduction failure, or inability to support themselves in the food chain.
- Climate change and population control are significant factors in background extinction.
Examples:
- The golden toad of Costa Rica believed to be extinct, last seen in 1989, because of rising temperatures and reduced rainfall
- The blue pigeon lived on the island of Mauritius, but became extinct in 1835 through predation by macaque monkeys competing for the same prey
Extinction Rates
- The natural extinction rate is one species per million species per year.
- Current extinction rates are estimated to be 100 to 1,000 times higher than the natural rate.
- An estimated 200 to 2,000 species go extinct each year.
Human Impact on Extinction
- Some scientists believe Earth is heading towards a sixth mass extinction due to human influence and climate change.
- In recent years extinction has been due to the effects of humans on the Earth.
- Pollution, resource depletion, deforestation, habitat loss, and overhunting are major reasons for extinction.
- This "human-led" extinction could be considered a third type of extinction.
Statistics on Human Land Use:
- Deforestation takes away the habitat of other species and places a greater strain on the Earth.
- 75% of land has been adapted for human use.
- 33% of land is used for farming and agriculture.
- 66% of oceans have been used for human development.
- 75% of freshwater resources have been used.
- 25% of pollution comes from greenhouse gas emissions.
Global Warming and Species:
- 5% of species would be affected if the Earth heated 2 degrees Celsius.
- 16% of species face extinction with the current global warming trajectory.
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Description
Explore the causes and types of species extinction, including natural disasters, human activities, mass extinctions, and background extinctions. Learn about examples like the Dodo bird, Wooly Mammoth, and Sabre-tooth Cat. Understand the factors that influence a species' vulnerability to extinction.
