Extinction Topic

Extinction Topic

Which concept describes positive feedbacks between biotic and abiotic factors driving extinction?

“Extinction vortex” for which concept describes positive feedbacks between biotic and abiotic factors driving extinction. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. The remaining alternatives—“Habitat fragmentation”, “Genetic drift”, “Environmental bottleneck”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Which of the following is least associated with extinction risk?

“Generalist species” for which of the following is least associated with extinction risk. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. The remaining alternatives—“Narrow niche width”, “Top predator status”, “Habitat fragmentation”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Introduction of predators like rats and cats most affects:

“Island birds” for introduction of predators like rats and cats most affects. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. The remaining alternatives—“Marine mammals”, “Terrestrial reptiles”, “Amphibians”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Extinction due to human activity is called:

“Anthropogenic extinction” for extinction due to human activity is called. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Human-driven habitat conversion, exploitation, introduced enemies, pollution, and climate change often interact rather than acting independently. Traits such as slow reproduction or ecological specialization can magnify vulnerability. The remaining alternatives—“Mass extinction”, “Demographic extinction”, “Natural extinction”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

High population size variability:

“Increases extinction risk” for high population size variability. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. The remaining alternatives—“Reduces extinction risk”, “Maintains stability”, “Is unrelated to extinction”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Habitat destruction causes what percent of extinctions?

“0.36” for habitat destruction causes what percent of extinctions. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. The remaining alternatives—“0.23”, “0.434”, “0.38”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Which is a density-independent cause of extinction?

“Catastrophic climatic event” for which is a density-independent cause of extinction. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. The remaining alternatives—“Disease”, “Competition”, “Predation”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Which of the following does NOT increase extinction probability?

The keyed exception is “Broad geographic distribution.” In the context of which of the following does not increase extinction probability, that statement differs from the governing ecological pattern and must be evaluated against the mechanism rather than accepted from wording alone. Human-driven habitat conversion, exploitation, introduced enemies, pollution, and climate change often interact rather than acting independently. Traits such as slow reproduction or ecological specialization can magnify vulnerability. The remaining alternatives—“High degree of specialization”, “High trophic status”, “Small population size”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Poor dispersers in fragmented habitats:

“Are at higher extinction risk” for poor dispersers in fragmented habitats. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. The remaining alternatives—“Adapt well to new environments”, “Easily migrate”, “Show higher reproductive rate”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Human-driven habitat conversion, exploitation, introduced enemies, pollution, and climate change often interact rather than acting independently. Traits such as slow reproduction or ecological specialization can magnify vulnerability. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

An organism with low variability in population size is:

“Less extinction prone” for an organism with low variability in population size is. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. The remaining alternatives—“Highly extinction prone”, “Genetically unstable”, “Unable to adapt”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Human-driven habitat conversion, exploitation, introduced enemies, pollution, and climate change often interact rather than acting independently. Traits such as slow reproduction or ecological specialization can magnify vulnerability. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Which of the following is most vulnerable to extinction?

“High variability in population size” for which of the following is most vulnerable to extinction. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. The mechanism should be evaluated across both local and global scales. Local disappearance can be reversed by recolonization, whereas global extinction is irreversible and requires the loss of every surviving population. The remaining alternatives—“Wide geographic range”, “Low trophic level”, “High dispersal ability”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Human-driven habitat conversion, exploitation, introduced enemies, pollution, and climate change often interact rather than acting independently. Traits such as slow reproduction or ecological specialization can magnify vulnerability. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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Extinction Topic

Which extinct species is linked to human hunting and invasive species on islands?

“Dodo” for which extinct species is linked to human hunting and invasive species on islands. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. At equilibrium, species identities can continue to turn over even when richness is approximately stable. The model predicts a balance of rates, not an absence of colonization or extinction. The remaining alternatives—“Moa”, “Pyrenean Ibex”, “Passenger Pigeon”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Island biogeography explains species richness as a dynamic balance between immigration and extinction. Immigration generally declines as an island fills with species, whereas extinction rises as more species divide finite area and maintain smaller populations. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates.

Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7

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