10 public questions tagged with this topic.
Human activities such as habitat loss and fragmentation, overexploitation, alien species invasions, and co-extinctions have greatly accelerated extinction rates.
Ref: NCERT Class 12 Biology Chapter 13: Biodiversity and Conservation Loss of Biodiversity - Causes - Habitat Loss Overexploitation
Human activities such as habitat loss and fragmentation, overexploitation, alien species invasions, and co-extinctions have greatly accelerated species extinction.
Ref: NCERT Class 12 Biology Chapter 13: Biodiversity and Conservation Loss of Biodiversity - Causes - Habitat Loss Overexploitation
Human activities have accelerated extinction rates to about 100–1000 times the natural background rate.
Ref: NCERT Class 12 Biology Chapter 13: Biodiversity and Conservation Loss of Biodiversity - Causes - Habitat Loss Overexploitation
Habitat loss and fragmentation, overexploitation, alien species invasions, and co-extinctions are the major causes of biodiversity loss described in NCERT.
Ref: NCERT Class 12 Biology Chapter 13: Biodiversity and Conservation Loss of Biodiversity - Causes - Habitat Loss Overexploitation
According to NCERT, the present extinction rate is 100–1000 times the natural background rate because of habitat loss and fragmentation, overexploitation, alien species invasions, and co-extinctions.
Ref: NCERT Class 12 Biology Chapter 13: Biodiversity and Conservation Loss of Biodiversity - Causes - Habitat Loss Overexploitation
“Small, far from mainland” for which island condition is likely to have high species extinction. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. 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. The remaining alternatives—“Large, near mainland”, “Small, near mainland”, “Large, far from mainland”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Larger islands usually support more habitats and larger populations, lowering extinction risk; less isolated islands receive colonists more readily and may experience rescue effects. These mechanisms also apply to habitat fragments that function as ecological islands. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.
Ref: Biogeography, Lomolino et al., 5th Ed., Ch. 1-4
“Island area” for according to island biogeography theory, what influences extinction rate significantly. 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—“Island color”, “Island altitude”, “Island shape”—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. 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: Biogeography, Lomolino et al., 5th Ed., Ch. 1-4
“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
“Gilpin and Soulé” for the extinction vortex was first described by. 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—“Darwin and Wallace”, “Frankham and Soulé”, “Stephens and Bradshaw”—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. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation. 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
“Habitat destruction and introduced species” for which is the major cause of species extinction globally. 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—“Natural disasters”, “High genetic diversity”, “Overpopulation of prey”—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.
Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7
