All flashcards
Flashcard 1: Identify the most likely result of a population bottleneck on future adaptability.
Answer: Reduced adaptability due to lower genetic variation. Fewer alleles limit evolutionary responses to future challenges.
Flashcard 2: What is the founder effect and how can it change biodiversity within a population?
Answer: A new population starts from few individuals, altering allele frequencies. Random sampling of alleles creates genetic differences from source.
Flashcard 3: What is a population bottleneck and its effect on genetic diversity?
Answer: A sharp N reduction that decreases genetic variation. Surviving individuals carry only a subset of original alleles.
Flashcard 4: State the per capita growth rate definition using r in population ecology.
Answer: r is the per-individual rate of increase (births minus deaths per capita). Birth and death rates determine net population change.
Flashcard 5: Identify whether regulation is density-independent: a hurricane reduces all populations in a region.
Answer: Density-independent. External forces affect populations regardless of their size.
Flashcard 6: What is the typical effect of higher biodiversity on ecosystem stability?
Answer: Higher biodiversity generally increases stability and resilience. Diverse communities buffer against environmental fluctuations.
Flashcard 7: What is logistic growth in population dynamics?
Answer: Growth slows as N approaches K; an S-shaped curve. Environmental resistance slows growth near carrying capacity.
Flashcard 8: What is biodiversity, as used in ecology when comparing communities?
Answer: The variety of life across genes, species, and ecosystems in an area. Encompasses genetic, species, and ecosystem variety in a defined region.
Flashcard 9: What is competitive exclusion in population ecology?
Answer: Two species with identical niches cannot stably coexist. Complete niche overlap leads to competitive displacement.
Flashcard 10: What is niche partitioning and how does it relate to biodiversity?
Answer: Species use different resources; it reduces competition and supports diversity. Resource specialization allows coexistence and maintains diversity.
Flashcard 11: What is the “insurance effect” of biodiversity on population dynamics?
Answer: Multiple species can maintain function when one species declines. Functional redundancy maintains ecosystem services when species decline.
Flashcard 12: What is the diversity–stability hypothesis in one sentence?
Answer: More diverse ecosystems tend to show more stable functioning over time. More species provide functional backup during disturbances.
Flashcard 13: What is the typical effect of higher biodiversity on ecosystem stability?
Answer: Higher biodiversity generally increases stability and resilience. Diverse communities buffer against environmental fluctuations.
Flashcard 14: What is carrying capacity (K) of an environment?
Answer: The maximum population size the environment can sustainably support. Environmental capacity determines long-term population stability.
Flashcard 15: What is a limiting resource in population dynamics?
Answer: A resource that restricts population growth when scarce. Essential resources like food or space become bottlenecks.
Flashcard 16: What is population density in ecology?
Answer: Number of individuals per unit area or volume. Measures crowding intensity in a given space.
Flashcard 17: What is population size (N) in population dynamics?
Answer: The total number of individuals in a population. Fundamental measure for tracking population changes over time.
Flashcard 18: What is species evenness in a community?
Answer: How evenly individuals are distributed among species. Measures whether species abundances are balanced or skewed.
Flashcard 19: What is species richness in a community?
Answer: The number of different species present. Counts distinct species without considering their relative abundances.
Flashcard 20: Identify the relationship: if biodiversity increases, what usually happens to variation in total ecosystem biomass over time?
Answer: Variation usually decreases (biomass becomes more stable). Portfolio effects from multiple species reduce temporal variability.
Flashcard 21: What is density-independent regulation of population size?
Answer: Population limits act regardless of density (e.g., drought, storms). Environmental factors affect all individuals equally.
Flashcard 22: What is the direct relationship between biodiversity and disease spread risk?
Answer: Lower biodiversity can increase disease transmission in some systems. Fewer hosts can concentrate disease transmission pathways.
Flashcard 23: What is an extinction vortex in small populations?
Answer: A reinforcing cycle of small N, low diversity, and rising extinction risk. Multiple factors compound to accelerate population decline.
Flashcard 24: What is K-selected life history strategy in population dynamics?
Answer: Lower reproduction, later maturity, higher parental care; stable near K. Emphasizes survival and competitive ability in stable environments.
Flashcard 25: Identify the relationship between biodiversity loss and food web complexity.
Answer: Biodiversity loss typically simplifies food webs and reduces redundancy. Fewer species create simpler, less stable food networks.
Flashcard 26: State the per capita growth rate definition using r in population ecology.
Answer: r is the per-individual rate of increase (births minus deaths per capita). Birth and death rates determine net population change.
Flashcard 27: What is logistic growth in population dynamics?
Answer: Growth slows as N approaches K; an S-shaped curve. Environmental resistance slows growth near carrying capacity.
Flashcard 28: What is exponential growth in population dynamics?
Answer: Growth proportional to N; a J-shaped increase when resources are abundant. Unlimited resources allow maximum reproductive potential.
Flashcard 29: Choose the correct link: if pollinator diversity declines, what happens to plant reproduction rates?
Answer: Plant reproduction rates often decrease. Pollinator loss directly reduces plant reproductive success.
Flashcard 30: Identify the most likely result of a population bottleneck on future adaptability.
Answer: Reduced adaptability due to lower genetic variation. Fewer alleles limit evolutionary responses to future challenges.