Population Dynamics Flashcards
What is population density and how is it calculated?
Population density is the number of individuals in a given area. It’s calculated as: Dp = N/A
Where N = population size, A = area.
What does “growth rate” measure and what’s the formula?
It measures the change in population size over time.
gr=ΔN/Δt
What is cgr and how do you calculate it?
It measures the rate of change per individual. cgr=ΔN/N or (N final-N original)/N
What is biotic potential?
The highest possible per capita growth rate under ideal conditions.
What is carrying capacity?
The maximum number of individuals an environment can support over time.
What causes random distribution?
Occurs when resources are evenly spread and individuals don’t strongly interact.
What causes clumped distribution?
Common in nature—caused by patchy resources, social behavior, or protection.
What causes uniform distribution?
Usually due to territorial behavior or competition for space.
What is exponential growth?
A J-shaped curve where the population grows rapidly under ideal conditions.
What is logistic growth?
An S-shaped curve where growth slows as the population reaches carrying capacity.
What is environmental resistance?
Factors that limit population growth, like food shortages, disease, or predation.
What are r-selected species?
Species that reproduce quickly, have short lifespans, and produce many offspring.
What are K-selected species?
Species that reproduce slowly, have long lifespans, and care for few offspring.
What is intraspecific competition?
Competition between members of the same species.
What is interspecific competition?
Competition between different species for the same resources.
What is Gause’s Competitive Exclusion Principle and what does it mean?
Two species competing for the same niche can’t coexist. One will outcompete the other.
What’s a predator-prey cycle?
A repeating cycle where prey increase → predator increase → prey drop → predator drop.
How do producers and consumers affect each other?
Consumers limit producer populations; producers provide food for consumers.
What is protective coloration?
Color patterns that help organisms blend in and avoid predators.
What is Batesian mimicry?
Harmless species mimics a harmful one.
What is Müllerian mimicry?
Two harmful species evolve similar warning signals.
What is mutualism?
Both species benefit (e.g., bees & flowers).
What is commensalism?
One species benefits, the other is unaffected (e.g., remora & shark).
What is parasitism?
One species benefits, the other is harmed (e.g., tapeworm & human).
