Population Basics
What is a population?
A group of organisms of the same species living in the same place at the same time.
Name the rarest dispersion pattern.
Random
Exponential growth produces what shaped curve?
J-shaped
Is a hurricane density-independent or density-dependent?
Density-independent.
What interaction is (+/0)?
Commensalism.
Population ecology studies ____
How and why populations change
Give an example of a clumped dispersion pattern.
Prairie chickens in Illinois (extremely clumped).
The logistic model adds what limiting factor?
Carrying capacity (K).
Give one density-dependent factor.
Competition, predation, disease, parasites.
Predation is what interaction type?
Consumption (+/–).
Name one population attribute.
Size (N), density, dispersion, demography, genetic characteristics.
A Type I survivorship curve has high survivorship for which age group?
Juveniles.
Write the basic growth rate equation.
r = birth rate - death rate.
Density-dependent factors help determine what population value?
Carrying capacity (K).
Give one anti-predator strategy.
Camouflage, schooling, mechanical defenses, chemical defenses, mimicry, escape behavior.
What is generation time?
The average age at which a female gives birth.
Type III survivorship means low survivorship for ________.
Juveniles (high juvenile mortality).
When N approaches K, what happens to r?
r approaches 0.
What happens to reproduction when population density becomes high?
Reproduction decreases (or mortality increases).
Compare Batesian vs Müllerian mimicry.
Batesian = harmless mimics harmful
Müllerian = all harmful, mutual benefit.
Define microevolution.
Change in allele frequencies within a population.
Humans (with healthcare) show which survivorship type?
Type I.
Name one situation where exponential growth occurs.
Colonization of a new habitat; population recovering from catastrophe.
What is an extinction vortex?
Declining small population loses genetic diversity, reducing survival and accelerating decline.
Competition always impacts species in what way?
Negative/negative (-/-).