Exam 2 - Ecology

Levins's metapopulation model

A population will persist if its patch colonization rate (c) is greater than its patch extinction rate (e).

What happens if the patch extinction rate exceeds the patch colonization rate in Levins's model?

The population goes extinct.

Polar bears

Polar bears are found in the Arctic but not in Antarctica because they are derived from brown bears in the Northern Hemisphere and cannot travel across the tropical areas.

Continental drift

The movement of the Earth's continental plates over geological time, influencing the distribution of species and habitats.

Which population is expected to remain stable in size?

A population with an r of > 0.

Intrinsic rate of increase (r)

The rate typically decreases as a population approaches its carrying capacity due to increased competition and limited resources.

Delayed density independence

Occurs when a population's growth is influenced by density-dependent factors with a lag time.

Carrying capacity

The maximum population size that an environment can sustain indefinitely without being degraded.

Extinction vortex

A phenomenon where a small population loses genetic diversity, increasing the risk of extinction due to inbreeding.

Delayed density dependence

Results in a time lag between changes in population size and the growth rate response to resource limitations.