Unit 3: Populations

Generalist

they have an advantage in changing habitats —> they can recover quicker

Specialist

they are an advantage in habitats that are constant —> they do not do well in changing environments

Fertility Rate

the average total number of children a woman will have in her reproductive years

Replacement Fertility Rate

Typically around 2.1 —> it’s the number of children necessary to replace the death of the parents

Carrying Capacity

max population of a species that can be sustained (eg. food, water, shelter, living space)

Overshoot

when a population exceeds its carrying capacity; typically leads to resource depletion

Fecundity

the ability to produce offspring in abundance (rats = high, humans = low)

Density-Dependent Factors

their effects increase with the population density (eg. access to clean air, food, water, healthcare, habitat, transmission of diseases, etc.)

Density-Independent Factors

they affect the population regardless of the density (eg. natural disasters)

Rule of 70

used for determining population’s doubling time

Demographic Transition

the transition from higher to lower birth & death rates in a country or region as the country develops and moves from a pre/post/mid industrial economic system