Ch. 5 Vocab Flashcards
(21 cards)
The number of individuals that can be found per unit area
Population density
Describes the way individuals are spaced out across their range
Population distribution
Number of males and females of each age in a population
Age structure
Movement of individuals into an area occupied by an existing population
Immigration
Movement of individuals out of an area
Emigration
Growth pattern in which the individuals reproduce at a constant rate. A J shaped graph.
Exponential growth
Growth pattern in which a population’s growth slows down and then stops following a period of exponential growth. An S shaped graph.
Logistic growth
The maximum number of individuals of a particular species that a particular environment can support. Determined by limiting factors.
Carrying capacity
Any factor that causes population growth to decrease. Can be abiotic or biotic.
Limiting factor
Limiting factors determined by the carrying capacity of an environment for a species. Includes; competition, stress from overcrowding, predation, disease, parasitism, and herbivory.
Density-dependent limiting factor
Factors that affect all populations regardless of the population size and density. Including natural disasters.
Density-independent limiting factor
The scientific study of human populations
Demography
A dramatic change from high birth rates and death rates to low birth rates and low death rates.
Demographic transition
The population begins to grow rapidly and reproduce exponentially. There’s an increase in population size and rapid growth rate. (Exponential growth)
Phase 1 of Logistic Growth
The rate of population growth slows down; the population is still increasing, just at a much slower rate
Stage 2 of Logistic Growth
The population growth stops/drops to zero. The population’s size levels off at carrying capacity where it could stay forever.
Phase 3 of Logistic Growth
Carrying capacity can be pushed so low due to limiting factors that it may cause ________
Extinction
Human populations, like other populations, tend to _______
Increase
Why do population growth rates differ among countries?
Birth rates, death rates, and the age structure of the population
How does the environment affect human population changes?
They have profoundly altered human deaths
What are Malthus’ predictions about human population growth?
Uncontrolled population growth would lead to a depletion of resources, increased pollution, overcrowding, and increased unemployment
