Population Basics
All the individuals of a species that live together in an area.
What is a population?
The three key features of populations.
What are size, density, and dispersion?
Population growth where numbers increase at a constant rate; shown as a J-curve.
What is exponential growth?
A factor that decreases growth when food becomes scarce.
What is a limited food supply?
Species that reproduce quickly, have many young, and require little parental care. (Flies, Ticks, Cockroaches)
What are r-strategists?
The statistical study of populations, allows predictions to be made about how a population will change
What is demography?
Births minus deaths in a population equals this.
What is the growth rate
Growth that levels off as the carrying capacity is reached, shown as an S-curve.
What is logistic growth?
A buildup of this can increase mortality in densely populated areas.
What are toxic wastes?
Species with long lifespans, few offspring, and lots of parental care. (Humans, Giraffes, Rhinos)
What are K-strategists?
The number of individuals per unit area.
What is population density?
Movement of individuals into a population.
What is immigration?
The maximum population size an environment can support.
What is the carrying capacity (K)?
When more predators appear, as prey populations grow.
What is predation?
The distribution of males and females in each age group.
What is age distribution?
The spacing of organisms relative to each other (clumped, uniform, random).
What is dispersion?
Biotic factors like disease, competition, or parasites that increase with population size.
What are density-dependent factors
Name one method scientists use to measure population size.
What is sampling, or the mark-recapture method?
A population overshooting its carrying capacity often leads to this.
What is a population crash?
The human population growth curve continues to rise due to advancements in agriculture, industry, and technology. What type of curve do we see?
What is a J-curve
A species’ specific role or “job” in its environment.
What is a niche?
Abiotic factors, such as weather or temperature, affect populations regardless of their density.
What are density-independent factors?
A population cycle of rapid increases followed by sharp declines. (Snow Hare and Lynx)
What are booms and busts?
The formula for population growth includes births, deaths, immigration, and emigration.
(Birth + Immigration) − (Death + Emigration)
Name one major human advancement that has reduced death rates and fueled population growth.
What are the agricultural revolution, industrial-medical revolution, or technological advances?