the field of biology that focuses on the interactions among organisms as well as between them and their environent
all of the idividuals of a species within a given area.
the size of more mobile or inconspicuous species can be estimated by this.
high densities of individuals in certain resource-rich areas and low densities elsewhere.
rivers and coastlines
clumped distributions shown
no compelling factor is actively bringing individuals together or pushing them apart.
growth that occurs in proportion to the current total.
exponential growth results in this
quarter million people
added to population every day
the percent change in a population size over a single year. Growth rate is a function of the birth rate of the population minus the death rate.
the period when birth rates are dropping toward lowered death rates
the vast majority of future population growth will occur within populations in the less-developed world, but these countries are also where the vast majory of food crises are occurring!
the maximum population that can be supported indefinitely in a given environment is known as the environments carrying capacity.
population-limiting factors that increase in intensity as a population "increases" in size. density-dependent factors include limited food supply, increased risk of infectious disease, and an increase in toxic-waste levels.
Human population growth rates were at their highest in the early 1960's, about 2.1% yearly, but they have since declined to 1.2%.
many essential supplies that sustain the current population; meaning they are a one-time stock and cannot be easily replaced.
human ingenuity has helped populations circumvent seemingly fixed natural resources.
the death rate soars while the birth rate plummits.
a lag between the time when humans reduce birth rates and when population growth actually begins to show.
a summary of the numbers and proporations of individuals of each sex and each ae group.