chapter 12 Flashcards
the study of populations
Demography
in a population, the number of new individuals that are produced per unit of time minus the number of individuals that die.
Growth rate
): the highest possible per capita growth rate for a population.
Intrinsic growth rate (r):
: appropriate when young individuals are added to the population continuously
Exponential growth
appropriate when young individuals are added to the population at discrete intervals
Geometric growth
a model of population growth in which the population increases continuously at an exponential rate; can be described by the equation:
Exponential growth model
the shape of exponential growth when graphed.
J-shaped curve:
occurs when babies are born continuously (i.e. 12 months out of the year)
Exponential growth
a model of population growth that compares population sizes at regular time intervals.
Geometric growth model
factors that limit population size regardless of the population’s density.
Density independent
factors that affect population size in relation to the population’s density.
Density dependent
when the rate of population growth decreases as population density increases.
Negative density dependence
The most common factors that cause negative density dependence are
limiting resources (e.g., food, nesting sites, physical space).
Crowded populations can also
generate stress, transmit disease, and attract predators.
Populations are often regulated by BOTH
positive & negative density dependence.
the maximum population size that can be supported by the environment.
Carrying capacity (K):
a growth model that describes slowing growth of populations at high densities; it is represented by:
Logistic growth model
the shape of the curve when a population is graphed over time using the logistic growth model
S-shaped curve
the point on a sigmoidal growth curve at which the population has its highest growth rate
Inflection point
