Generalist Species
Species with a broad ecological niche. They can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions.
Specialist Species
Species with a narrow ecological niche. They may be able to live in only one type of habitat, tolerate only a narrow range of climatic and other environmental conditions, or use only one type or a few types of food.
R-selected Species
Species that reproduce early in their life span and produce large numbers of usually small and short-lived offspring in a short period.
k-selected Species
Species that produce a few, often fairly large offspring but invest a great deal of time and energy to ensure that most of those offspring reach reproductive age.
Biotic Potential
The maximum rate at which a population could increase under ideal conditions
Survivorship curve
Graph showing the number of survivors in different age groups for a particular species.
Cohort
A group of individuals of the same age.
Carrying capacity
Largest number of individuals of a population that a environment can support
Environmental Resistance
All the limiting factors that act together to limit the growth of a population.
Overshoot
The extent to which a population exceeds the carrying capacity of its environment
Exponential Growth
growth whose rate becomes ever more rapid in proportion to the growing total number or size.
Logistic Growth
Growth pattern in which a population's growth rate slows or stops following a period of exponential growth
Age Structure Diagram
graph of the numbers of males and females within different age groups of a population
Population momentum
The propensity for a growing population to continue growing even through fertility is declining because of their young age distribution
Total Fertility Rate
The average number of children born to a woman during her childbearing years.
Replacement Level Fertility
the total fertility rate required to offset the average number of deaths in a population in order to maintain the current population size
Life Expectancy
The average number of years an individual can be expected to live, given current social, economic, and medical conditions.
Infant Mortality rate
the rate of babies per 1,000 that die before their first birthday
Immigration
Movement of individuals into a population
Emigration
movement of individuals out of a population
Crude Birth Rate
The total number of live births in a year for every 1,000 people alive in the society.
Crude Death Rate
The total number of deaths in a year for every 1,000 people alive in the society.
Malthusian theory
The theory that population grows faster than food supply
Density Independent factors
limiting factor that affects all populations in similar ways, regardless of population size
Density Dependent factors
A limiting factor of a population wherein large, dense populations are more strongly affected than small, less crowded ones.
Rule of 70
A method for determining the number of years it will take for some measure to double, given its annual percentage increase.
Demographic Transition
change in a population from high birth and death rates to low birth and death rates
Population
A group of individuals that belong to the same species and live in the same area
Population density
Number of individuals per unit area
Limiting factors
Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.