NEW Unit 3 APES Miller 7950

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.