Populations- Biology

Population

A group of individuals that belong to the same species and live in the same area

Population size

the number of individuals in a population

population density

Number of individuals per unit area

Dispersion

the pattern of spacing among individuals within the boundaries of the population

birth rate

the number of births in a population in a certain amount of time

mortality rate

death rate

life expectancy

A figure indicating how long, on average, a person may be expected to live

age structure

number of males and females of each age in a population

survivorship curve

a graph that represents the distinct patterns of species survival as a function of age

growth rate

Rate of increase or decrease of a population

Immigration

Movement of individuals into a population

Emigration

movement of individuals out of an area

exponential growth

Growth pattern in which the individuals in a population reproduce at a constant rate

Limiting factors

Conditions in the environment that put limits on where an organism can live

logistic model of population growth

model for growth of a population limited by density-dependent factors; numbers increase exponentially at first, then the growth rate slows and population size levels off at carrying capacity

carrying capacity

Largest number of individuals of a population that a environment can support

density dependent factors

limiting factor that depends on population size

density-independent limiting factor

limiting factor that affects all populations in similar ways, regardless of population size

Inbreeding

Continued breeding of individuals with similar characteristics

Hunter-gathering

A way of living where people hunt animals and gather plants to survive.

Agricultural Revolution

The time when human beings first domesticated plants and animals and no longer relied entirely on hunting and gathering

developed countries

countries with strong economies and a high quality of life

developing countries

countries with less productive economies and a lower quality of life

demographic transition

change in a population from high birth and death rates to low birth and death rates