Chapter 5: Populations

The individuals that belong to the same species and live in a given area at a particular time.

All of the populations of organisms within a given area.

The study of factors that cause populations to increase or decrease.

Size, density, distribution, sex ratio, age structure

The total number of individuals within a defined area at a given time.

The number of individuals per unit area at a given time.

A description of how individuals are distributed with respect to one another.

the ratio of males to females in a population

a description of how many individuals fit into particular age categories

the change in the size of a population over time

the maximum potential for growth of a population under ideal circumstances with unlimited resources.

A species that has a high intrinsic growth rate, which often leads to population overshoots and die-offs.

A species with a low intrinsic growth rate, the population increases slowly until it reaches carrying capacity.

Growth whose rate becomes ever more rapid in proportion to the growing total number or size.

A resource that a population cannot live without AND that occurs in quantities lower than the population would require to increase in size.

A growth model that describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment.

The limit of how many individuals in a population the environment can sustain.

logistic growth

they experience frequent boom and bust cycles due to their high intrinsic growth rates.

A factor that influences an individual's probability of survival and reproduction in a manner that depends on the size of the population. Ex. Predation or food availability.

A factor that has the same effect on an individual's probability of survival and reproduction at any population size. Ex. Natural disasters.

organisms spread out evenly. Territorial birds and some plants vying for resources tend to adopt this distribution.

displays no apparent pattern and is typical of many (but not all) plant communities especially forests.

this is typical of animals that live in groups such as meerkats or elephants

the probability that an individual organism will survive.

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

groups of organisms who share a similar age.

A pattern of survival over time in which there is high survival throughout most of the lifespan, but then individuals start to die in large numbers as they approach old age.

A pattern of survival over time in which there is relatively constant decline in survivorship through most of the lifespan.

A pattern of survival over time in which there is low survivorship early in life with few individuals reaching adulthood.

In 1798 Thomas Malthus predicted that human population would surpass the Earth's carrying capacity

The study of human populations and population trends.

Optimum level that would allow most people to live in reasonable comfort and freedom without impairing the ability of the planet to sustain future generations.

The movement of people into a country or region, from another country or region.

The movement of people out of a country or region.

The number of births per 1,000 individuals per year.

The number of deaths per 1,000 individuals per year.

(births + immigration) - (deaths + emigration)

doubling time = 70/growth rate

The number of years it takes a population to double.

true

An estimate of the average number of children that each woman in a population will bear throughout her childbearing years.

the ability to produce an abundance of offspring or new growth; also known as Fertility.

The total fertility rate required to offset the average number of deaths in a population in order to maintain the current population size. Replacement level fertility tends to be higher in developing countries because mortality among young people tends to be higher.

The average number of years that an infant born in a particular year in a particular country can be expected to live.

The number of deaths of children before their first birthday per 1,000 live births.

The number of deaths of children under age 5 per 1,000 live births.

The difference between immigration and emigration in a given year per 1,000 people in a country.

The theory that as a country moves from a subsistence economy to industrialization and increased affluence (wealth) it undergoes a predictable shift in population growth.

Phase 1: Stable or Zero Population Growth (ZPG) because high birth rates and high death rates offset each other.

Phase 2: The death rates drop rapidly, but birth rates do not change. Population growth is greatest at this point.. Rapid population growth because birth rates remain high but death rates decline because of better sanitation, clean drinking water, availability of food and health care.

Phase 3 The birth rates decline and population growth slows. Slowing population growth as the economy and educational system improves and people have fewer children.

a point where birth rates remain high despite lowered death rates.

Phase 4. The population stops growing and sometimes begins to decline. Stabilizing population growth because the relatively high level of affluence & economic development encourage women to delay having children.

The practice of regulating the number or spacing of children through the use of birth control.

An equation used to estimate the impact of the human lifestyle on the environment:

A measure of the value of all products and services produced in one year in one country. Used to measure the affluence of a nation.

a line that crosses an entire area when studying the distribution of a species

Square frame used for sessile organisms to determine species richness, population estimate

Mark animal, return to environment and recapture it

Percent marked/100 x Number Marked / N (Population Estimate)

Take out species, which is not in their best interest, and don't return it

large at the bottom

A triangular shape with a very large and wide base. Looks like rapid but it wider for much longer

Larger at the top

(CBR-CDR)/10

(CBR+Immigration)-(CDR+Emmigration) / 10