Unit 3 Population Vocabulary

Age Structure (of a population) - Structure of a population divided into groups by age.

Sometimes the groupsrepresent the actual number of each age in the population or proportion of the population of each age.

Age Structure Diagram - A representation of the number of individuals in each age group in a population.

Baby Boom - The jump in birthrates in the years after World War Two. "Baby boomers" are the generation born between 1945 and about 1960. In this period, more than 65 million children were born. They grew up  in a generally prosperous period in American life, but also experienced as teenagers the uncertainties and conflicts of the 1950s and 1960s.

Birth Rate - The rate at which births occur in a population, measured either as the number of individuals born per unit of

time compared with the population.

Carrying Capacity - The maximum abundance of a population or species that can be maintained by a habitat or ecosystem without degrading the ability of that habitat or ecosystem to maintain that abundance in the future.

Crude Birth Rate - The annual number of live births per 1000 population, without regard to age or sex composition.

Crude Death Rate - The annual number of deaths per 1000 population, without regard to age or sex composition.

Death rate - The rate at which deaths occur in a population, measured either as the number of individuals dying per unit time or as the percentage of a population dying per unit time.

Demographic Transition - The pattern of change in birth and death rates as a country is transformed from undeveloped to developed. There are three stages: (1) in an undeveloped country birth and death rates are high, and the growth rate is low; (2) the death rate decreases, but the birthrate remains high and the growth rate is high; (3) the birthrate drops toward the death rate and the growth rate therefore decreases.

Demography - The study of populations, especially their patterns in space and time.

Developed (less developed) Nations - A less developed nation is a nation with a low income average, a relatively backwards infrastructure and a poor human development index when compared to the global norm.

Developed (more developed) Nations - A more developed nation is a nation that is technologically advanced and that enjoys a relatively high standard of living.

Doubling Time - The time necessary for a quantity of whatever is being measured to double.

Ecological Justification (for the conservation of nature) - An argument for the conservation of nature on the grounds that a species, an ecological community, an ecosystem, or the Earth's biosphere provides specific functions necessary to the persistence of our life or of benefit to life. The ability of trees in forests to remove carbon dioxide produced in burning fossil fuels is such a public benefit and an argument for maintaining large areas of forests.

Emigration - The migration of people out of a country.

Exponential Growth - growth in which the rate of increase is a constant percentage of the current size; that is, the growth

occurs at a constant rate per time period.

Family Planning - Controlling reproduction; planning the timing of birth and having as many babies as are wanted and can be supported.

Famine - A sever shortage of food.

Growth Rate - The net increase in some factor per unit time.

Immigration - The migration of people into a country.

Infant Mortality Rate - The probability of dying between birth and exactly one year of age, expressed per 1,000 live births.

J-Curve - A type of graph predicting the exponential growth of a population.

Kwashiorkor - Lack of sufficient protein in the diet, which leads to a failure of neural development in infants and therefore to learning disabilities.

Life Expectancy - The estimated average number of years that an individual of a specific age can expect to live.

Limiting Factor - The single requirement for growth available in the least supply in comparison to the need of an organism. Originally applied to crops but now often applied to any species.

Linear Growth - population growth which is modeled by adding a fixed amount each time period

Logistic Growth Curve - The S-shaped growth curve that is generated by the logistic growth equation. In the logistic, a small population grows rapidly, but the growth rate slows down, and the population eventually reaches a constant size.

Malnutrition (Malnourishment) - The lack of specific components of food, such as proteins, vitamins, or essential chemical elements

Marasmus - Progressive emaciation (to become extremely thin) caused by a lack of protein and calories.

Migration - The movement of an individual, population, or species from one habitat to another or more simply from one geographic area to another.

Moral Justification (for the conservation of nature) - An argument for the conservation of nature on the grounds that aspects of the environment have a right to exist, independent of human desires, and that it is our moral obligation to allow them to continue or to help them persist.

Mortality - A measure of deaths in a given population, location, or other grouping of interest. Overnutrition (Overnourishment) - Receiving more than enough calories to move or work from food.

Per Capita - Per person.

Population - A group of individuals of the same species living in the same area or interbreeding and sharing genetic information.

Population Dynamics - The study of changes in population sizes and the causes of these changes.

Population Momentum (or lag effect) - The continued growth of a population that occurs after achievement of replacement level fertility is reached.

Replacement-Level Fertility - Fertility rate required for the population to remain a constant size.

Survivorship Curve - Survivorship curves are the graphs of a species survival rate in a given ecosystem.

Type I survivorship curves - are for species that have a high survival rate of the young, live out most of their expected life span and die in old age. Humans are a good example of a species with a Type I survivorship curve.

Type Il survivorship curves - are for species that have a relatively constant death rate throughout their life span. Death could be due to hunting or diseases. Examples of species exhibiting a Type Il survivorship curve are coral, squirrels, honey bees and many reptiles.

Type Ill survivorship curves - are found in species that have many young, most of which die very early in their life. Plants, oysters and sea urchins are examples of species that have Type Ill survivorship curves.

The Rule of 70 - states that to find the doubling time of a quantity growing at a given annual percentage rate, divide the percentage number into 70 to obtain the approximate number of years required to double. For example, at a 10% annual growth rate, doubling time is 70 / 10 = 7 years.

Total Fertility Rate - Average number of children expected to be born to a woman during her lifetime.

Urban Sprawl - The unplanned expansion of development over a large area.

Utilitarian Justification (for the conservation of nature) - An argument for the conservation of nature on the grounds that the environment, an ecosystem, habitat, or species, provides individuals with direct economic benefit or is directly necessary to their survival.

Zero Population Growth - A population in which the number of births equals the number of deaths so that there is no net change in the size of the population.