the study of populations
What can Demography include?
-Historical size and makeup (age
What does it mean by historical size and makeup?
So how many teenagers vs adults vs elderly, etc.
What does it mean by Economics?
So how many poor vs middle class vs rich, etc.
What does it mean by social structure?
So how many teachers vs military vs bankers vs students, etc.
What are two general categories for countries which describe their growth rates?
Developed Countries and Developing Countries
What are characteristics of developed countires?
-Higher average incomes
-Slower population growth
-Diverse industrial economies
-Stronger social support systems
What are some examples of developed countreis?
US, Canada, Australia, United Kingdom, France, etc.
What are characteristics of developing countries?
-Lower average incomes
-Simple/agricultural based economies
-Rapid population growth
-Tend to need more foreign aid
What are some examples of developing countries?
Ex.) Honduras, India, Kenya, etc.
What has happened to the world population over time?
What are the factors affecting global human population?
Human population growth has accelerated
(_______) in the last few centuries.
The main reasons for this growth were
improvements in ____ and increases in
, which accompanied the
_____ and _____ revolutions.
Who tries to predict population trends using data?
What data do demographers use?
What is an Age Structure?
graphically represents the data in a double-sided bar graph
The ____ side of the diagram is particularly important in understanding future growth.
Why is it import to understand future growth of females?
This is because fertility is largely controlled by the number of females in their reproductive years (roughly ages 15 -40).
The population/age structure of the__________ represents that of a stable (or nearly stable) population. (pyramid is more _____)
Death rate per individual
What has led to a profound change in the population growth curve in the developed world?
The combination of decreasing death rate due to the march of progress in sanitation and medicine, coupled with the decrease in birth rate due to changes in the economies
The percentage of members of a group that are likely to survive to any given age.
# of babies born each year/1,000 women in a population
What is an example of fertility rates?
baby boom was a period of high fertility, followed by the baby bust
avg # children need to have to replace the parents = _____
Fertility is largely controlled by ____ and by _____.
The high fertility of the developing world can be partially explained by the large number of hands needed to perform low-technology agricultural tasks.
As technology improves, parents realize that having more children decreases rather than increases their standard of living.
A dramatic example of this effect occurred in _____, where, as soon as parents realized that future economic status was linked to the secondary schooling (which is expensive in Thailand), the fertility rate dropped from about __ to __ in a decade!
6 to 2
immigration (_____) -vs-emigration (_____)
people are coming in
people are exiting/leaving
Average number of years a person is likely to live
In the demographic transition model, countries progress through __ stages of chance in birth rates, death rates, and population size.
What are the 4 stages?
Low growth rate, stability of death and births
Most of the world in this condition until ~1700, then scientific and industrial revolution began.
Population explosion as death rate declines (as hygiene, nutrition, and education improve) and birth rates continue high, so population grows very fast.
Stability at a much higher population level
Population grows slow because ____ _____ ____, so population _____ but much higher than before. (most countries ______ their population during transition in 20thcentury)
Birth rate decreases
Birth rate drops below replacement level (negative growth rate), so population decreases
When a growing population uses ____ faster than they can be ____, the resources most critically affected are ____, ____, and _____(land used to grow crops).
Basic facilities and services that support a community, such as public water supplies, sewer lines, power plants, roads, subways, schools, hospitals, etc.
More people are living in cities than in rural areas.
What are some symptoms of overwhelming population growth? (6)
-insufficient resources (burnable fuel, food, H2O)
Examples of overwhelming population growth?
•Women collecting wood for their stoves
•Unsafe water (use the same water for bathing, washing clothes, and drinking)
•Not enough housing (so may get slums, or tent communities), may use arable land to house people
In this century, countries may be labeled more developed or less developed. Not all countries are going through the demographic transition in the same way that the more developed countries did. What is an example?
some countries have rapid population growth but are unable to make enough educational and economic gains to reduce the birth rate and move into the 3rdStage.
International communities focus on the least developed countries -____________________ to address population and environmental problems.
give them priority to foreign aid and development programs
Ways to Reduce Birth Rates
family planning programs
•Openness to changing social traditions
•Cooperation of private and nonprofit organizations with government
One Child Policy
have to pay lots of money intaxes for more children.
One Child Policy
______ project that the world population will reach about ___ billion in _____.
all members of a species living in the same place at the same time
How is population described?
Described in size, density, or dispersion.
Example would be?
Bass in an Iowa lake
# of individuals in a species.
# of individuals per unit area or volume
Example of Density?
# of bass per cubic meter of water in the Iowa lake
relative distribution or arrangement of its individuals within a given amount of space.
How do you describe dispersion?
Can be clumped, even, or random
change in population of a given time.
+, -, or 0
Populations grow by?
maximum # of offspring each member of a population can produce
larger # of individuals is added to the population in each succeeding time period. (population grows faster and faster).
Populations increases when species can produce more offspring at a time, reproduce more often, or reproduce earlier in life.
Must have plenty of food, space, no competition, and no predators
Ex. of exponential growth
how molds grow on food
What limits population?
-Competition within a populations
maximum population an ecosystem can support
For food, territory, etc.
Competition within a populations
As population nears carrying capacity growth declines........
-Birth rate decreases because have fewer resources available for offspring.
-Death rates increase because fewer resources for survival
When population reaches carrying capacity:
-Birth rate =
-Population growth =
How Species Interact With Each Other?
relationship in which different individuals or populations attempt to use the same limited resources
-Occurs within and between species
-Compete for food, same resources (their niche -food and territory)
2 species compete but never interact with each other
Example of indirect competition
•Ex.) insect species eat certain plants in the day and the other species eats the same plant at night.
•Ex.) 2 plant species flower at the same time and compete for the same pollinators
when 2 species with similar niches are placed together in the same ecosystem, usually one species is more successful than the other.
Adaptation to competition
The better adapted species can use more of the ____.
Competition _____ between species by dividing up _____ in ____ and ____.
Example fo Adaptation to competition?
•Ex.) 2 species of barnacles: one species lives in higher tidal levels, and the other lives in the lower tidal levels
-But if one species is missing the other species will consume all of the tidal region.
animal feeding on its prey. If a predator eats a certain type of prey then we will see both populations increase and decrease together in a pattern.
organisms that live on or in another organism (host) and feed on it.
2 species are benefiting from each other.
Example of Mutualism
Ex.) bacteria in the intestines -break down food in your intestines and you give it a habitat.
1 organism benefits and the other is neither helped nor harmed (neutral)
2 organisms live in close association to one another
Symbiosis and coevolution
Over time species in close relationships may ____. -evolve adaptations that ___ the harm or ____ the benefit of the relationship
Ex.) Shark and remoras (fish) -remoras attach themselves to sharks and "catch a ride" then feed on scraps of food left over from sharks' feast.
the organisms in a few small areas are counted and projected to the entire area.
involves capturing individuals, marking them, releasing them, and then later recapturing individuals from the same population and counting the number of marked and unmarked individuals.
Capture (mark) and recapture
Population can be fairly accurately estimated from the proportion of marked -vs-unmarked animals.
Capture (mark) and recapture
random sampling of blocks within a larger grid matrix.
Samplers need to develop a set of "___" that address species that may span over two or more boxes.