Studied by 15 people
definitions, concepts, and more on CHPT 8 for APES :)
Population
all individuals living on a planet at a given time.
Total Fertility Rate
The average number of children born to women during their lifetime.
Replacement Level Fertility
The average number of children couples must have to replace themselves.(this equals 2.1)
Percent Annual Growth (PAG)
the percent change in the population after 1 year
Birth Rate
The number of live births per 1,000 people (male + female).
Death Rate
The number of deaths per 1,000 people (male + female).
Immigration
the act of entering a region or country in which a person did not previously live.
Emigration
the act of leaving a region or country in which a person has lived in.
Urbanization
an increase in the % and the number of people living in urban settlements.
Infant Mortality Rate
the number of individuals 1 year of age or younger who die per 1000 people.
Doubling time
the time it takes for a population to double in size (70/R) (R = percent annual growth rate)
Demographic Transition Graph
Pre-Industrial: BR and DR are high
Transitional: DR declines due to an increased good population and improved medical care. BR remains high
Industrial: BR declined due to increased opportunities for women and access to BC. DR continues to decline.
Post-Industrial: BR and DR are low because of low medical care and food availability
IPAT Model
The model identifies the population size, affluence, and technology factors of ecological impact. You can find a population's general environmental impact.
Thomas Malthus ideas
populations grow EXPONENTIALLY. food resources grow LINEARLY. leads to starvation. "Population will outgrow foody supply"
How the average ecological footprint of a country and the total size of the population affects the environmental condition of a region?
Affects: because of the IPATT model (population x affluence x technology) increases, the impacts increases. The impact (footprint) is how much land and water is required to sustain a population. So low footprint and low population means low envir impact. High foot print and high population means high envir impact.
Describe the rate of growth for humans over the last 100,000 years. When have most people been added to the world's population
The rate of growth is exponential. This is due to the acceleration with agricultural revolution and industri
Density Dependent
Limiting factors that depend on population size. Does not affect small, scattered populations.
ex: disease, competition
Density Indepedent
factors that affect the population regardless of their size
ex: unusual weather, season cycles, human activities
generalist species
broad niche, live in many different areas, eat a variety of food, tolerate wide ranges of environmental conditions
ex: opossum
specialist species
narrow niche may only live in one type of habitat, few types of foods they can eat, can tolerate a narrow range of environmental conditions
ex: koala
k-selected species
k = carrying capacity
organisms live in stable environments usually in large sizes mature slowly but live loner a lot of energy is invested in offspring usually are predators (elephants, apes, bears, etc) long lifespan (type 1 curve) graph: S shaped curve
r-selected species
r = biotic potential
organisms live in changeable environments usually live in small in size and mature quickly usually are prey organisms produce high # of offspring little to no parental care short life span (type 3 curve) graph: J shaped curve
How preindustrial BR and DR compare to BR and DR of industrialized countries
BR and DR ijn the pre-industrial stage are high and are balanced. In the industrialized stage, BR remains high but starts to slow down but DR is decreasing rapidly due to the transitional stage
Survivorship Curve
survivorship: the amount of a population that remains alive at a certain age
type 1 curve - shows individuals that have a high probability of surviving through early and middle life but have a rapid decline in the number of individuals surviving into late life (ex: elephants)
type 2 curve - in between r and k strategists (ex: squirrel)
type 3: species where few individuals will live to adulthood and die as they get older (ex: trees)
y axis: survivorship x axis: age
Why can't populations sustain infinite rizz i mean growth
when the # of individuals gets large enough it reaches carrying capacoty so resources get depleted, which slows the GR
ecological footprint
the number of natural resources a population requires to survive
GR equation (population growth)
GR = (BR + IR) - (DR+ ER)
BR: birth rate DR: death rate IR: immigration rate ER: emigration rate
positive feedback loop
Causes a system to change further in the same direction. Example: melting of Arctic sea ice
negative feedback loop
A feedback loop that causes a system to change in the opposite direction from which it is moving. Example: reproduction --> overgrazing --> less reproduction
reasons for GR
technological innovations, improved sanitation, better medical care, increased agriculture
age structure
rapid growth: severe curve, lots of young people, high reproductive rate (ex: Nigeria, Kenya, Saudi Arabia)
slow growth: stable growth, very balanced age groups (ex: United States, United Kingdom)
zero growth: way more older people compared to younger people, lower reproductive rate (ex: Denmark, Italy, Austria)
