APES Unit 3 Flashcards
Species specialist characteristics
-small range of tolerance
-narrow ecological niche
-more prone to extinction
-specific food/habitat requirements
-less ability to adapt
Species Generalists characteristics
-larger range of tolerance
-broader niche
-less prone to extiction
-more likely to be invasive species
-broad food/habitat preference
ecological niche
role a species plays within the ecosystem (it’s way of life)
biotic potential
maximum reproductive rate under ideal conditions
k-selected species characteristics
○ few offspring, heavy parental care to protect them.
○ EX: most mammals, birds
○ longer life span - long time to sexual maturity = LOW biotic potential
○ more vulnerable to disruptions and invasive species
○ if parent dies = likely death of offspring
○ more likely to go extinct
○ often specialist species
r-selected species
○ many offspring, little to no care
○ EX: insects, fish, plants
○ shorter life span - quick sexual maturity = high biotic potential
○ more likely to be the invasive species
○ better suited for rapidly changing environmental conditions
○ parent dies doens’t affect offspring
○ low chance of extiction
○ often generalist species
survivorship curves
line on a graph that shows survival rate of a cohort from birth to death.
cohort
group of the same-aged individuals
type 1survivorship curves
life stages
○ mostly k-selected species
○ high survivor-ship early in life due to parental care
○ high survivor-ship mid-life due to large size
○ rapid decrease in survivor-ship in late life as old age
EX most mammals
type II survivor-ship curves
○ in between k and r selected species
○ steadily decreasing survivor-ship throughout life
○ they tend to be the prey
EX birds, mice
type III survivor-ship curve
○ mostly r-selected species
○ high mortality early in life due to little parental care
○ few make it to mid-life; slow down decline in survivor-ship midlife
○ even fewer make it to adult hood
EX insect, fish, plants
Survivor-ship and k- and r- selected species are like a spectrum
r on the very left with Oyster having 500 million offspring anually
k on the very right with chimps having 1 offspring every 5 yrs.
Carrying Capacity
highest population size the environment con support based on limiting resources
Food, Water, Habitat
Overshoot
EX
when population exceeds carrying capacity
EX deer bread in fall and give birth all at the same time leading to a pop. spike in spring = overshoot
consequences of overshoot
resource depletion EX overgrazing deer
Die-off
EX
sharp decrease in pop. size when resource depletion leads to individuals dying.
EX many deer starve with too many new fawns feeding in the spring.
how can overshoot and its consequences affect a population?
sometimes populations grow exponentially and they way way overshoot. if resource depletion is too drastic, the population can die off completely.
Predator prey graph
○ Prey pop. incr. due to lowering predator pop.
○ predator pop incr. due to incr. prey pop.
○ prey pop. decr. due to more predators eating them
population characteristics
size (N)
density
distribution
sex ratio
population characteristics Size (N)
total number of individuals
population characteristics Density
number of individuals/area
- high density = more competition
- more likely for disease to spread
population characteristics Distribution
how individuals are spaced
a) random EX trees, plants
b) uniform EX territorial animals
c) clumped EX herd/group animals
population characteristics Sex ration
males : females 50:50
die-off and bottleneck effects can lead to skewed ratio (not enough females) limiting pop. growth
what limits population growth?
the availability of resources (food, space) limits pop. growth. Resources are limited and finite over time for all populations
exponential growth
j-curve steep going up without flattening
pop size y axis
time x axis
-if resources are abundant pop. follows exponential growth
- shows high biotic potential
logistic growth
starts going steep but then flattens out at carrying capacity
S curve
- if resources are more limited pop. follows logistic growth model
what 2 things happen when resources are scarce?
a) increased mortality- more organisms starve/die
b) decreased fecundity - organisms reproduce less or not at all
fecundity
reproductive ability
Density dependent factors that regulate population growth
influence pop. growth depending on pop. size
- food, competition for resources
- disease
- larger populations will be more affected
density independent factors that regulate population growth
influence pop. growth independent of size
- natural disasters (flood, hurricane, tornado, pollution)
- doesn’t matter how big or small pop. size is
changing factors that determine calculating population size
birth, death
emigration, immigration
formula or easiest way to solve total population
start with original number
add births minus deaths
add immigration minus emigration
then add this number to original
EX 52 elk 19 births 6 deaths
9 emigrate 5 immigrate
18 new elk 52+18=70
percent change formula
(NOO)
new-old/old* 100
EX 52 elk original
70 elk new
70-52/52*100 = 34.6%
Thomas Malthus and his theory
earth has a carrying capacity for humans based on limited food production. Human growth is exponential while food production is not.
why was Thomas Malthus wrong? what did he not take into account?
humans alter earth’s carrying capacity with technological advancements. EX synthetic fertilizer
calculating growth rate
CBR-CDR/10 as %
doubling time (rule of 70)
doubling time = 70/growth rate yrs.
factors that increases population growth rate
- High TFR
- High IMR drives up TFR (replacement children)
- high immigration level
- increased access to clean water & healthcare (decreasing DR)
- government incentives
factors that decrease pop. growth rate
-high death rate
- high IMR
- increased development
- increased education and opportunities for women
- delayed age of first child
- postponed of marriage age
- government incentive EX china’s one-child policy
standard of living
quality of life
Gross Domestic Product
Life Expectancy
standard of living GDP
gross domestic product is the total value of goods and services provided.
standard of living life expectancy
avg. age a person will live
incr. with access to clean water, healthcare
High GDP and life expectancy are indicators of what?
indicate development and low population growth
age cohort
group of similarly aged individuals
Age structure diagrams expanding rapidly
wide bottom of pyramid little at the top
Age structure diagrams expaning rapidly
wider bottom than top but growing more slowly
Age structure diagrams stable
not growing or shrinking population. Steady, stable
Age structure diagrams declining
less babies being born than there are older people
ages 0-14
ages 15-44
ages 44+
pre reproductive
reproductive
post reproductive
TFR (total fertility rate)
is the avg. number of children a women will have.
higher TFR → higher birthrate → high pop. growth (generally)
IMR (number of children)
number of children dying under the age of 1 / 1000
- high in less developed countries due to less healthcare, clean water, sanitation
- higher IMR → TFR → (replacement children)
replacement level fertility
fertility rate that keeps pop. stable (to replace parents)
2.1 in most developed countries
factors that affect TFR developement (affluence)
developement (affluence)
- more developed, wealthier nations have lower TFR
– education for women
– more economic opportunities for women
– later age of first pregnancy
– higher access to family planing, contraceptives
– less need to children to help work
Factors that affect TFR government incentives
Government incentives
-to either lower or increases pop. growth
–forced sterilization
–china’s 1 child policy (now 3)
– tax incentives
– microcredits or loans for women without children to start buisnesess.
industrialization
process of economic and social transition from farming to industrial
pre-industrialized
not yet industrialized
industrialization/ develping
part way through transition
industrialized
completed transition
DTM stage 1 characteristics
- pre industrialized
– no countries in this stage
– high IMR & death rate due to lack of clean water, sanitation, healthcare
– high TFR due to lack of education, family planing
– need for child agricultural labor
– little to no growth, high CBR and CDR cancel each other out
DTM stage 2 characterisistcs
- industrializing/ developing
– IMR and CDR are declining
– high TFR due to lack of education, need for child agricultural labor, access to family planing, generational lag
– rapid growth, fastest pop. growth
generational lag
it takes time for a society/ culture to change and adapt
DTM stage 3
- developed/ industrialized
– modernized economy
– country becoming wealthier
– low TFR due to education for women, access to family planning, delayed age of marriage and first child
– slowing growth rate as CBR drops
DTM stage 2 economical/ societal indicators
– Low GDP
– short life expectancy
– high TFR
– low literacy rates (people, especially girls, not in school)
DTM stage 3 economic/ societal indicators
–getting wealthier, high GDP
– long life expectancy
– low infant mortality
– TFR near replacement level (2.1)
– high literacy rate and school life expectancy for girls
DTM stage 4 characterisistcs
-post industrialized/ highly developed
– highly developed
– increase in education
– CBR drops lower than CDC = steady or even declining pop
DTM stage 4 economic/ societal indicators
– high GDP, very wealthy
– longest life expectancy
– TFR below replacement level
– highest contraceptive use rates
