• increase in numbers
without any limits to
their growth
• J-shaped curve
• ex. bacteria
DEMOGRAPHY
statistical study of population changes
EXPONENTIAL
GROWTH
LO N G TER M C O N SEQ U EN C ES
• degradation of natural environment
• inequality in resource access
• climate change
DYANNE DANE D. CAPILI
SCIENCE11 (CK)
LIFE TABLES
- mortality rate
- life expectancy at
each interval
- life history of organism
GROWTH
1. competition for food
2. ability to find a mate
- compare the life
histories of different
populations
POPULATION DENSITY
FORMULA
number of individuals per unit area
TYPES
No. of individuals dying x 1,000
No. of individuals surviving
FORMULA
• EFFECTS ON INTERACTIONS
WITHIN A POPULATION
SURVIVORSHIP
CURVES
Type I (humans)
Type II (birds)
Type III ( trees)
DEMOGRAPHICS
Population growth = r N
LOGISTIC
GROWTH
r = birth rate – death rate
POPULATION SIZE
VALUE CAN BE:
( + ) = increasing
( - ) = decreasing
( 0 ) = unchanging
• limits to reproductive
growth
• S- shaped curve
• ex. yeast
total number of individuals
P O P U L AT I O N
DY N A M I C S
• BIRTH AND IMMIGRATION
increases population size
• DEATH AND EMIGRATION
lead to the decline in population size
FORMULA
[
rN
K–N
K
]
SPECIES
DISTRIBUTION
K = carrying capacity
RANDOM
R E G U L AT I O N
• density-dependent factors (biotic)
• density-independent factors (abiotic)
CLUMPED
ESTIMATING POPULATION SIZE
• COUNTING
UNIFORM
most accurate way, but not feasible
for large areas.
• QUADRAT
immobile organisms or for very small
and slow-moving organisms
example:
- dandelions with
wind-dispersed seeds
example:
- oak trees
- schools of fish
example:
- sage plants
- penguins
• MARK AND RECAPTURE
smaller mobile organisms, such as
mammals