Hierarchy that allows individuals to know their place
Individuals at the top have access to lots of resources
While those at the bottom have a chance to move up
Usually established at the beginning of the
organisms lives through fights but if a
newcomer joins, opportunity to move up
Competition
Mates
Gametes
Sperm
Egg
Energy cost per gamete
Low
High
Amount made
Many
Few
Reproductive interest
Fertilise as many eggs as possible
Ensure the sperm that fertilises the egg is of the highest quality
Territory
Area occupied by an animal
and defended against others
Territorial defense
1. Keep out signal
E.g. scent of urine
2. Threat Display
E.g. making themselves bigger -
cat puffing out their fur
3. Fighting
Adaptive Advantage
Benefits within territory e.g food,
shelter, breeding/mating area
Costs
Energy and time spent in it's defense
Between organisms of the SAME species
Intraspecific Co-operation
Reproductive Strategies
K - selection
Characteristics
Large size of organism
Energy used to make each individual is high
Few offspring are produced
Late maturity, often after a
prolonged period of parental care
Long life expectancy
Individuals can reproduce more
than once in their lifetime
Type I or Type II survivorship
pattern: individuals live to the
near maximum of their lifespan
Attempt to ensure the survival
of their offspring by investing
time in them, instead of lots
Stable environment, density
dependant interactions
Adaptive Advantages
r - selection
Characteristics
Small size of organism
Energy used to make individuals is low
Many offspring are produced
Early maturity
Short life expectancy
Each individual only reproduces once
Type III survival pattern:
Most individuals die within
a short amount of time but
a few live much longer
Creates an abundance of offspring with
the hopes that a few will make it
Adaptive Advantage
Unstable environment, density independent
r ____._________._________.______.________.__________._________._________._______.____ K
bacteria mollusks insects fish amphibians reptiles mammals apes humans
Courtship
Parental Care
All about passing on alleles into the gene pool
Group membership
Pros
Safety
Specific roles within groups
Dilution effect
One predator and 100 people in a population, there is a 1 in
100 chance of being preyed on, rather than one predator
and one individual, there is a 1/1 chance of preyed on
Confusion effect
If a predator approaches a group, they gap it in lots of different
directions therefore resulting in the predator becoming confused
Mating
Mates availability
Extra protection for young
Learning opportunities for young
Hunting ease
Saving energy
Decreased exposure to elements
Aerodynamics
Cons
Intraspecific competition
More visible for predation
Spread of disease
Generally intraspecific,
organisms of the same species