Transcript Life History Strategy

Lecture 11 –
LIFE HISTORY
STRATEGY
Life History Strategy
A suite of traits that improve an
individual's chances of surviving and
reproducing in a particular environment
COST/BENEFIT ANALYSIS
1.
Energy committed to one function is not available for
others.
Growth
Respiration
Reproduction
Predator Defense
Growth
Respiration
Reproduction
Predator Defense
COST/BENEFIT ANALYSIS
1.
Energy committed to one function is not available for
others.
2.
Every evolutionary ‘choice’ has costs and benefits
Settles on wave exposed shore
Costs
Benefits
-energy in holding on
-less exposure to predators
-restricted movement for food
gathering
-more food delivery
-size restriction
-less energy directed to
growth
COST/BENEFIT ANALYSIS
1.
Energy commited to one function is not available for others.
2.
Every evolutionary ‘choice’ has costs and benefits
3.
Every organism represents a compromise of a number of
evolutionary ‘choices’
Periclimenes yucatanicus
Colour - bright & obvious to predators
- disruptive
Hides in anemone – restricted foraging
but has protection
Exoskeleton – restricts movement but
offers protection
Macarthur and Wilson (‘70’s) - Theory of Island Biogeography
r strategists
Opportunistic
-rapidly colonizing, fast
growth
K strategists
R.H. Macarthur
E.O. Wilson
Equilibrium
-slower colonizing, slow
growth
Attributes of r and K - selected organisms
r - selected
Climate
Mortality
Population Size
K - selected
Variable, unpredictible
Consistent, predictible
Density independent,
uncertain adult survival
Density dependent,
uncertain juvenile survival
Variable, below K
Consistent
More species, no
recolonization
Community Characteristics
Few species, recolonization
Lifespan
Short
Individual Attributes
Rapid development, early
reproduction, high rate of
increase, small body size
Slow development, late
reproduction, low rate of
increase, larger body size
Allocation of Energy
Greater % to reproduction
Greater % to growth and
maintenance
Long
Attributes of r and K - selected organisms
r - selected
K - selected
Climate
Variable, unpredictible
Consistent, predictible
Mortality
Density independent,
uncertain adult survival
Density dependent,
uncertain juvenile survival
Population Size
Variable, below K
Consistent
Community Characteristics
Few species,
recolonization
More species, no
recolonization
Lifespan
Short
Long
Individual Attributes
Rapid development, early
reproduction, high rate of
increase, small body size
Slow development, late
reproduction, low rate of
increase, larger body size
Allocation of Energy
Greater % to
reproduction
Greater % to growth and
maintenance
Productivity
Attributes of r and K - selected organisms
r - selected
K - selected
Climate
Variable, unpredictible
Consistent, predictible
Mortality
Density independent,
uncertain adult survival
Density dependent,
uncertain juvenile
survival
Population Size
Variable, below K
Consistent
Community Characteristics
Few species,
recolonization
More species, no
recolonization
Lifespan
Short
Long
Individual Attributes
Rapid development, early
reproduction, high rate of
increase, small body size
Slow development, late
reproduction, low rate of
increase, larger body size
Allocation of Energy
Greater % to
reproduction
Greater % to growth and
maintenance
Productivity
Efficiency
Look at our original energy allocation graphs
Growth
Growth
Respiration
Respiration
Reproduction
Reproduction
Predator Defense
More r - like
Predator Defense
More K - like
r - K continuum
r-strategist
Frequent disturbance
K-strategist
Less frequent disturbance
Aclonal Life History
recruitment
Sexual reproduction
Death
Clonal Life History
Sexual reproduction
recruitment
Fission
Fission
Fission
Death
Life history pattern -- a genetically inherited pattern of
resource allocation to that optimizes the passing of genes
to the next generation
EGG AND SPERM PRODUCTION
FERTILIZATION PATTERNS
TYPES OF DEVELOPMENT
LARVAL DISPERSAL STRATEGIES
SETTLEMENT PATTERNS