1. Lecture 11 –
LIFE HISTORY STRATEGY

2. Life History Strategy
A suite of traits that improve an individual's chances of surviving and reproducing in a particular environment

3. COST/BENEFIT ANALYSIS
Energy committed to one function is not available for others.

4. COST/BENEFIT ANALYSIS
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
-less energy directed to growth
-size restriction

5. COST/BENEFIT ANALYSIS
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

6. Macarthur and Wilson (‘70’s) - Theory of Island Biogeography
R.H. Macarthur
Macarthur and Wilson (‘70’s) - Theory of Island Biogeography
r strategists K strategists
E.O. Wilson
Opportunistic
-rapidly colonizing, fast growth
Equilibrium
-slower colonizing, slow growth

7. Attributes of r and K - selected organisms
r - selected
K - selected
Consistent, predictible
Density dependent, uncertain juvenile survival
Consistent
More species, no recolonization
Long
Slow development, late reproduction, low rate of increase, larger body size
Greater % to growth and maintenance
Climate
Variable, unpredictible
Consistent, predictible
Density independent, uncertain adult survival
Density dependent, uncertain juvenile survival
Mortality
Variable, below K
Consistent
Population Size
More species, no recolonization
Community Characteristics
Few species, recolonization
Lifespan
Short
Long
Rapid development, early reproduction, high rate of increase, small body size
Slow development, late reproduction, low rate of increase, larger body size
Individual Attributes
Greater % to growth and maintenance
Allocation of Energy
Greater % to reproduction

8. 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

9. 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

10. Look at our original energy allocation graphs
More r - like
More K - like

11. r - K continuum r-strategist K-strategist Frequent disturbance
Less frequent disturbance

12. Aclonal Life History
recruitment
Sexual reproduction
Death

13. Clonal Life History recruitment Death Sexual reproduction Fission

14. 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