Chapter 7 Outline
Case Study: Nemo Grows Up
Life History Diversity
CONCEPT 7.1 Life history patterns vary within and among species.
- Individuals within species differ in their life histories
- Mode of reproduction is a basic life history trait
- Life cycles are often complex
Life History Continua
CONCEPT 7.2 Reproductive patterns can be categorized along several continua.
- Some organisms reproduce only once while others reproduce multiple times
- Live fast and die young or slow and steady wins the race?
- Plant life histories can be classified based on environmental characteristics
- Life histories can be classified independent of size and time
Trade-Offs
CONCEPT 7.3 There are trade-offs between life history traits.
- There is a trade-off between size and number of offspring
- There is a trade-off between current and future reproduction
Life Cycle Evolution
CONCEPT 7.4 Organisms face different selection pressures at different life cycle stages.
- Small size has benefits and drawbacks
- Complex life cycles may result from stage-specific selection pressures
Case Study Revisited: Nemo Grows Up
Connections in Nature: Territoriality, Competition, and Life History
