Life history

Definition

Life history describes the series of events and strategies an organism undergoes from birth to death, including growth, reproduction, and survival. It is shaped by evolutionary pressures to maximize fitness in a given environment.

5 Must Know Facts For Your Next Test

1. Life history traits include age at first reproduction, number of offspring, and lifespan.
2. Organisms with r-selected life histories produce many offspring with low survival rates.
3. Organisms with K-selected life histories produce fewer offspring with higher survival rates.
4. Trade-offs in life history traits occur because resources are limited; investing in one trait often reduces investment in another.
5. Semelparity refers to organisms that reproduce once before dying, while iteroparity refers to those that reproduce multiple times throughout their lives.

Review Questions

• What are the key traits involved in an organism's life history?
• How do r-selected and K-selected species differ in terms of reproductive strategies?
• What is the difference between semelparity and iteroparity?

Related terms

r-selection:

A reproductive strategy characterized by high reproductive rates and low parental investment per offspring.

K-selection:

A reproductive strategy characterized by low reproductive rates but high parental investment per offspring.

Trade-off: The concept that organisms face limitations on resource allocation, leading them to balance different life history traits.