Life Histories Flashcards
Define life histories
aspects of the natural history of an organism directly related to survival and reproduction
examples of life histories traits
maturity (when can reproduce)
longevity (lifespan)
fecundity (how many offspring reproduce)
parity (how many reproductive events)
why do tradeoffs occur
because their is a finite about of energy and resources and must decide where to allocate resources
what are risks associated with tradeoffs (specifically reproduction and growth)
can die before reproduce
can produce lower quality or less if reproduce before growing
examples of tradeoffs
between fecundity and survival
between present and future reproductive success
what 5 traits does the perfect organism have
- born mature
- continually reproducing
- high number of offspring
- high quality offspring
- lives forever
reproductive strategies are optimized by determining what “questions”
when, how many, how many times, how big, sex ratio
What is lack’s hypothesis
selection favours clutch sizes that produces the highest number of surviving offspring
why is clutch size often lower than expected in lack’s hypothesis
tradeoffs between:
1. parental fitness/ future reproductive success
2. fewer individuals may be of higher quality
3. fewer individuals may have increased survival
Explain the tradeoff of “how big”
tradeoff between size and number of offspring
altricial (offspring that require parental care)
precocial (offspring that do not require parental care when born)
Explain the tradeoff of “how often”
if semelparous (reproduce once) OR
if iteroparous (reproduce multiple times)
how can individuals adjust the sex ration
food availability, sexual size dimorphism, fitness/attractiveness of fathers, fitness/ranking of mothers
