Chapter 8 Flashcards
what do life history traits represent
the schedule of an organism’s life
Life history
the schedule of an organism’s growth, development, reproduction, and survival; represents an allocation of limited time and resources to achieve maximum reproductive success
the schedule of an organism’s growth, development, reproduction, and survival; represents an allocation of limited time and resources to achieve maximum reproductive success
Life history
Fecundity
the number of offspring produced by an organism per reproductive episode
the number of offspring produced by an organism per reproductive episode
Fecundity
Parity
the number of reproductive episodes an organism experiences
the number of reproductive episodes an organism experiences
Parity
Parental investment
the time and energy given to an offspring by its parents
the time and energy given to an offspring by its parents
Parental investment
Longevity (life expectancy)
the life span of an organism.
the life span of an organism.
Longevity (life expectancy)
what do life history traits often vary consistently with
life form, habitat, or environmental conditions
What is variation in one life history trait often correlated with
variation in other life history traits
“slow” life history
- long time to sexual maturity
- long life spans
- low numbers of offspring
- high parental investment
Examples: elephants, oak trees
“fast” life history
- short time to sexual maturity
- short life spans
- high numbers of offspring
- little parental investment
Examples: fruit flies, weeds
short life
r-selected
rapid growth
r-selected
early maturity
r-selected
many small offspring
r-selected
little parental care or protection
r-selected
little investment in individual offspring
r-selected
adapted to unstable environment
r-selected
pioneers, colonizers
r-selected
niche generalists
r-selected
prey
r-selected
regulated mainly by extrinsic factors
r-selected
low trophic level
r-selected
long life
K-selected
slower growth
K-selected
late maturity
K-selected
few, large offspring
K-selected
high parental care or protection
K-selected
high investment in individual offspring
K-selected
adapted to stable environment
K-selected
later stages of succession
K-selected
niche specialists
K-selected
predators
K-selected
regulated mainly by intrinsic factors
K-selected