Lecture 10: life history Flashcards
(13 cards)
What is a life history?
It refers to how organisms allocate time and energy to activities like growth, reproduction, and survival over their lifetime.
What is a trade-off in life history?
It’s when allocating more energy to one function (e.g., reproduction) reduces the energy available for another (e.g., survival).
What is lifetime reproductive success (LRS)?
A: Total number of offspring produced over an individual’s life (not accounting for their survival to reproductive agg- gont confuse with fitness)
What is a life history strategy?
A set of decisions and traits affecting how an organism allocates resources to reproduction, growth, and survival.
Name three qs of life history strategy
How often to breed?
When to begin reproducing?
How many offspring per event?
What influences life history strategies?
Abiotic and biotic environmental conditions shaped by natural selection.
semelparity? vs iteroparity?
A: Reproduce once, then die (e.g., salmon, agave).
Reproduce multiple times during life.
When is semelparity favored?
A: When adult survival is low or when conditions for offspring survival are highly variable.
What is the trade-off with more offspring per event? and Why might parents produce fewer offspring than they can?
A: More offspring usually means less care and lower survival per individual
A: To preserve energy and increase long-term reproductive success.
When do organisms delay reproduction?
: When do organisms reproduce early?
A: If they have long lifespans and high survival rates.
A: If they have short lifespans or low annual survival rates.
What is senescence?
A: Gradual increase in mortality and decline in fecundity with age.
What characterizes r-selected species?
Small size, early maturity, many offspring, low parental care, semelparous.
opp is k selected
What is favored when resources are unlimited?
What is favored when resources are limited?
A: r-selected strategies: rapid reproduction and population growth.
K-selected strategies: competitive survival traits. (rmbr, limited= trade off more allocate energy on growth)
