Trade-Offs and Life History Flashcards
Principle of Allocation
- the amount of energy and time to each organism is limited
- when energy and time is allocated towards one function it reduces those resources for others
What is Life History
is a description of the major characteristics of an organism from its birth to its death
Key Life History Traits
body size, fecundity, parity, maturity, aging/senesence
Define Fecundity
of offspring per episode
Define Parity
of episodes for reproduction
- animals can be semelparous (one event) or iteroparous (multiple events)
- plants can be monocarpic (flowers and set seeds only 1X) or polycarpic (flowers and set seeds multiple times)
Define Maturity
age at 1st reproduction
What is allometry
the study of scaling between body size and various biological traits and functions (shape, anatomy, physiology, behavior, etc.)
Why is body size studied in allometry?
it influences relationships with temperature, energy, water and nutrient acquisition
What do Life Histories represent?
various ways of allocating limited resources among functions given the trade-offs
Trade-off: Offspring size vs. Offspring Number
those that produce larger offspring are constrained to produce fewer, whereas those that produce smaller offspring may produce larger numbers
What is Seed Dispersal
the spread of seeds from the mother plant across space
Trade-off: Seed size vs. Seed Dispersal Distance
- the larger the seed mass , the wider plants can disperse
- is a weaker trade- off
Trade off: Seed size vs. Seed survival
in grasses and forbs, larger seeds produced larger seedlings and ultimately was associated with increased recruitment
Define Reproductive effort
the allocation of energy, time and other resources to reproduction, including the formation of eggs and offspring care
Why is reproduction costly?
- organisms that invest early in reproduction cannot allocate more energy to growth and survival
- organisms that opt for a higher survival rate reproduce at a later life stage
