Life History Tradeoffs Flashcards
Principle of Allocation
Amt of energy available limited to each organism
What is life history
Description of organisms characteristics from birth till death
5 key life history traits
body size- length weight etc
fecundity- num offspring per episode
parity- num episodes for reproduction
-maturity- at what time can mfs reproduce
aging/ senescence- life span
Organisms exist to
maximize reproductive success
semelparous vs iteroperous
semelparous mean one reproduction event per life
iteroperous means multiple throughout lifetime
Monocarpic plant
flowers and sets seeds once
polycarpic plantA
flowers and sets seeds multiple times
Annual Plant
completes life cycle in one growing season
Perrenial plant
completes life cycle in multiple growing seasons
Allometry
study of scaling between body size and various biological traits and function
What is significant about body size
influences relationship between temperature, energy, water, nutrient aquisition
Offspring size vs. offspring __
number
Seed size vs. seed ____________
explain
-dispersal
-larger the seed mass, the larger the dispersal
-because big mfs eat seeds and move them places, while wind takes them low distance
-also coorelated with plant height
dispersal
permanent movement
migration
non permanent movement- seasonally
seed dispersal
spread of seeds from mother plant
what factors affect seed dispersal
plant height, seed size
gene flow
transfer of genetic information across populations
how does having more, smaller eggs affect gene flow?
bigger eggs have low gene flow, less eggs have more gene flow
-they drift further away
-low genetic isolation
in grasses and forbs, larger seedling are associated with
higher requitment rates
Reproductive effort
allocation of energy towards reproduction, formation of eggs and offspring care
what happens when organism invests early into reproduction
cannot allocate more to growth and survival
Organisms that opt for survival rate
reproduce at later stage
reproduce at later date
as mean adult survival rate increases
so does mean age at maturity
Fish with higher mortality rates
reach reproductive maturity at earlier age and vice versa
Variation of life history within species example
(hooknose and jack)
Hooknose and jacks
hooknoses fight for female, mature at later age
jacks sneak fuck female–> mature earlier
Characteristics selected for by r species
pop growth
competetiveness
development
reproduction
body size
reproduction
offspring
high potential pop growth rate
not favored
fast
early
small
semelparitous
small and fast
Characteristics selected for by k species
pop growth
competetiveness
development
reproduction
body size
reproduction
offspring
low
favored
slow
late
large
iteroparitous
large and slow
Grimes Triangle
3 corners of classifying life history for plants–> competitive
ruderal
stress tolerant
Grimes Triangle: Competitive
-Low disturbance, high productivity environments
-plants usually grow fast
Grimes Triangle: Ruderal
-High disturbance, low stress environments
-grow rapidly
-large amts of tiny seeds
-often annual plants
-invest little in growth and maintenence
Grimes Triangle: Stress Tolerant
-high stress, low competitive environments
-glow slowly
- invest in physiological stress tolerance OVER growth
is it common for plants to fall in the corners?
No, most plants fall within the triangle, showing characteristics of each
E P O scheme
-opportunistic life history–>
-periodic life history–>
-equilibrium life history–>
opportunistic life history
low survival, EARLY MATURITY, high fecundity
periodic life history
low survival, late maturity, HIGH FECUNDITY
equilibrium life history
HIGH SURVIVAL, qlate maturity, low fecundity
