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2013-07-03 09:09:57

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    • R0: net reproductive rate
    • x: age interval
    • lx: percent population surviving until age x (survival rate)
    • mx: average # offspring produced by each individual in each age category (birth rate)
    • Create a table of this data and sum R0 to determine the final #offspring/individual
  1. Life history characteristics
    • Life stages (larva and adult? male/female?)
    • Age at maturity
    • Age at 1st reproductive event
    • # of reproductive events
    • # and size of offspring
    • Post-reproductive lifespan
  2. Darter fish study
    • Fish that produced more eggs produced smaller eggs
    • Populations with many small eggs had fewer allelic differences than pops from few large eggs
    • Larvae from lg eggs: hatch earlier, feed earlier, do not drift as far, & do not disperse great distances
  3. What are the 4 basic plant forms?
    • Graminoids: Grass and grass-like plants.
    • Forbs: Herbaceous, non-graminoids.
    • Woody Plants: Woody thickening of tissues.
    • Climbers: Climbing plants and vines
  4. What are the 6 seed dispersal methods?
    • Unassisted: No specialized structures.
    • Adhesion: Hooks, spines, or barbs.
    • Wind: wings, hair, (resistance structures).
    • Ant: Oil surface coating (elaisome).
    • Vertebrate: Fleshy coating (aril).
    • Scatter-hoarded: Gathered, stored in caches
  5. Explain benefits/reasoning behind dispersal methods in plants
    • Dispersal method influences seed size
    • Plants producing a large amount of small seeds have an advantage in disturbed areas (weeds)
    • Plants producing larger seeds produce less #
    • Larger seeds produced larger/taller seedlings (more investment)
  6. How do vertebrate energy budgets differ before and after sexual maturity?
    • Before: maintenance / growth
    • After: maintenance / growth / reproduction
    • Individuals delaying reproduction grow faster and to a larger size and have increased rates of reproduction when mature
  7. Describe the influence of mortality on pumpkinseed sunfish life histories
    If adult survival is low relative to juvenile, natural selection results in allocating more resources to reproduction
  8. Describe R and K selection
    • r selection: (per capita rate of increase)
    • Characteristic high population growth rate.
    • Unpredictable Environments
    • highest intrinsic rate of increase
    • Numerous individuals rapidly produce
    • –K selection: (carrying capacity)
    • Characteristic efficient resource use.
    • Predictable environments
    • Most competitive ability
    • Fewer, larger, individuals slowly reproduce
  9. Describe Grime's study with stress/disturbance
    • Disturbance: destroys biomass
    • Stress: external constraints limit productivity
    • Four extremes: low low, low high, high low, and high high
    • Competitive species dominate under low/low
    • stress-tolerant species dominate under low disturbance high stress
    • Annual grasses common under high disturbance low stress
  10. Opportunistic, Equilibrium, and Periodic Life Histories
    • lx: juvenile survivorship
    • mx: fecundity
    • αx: age of reproductive maturity
    • Opportunistic: low lx & low mx & early αx
    • Equilibrium:  high lx & low mx & late αx
    • Periodic:  low lx & high mx & late αx
    • Graphed on a 3 point graph to compare species
  11. λ=Nt+1/Nt
    • λ: Geometric rate of increases (non overlapping generations)
    • Nt+1: size at time in future
    • Nt: size at time
  12. T=(Σxlxmx/R0)
    • T: average generation time
    • x: highest age in range
    • lx: percent population surviving until age x (survival rate)
    • mx: average # offspring produced by each individual in each age category (birth rate)
    • Ro: Σlxmx
  13. r=ln(Ro/T)
    • r: per capita rate of increase (is population increasing or decreasing?)
    • R0: net reproductive rate
    • T: average generation time
  14. Nt=N0λt
    • Nt: # individuals at time t
    • N0: initial # individuals
    • λ: geometric (nonoverlapping) rate of increase
    • t: # time intervals/generations
  15. dN/dT=rmaxN
    • dN/dT: change in population over time
    • rmax: population growth rate (maximum possible)
    • N: population size
    • For use in overlapping generations in an unlimited environment
  16. Nt=N0ermaxt
    • Nt: # individuals at time t
    • No: initial # individuals
    • e: base of natural log
    • rmax: per capita rate of increase
    • t: number of time intervals
    • For use with overlapping generations
  17. dN/dT=rmaxN(1-N/K)
    • For use with determining the effect of carrying capacity on overlapping generations population (logistic growth)
    • rmax: maximum per capita increase
    • N: # individuals
    • K: carrying capacity
    • N/K: environmental resistance
    • too low will be not enough # individual to cause change
    • too high will result in too many resources used
  18. Describe various modes of resource competition
    • Exploitative: differential ability to acquire resources
    • Interference: Direct aggressive interaction between individuals
    • Intraspecific: within one species
    • Interspecific: between different species
  19. Define niche
    • All of the possible environmental factors that influence growth, survival, and reproduction of a species.
    • Hutchinson defines: n-dimensional hypervolume
    • n- all factors a species needs to reproduce
    • hypervolume-physical factors (not interactions)
  20. Fundamental vs realized niche
    • Fundamental: Hypervolume. Physical factors ONLY
    • Theoretical max
    • Realized: part "occupied", includes competition
    • Real niche in nature
  21. Describe the paramecium experiment
    • Competitive exclusion: two species with identical niches cannot coexist indefinitely
    • Better competitor eventually excludes other
    • K determined by intraspecific competition when grown alone
    • K determined by interspecific competition when growth together
  22. Describe Character displacement
    • Degree of competition depends on niche overlap
    • Character displacement causes directional selection for reduce nicheoverlap
    • The beak depth in the finch example was more polarized when the two were on the same island!