BIOEE 1610 1st Edition Lecture 8Outline of previous lectureI. Hierarchical organization in ecologyII. PopulationsA) GeneralB) Populations and spaceIII. Life tablesOutline of current lectureI. Life historyII. Reproduction in life historiesIII. Life tablesIV. Population growthCurrent lectureI. Life history*The pattern of an organism’s time/energy investment into growth, survival, reproduction*Strategies:-every female has limited resources-natural selection works to optimize how these resources are spent*Trade-offs-reproduce once or multiple time-reproduce many small, weak offspring or few large, strong offspring-reproduce early (hence many times) or late (but produce higher quality offspring)*Investments:-time-energy-resources-parental careII. Reproduction in life histories*Successful life history strategy-iteroparity: reproduces over and over (oak tree)-semelparity: single reproduction (salmon)-think: what kinds of natural selection pressures favor each type?*Natural selection and life history strategies-semelparous insects: predictable food, forest trees with new leaves every year-iteroparous insects: lays eggs in small batches (many a year),bet-hedging to spread These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.chance of success (predators won’t find them all at once)*We can classify reproductive patterns on -number of reproductive cycles-number of offspring-amount of parental care-sexual/asexual-advantages of sex: recombination of genes, increased ability to respond to environmental challenges-disadvantages of sex: slows down the rate of population growth, only half of the genome is passed onIII. Life tables*In our sheep example: we can determine much more about population growth by including how many females are produced by each female at each age*Fecundity can be combined with survivorship in life tables to estimate net reproductive rateIV. Population growth*Conditions for unlimited growth-unlimited environment (excess supply of resources)-population growth a maximum rate-closed system*Geometric growth: single-celled organism that reproduces exactly once per dayN1=N0(lambda) PopulationTime*Exponential growthdN/dt=rNGives us the rate of population growthWhat is r? Birth rate-death rate R varies from 300+/day to .000075-/day*Sigmoidal/logistic growthCarrying capacity dN/dt=rN