10Survivorship curves plot the proportion of individuals alive at each age 100Type I10Type IIPercentage of survivors (log scale)1Figure 36.3 Three types of survivorship curves.Type III0.150100Percentage of maximum life span
13Rabbits Time (months) Population size (N) 1 2 3 4 5 6 7 8 9 10 11 12 12345678910111250100150200250300350400450500Table 36.4A Exponential Growth of Rabbits, r = 0.3.
14Bacteria and opportunistic microorganisms follow an Exponential Growth model Lag phase: recovery from low metabolic state, cells “gear up” their enzymesLog phase: exponential expansion when nutrients are not limiting and conditions are rightStationary phase: growth slows due to lower nutrients or oxygen, or buildup of waste productsDeath phase: cells die more rapidly with toxic wastes or acidic pH
15Exponential growth Sudden decline Number of aphidsFigure 36.5B The effect of an abiotic factor (climate) on aphid population size.AprMayJunJulAugSepOctNovDec
22per 1,000 population Birth or death rate 504030per 1,000 populationBirth or death rateRate of increase (r)20Birth rateDeath rate10Figure 36.9B Demographic transition in Mexico.1900192519501975200020252050Year