BACKGROUND • Populations are interbreeding groups; members of the same species in a particular area • Populations are dynamic; changes due to: natality (births) mortality (deaths) immigration (moving in) emigration (moving out)

growth rate constant, regardless of population size linear growth growth rate constant, regardless of population size 25 20 15 10 5 Small or large population, growth rate stays the same 500 1000 1500 2000

Linear growth is additive EX: Assume a growth rate of 2 offspring per generation: 10 mating pairs +2 = 12 +2 = 14 +2 = 16

growth rate proportionate to population size exponential growth growth rate proportionate to population size Large population rapid growth +24,000 gen Small population size, slow growth + 500 /generation Fun fact: doubling time is the rate divided by 69. EX: 3% growth rate /69 = 23 years to double

Exponential multiplies Assume a growth rate of 2 offspring per mating pair 10 mating pairs +20 = 30 +60 = 90 +180 = 270

Analogy – Making the most out of saving $ As the ‘pot’ increases, so does the rate of growth Size of savings account has no impact on rate

Which describes populations? populations have great biotic potential because they experience exponential growth