Practice question

With nonoverlapping generations and a constant net reproductive multiplier, abundance follows Nt = N0R0^t. Starting with 500 females and using R0 = 1.5, four successive generations give 500 × 1.5^4. Because 1.5^2 = 2.25 and 1.5^4 = 5.0625, the projected female population is 500 × 5.0625 = 2,531.25. Fractional individuals are acceptable as a deterministic expectation; an actual census would necessarily be an integer. The calculation assumes that R0 remains unchanged, generations are discrete, density dependence is absent, and the age structure can be represented by a single generation multiplier. It also treats the initial and projected counts as females, consistent with female-based life-table calculations. A common error is applying the multiplier only three times or multiplying 500 by 1.5 × 4, which treats multiplicative growth as additive. Repeated reproduction compounds population size, so each generation’s increase is calculated from the enlarged population inherited from the previous generation. This projection is therefore a compounded expectation across four full reproductive transitions.