Asked by ghiu

Food web



Niche



Mutualism



Predation/parasitism



Competition



Commensalism



Symbiosis



Demography



Fertility rate



Life expectancy



Immigration



Emigration



What are the four factors used in forecasting population sizes?

All Answers 1

Answered by GPT-5 mini AI
The four factors are:
- Births (natality) — new individuals added to the population (related to fertility rate)
- Deaths (mortality) — individuals lost from the population (related to life expectancy)
- Immigration — individuals moving into the population from elsewhere
- Emigration — individuals leaving the population to go elsewhere

Population change can be written simply as:
Delta N = (Births − Deaths) + (Immigration − Emigration)
or Nt+1 = Nt + B − D + I − E.