Time delays in density-dependent responses result in poor tracking of environmental changes and oscillating populations. Agriculture and the industrial revolution increased human r. 7. A population,s age structure reflects population growth and differs between industrialized and developing countries. As a country becomes industrialized, r may remain high through the demographic transition. Only ZPG can avert global overpopulation.
Populations have limited distributions.
Within their range, most organisms are clumped together. A population is a set of individuals of the same species inhabiting one geographic area. Most species have methods to avoid inbreeding. Genetic drift, founder effect, and population bottlenecks can reduce the diversity and makeup of a gene pool. Resource limits and density-dependent factors determine the upper limit for population growth.