Limits on food, shelter, water, and space can have a severe impact on populations. When resources become scarce, competition for those resources increases, leading to increased levels of stress among individuals in the population. This can cause an increase in mortality rates due to increased predation, disease, and parasitism. Populations can also become more vulnerable to environmental changes as resources become more limited. This can lead to reduced reproduction, resulting in a decrease in population size. In extreme cases, these limits can lead to extinction.