Summary
The distribution of ages in a population, which predicts future growth.
In depth
Pyramids with wide bases mean growth (Nigeria); even sides mean stability; narrow bases indicate decline (Japan). Population momentum means growth continues for decades after fertility falls to replacement.
Planners use these pyramids for schools, healthcare and pensions.
A pyramid with a broad base indicates a high proportion of young people. Dependency ratios affect economies. Demographic transition describes shifts from high to low birth and death rates.
Key idea: age structure reveals future population trends.
Frequently asked questions
What is Age Structure?
The distribution of ages in a population, which predicts future growth.
Which area of biology covers Age Structure, and how advanced is it?
Age Structure is one of the 54 topics in Ecology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Population, Allee Effect, Limiting Factors.
Can you give an example of Age Structure?
Countries with ageing populations face labour shortages.
What should I learn before Age Structure?
Work through the Beginner topics in Ecology first, such as Ecology, Ecosystem, Biotic and Abiotic Factors, then return to Age Structure. Intermediate topics assume the Beginner vocabulary.
What topics are related to Age Structure?
The closest topics to Age Structure are Population, Allee Effect, Limiting Factors, Exponential Growth. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Age Structure?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Age Structure. To practise the whole of Ecology, use the Ecology quiz.
How is Age Structure different from Population?
Age Structure: The distribution of ages in a population, which predicts future growth. Population: All the individuals of one species living in the same area at the same time. Read both side by side and note what each one explains.
How should I study Age Structure step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Population and explain the difference aloud. Finally, take the Ecology quiz and come back to this page for any question you miss.