Interpreting Age Structure
Diagrams
Populations
Explain why the one on the left is an example of
zero growth and the one on the right is an
example of negative growth.
Based on the age structure diagram, what can you assume
about the life expectancy in this country?
If Papua New Guinea’s life expectency increased over the
next 20 years, what affect would that have on their
population and how would that change the age structure
diagram?
Using the diagram, explain why Sweden has a stable
population (no growth or decline)?
Survivorship Curves
• A graph showing the number or proportion
of individuals surviving at each age for a
given species or group (e.g.
males/females
• 3 types
– Type I high survival in early and middle life
and then rapid decline.
– Type II steady mortality rate regardless of age
– Type III high rates of mortality early on in life
What influences the survivorship
curves?