Age Structure Diagrams

Question 1

why don’t human populations always function like natural populations?

Answer 1

as humans we can alter our resource availability and carrying capacity

Question 2

what is on the y-axis of an age structure diagram?

Answer 2

age cohorts, groups of individuals all born within the same time period

Question 3

what is on the x-axis of an age structure diagram?

Answer 3

the number of individuals in each cohort

Question 4

how can population growth rates be interpreted from an age structure diagram?

Answer 4

by the shape of the structure

Question 5

what can be interpreted from the shape of the structure of an age structure diagram?

Answer 5

population growth rates

Question 6

how can you tell if a population is rapidly growing through an age structure diagram?

Answer 6

a rapidly growing population will have a higher proportion of younger people compared to stable or declining populations

Question 7

what are age cohorts?

Answer 7

groups of similarly aged individuals

Question 8

what are the three age cohorts?

Answer 8

0-14 = prereproductive
15-44 = reproductive age
45+ = post reproductive

Question 9

what indicates growth rate in an age structure diagram?

Answer 9

the size difference between the 0-14 and 15-44 age cohorts

Question 10

what is the growth rate of a population based on the size difference between the 0-14 and 15-44 cohorts on an age structure diagram?

Answer 10

larger 0-14 cohort = current and future growth
roughly equal 0-14 and 15-22 = slight growth/stable
larger 15-44 = population decline ()

Question 11

what are the different shapes of age structure diagrams and what do they mean? walking analogy

Answer 11

• extreme pyramid shape: rapid growth
• less extreme pyramid: slow, stable growth
• house: stable, little to no growth
• narrowest at base: declining population
• the more difficult it is to walk up a pyramid, the slower the population growth