You might know the three basic shapes of age structures (popularly referred to as population pyramids) and what they mean. But let’s review: Why does a triangular age structure diagram reflect population growth? And what about a rectangular graph means a population is
stable? Here is where we need to look at categories of female reproduction. We focus on the fertility of women, because they are the ones who carry and give birth to new little humans (though we all know they can’t do it on their own!). It is commonly accepted that a woman’s years of reproduction fall into the following three categories: Pre-Reproductive: Birth to age 14 years – These are ages when most girls are pre-pubescent and unlikely to have the ability to bear children. But their fertile years are still in the future, they just haven’t gotten there yet. Reproductive: Age 15 years to age 44 years – These are commonly referred to as the child-bearing years. It’s the ages when females are most fertile and most likely to bear children. Post-Reproductive: Age 45 years to end of life – These are the years during which females’ fertility declines and bearing children again becomes unlikely. Their fertility will not increase again in the future. *It is important to note that the age divisions between reproductive groupings are not hardline rules. Girls 14 years old and younger, and women over the age of 45, can and do bear children. And some women between the ages of 15 and 44 years old are not able to bear children. These groupings are based on averages of the ages at which most females are at the height of their fertility. What Do Reproductive Years Have to do with Age Structure Diagrams?Let’s looks at some real-world data and explore. The age structure diagrams below have been color coded to show the three reproductive categories. Example of an age structure with an expanding populationExample of an age structure with a diminishing populationExample of an age structure with a stable populationAbout Population EducationPopulation Education provides K-12 teachers with innovative, hands-on lesson plans and professional development to teach about human population growth and its effects on the environment and human well-being. PopEd is a program of Population Connection. Learn More About PopEd. What can be interpreted from an age structure diagram of a country?An age-structure diagram provides a snapshot of the current population and can represent information about the past and give potential clues about future problems. When you are interpreting age-structure diagrams, it is important to compare the width of the base to the rest of the population.
What does an age structure diagram show?One of the tools that demographers use to understand population is the age structure diagram (it is sometimes called a population pyramid, but it is not always pyramidal in shape). This diagram shows the distribution by ages of females and males within a certain population in graphic form.
What describes the shape of an age structure diagram for the US?A population pyramid (age structure diagram) or "age-sex pyramid" is a graphical illustration of the distribution of a population (typically that of a country or region of the world) by age groups and sex; it typically takes the shape of a pyramid when the population is growing.
Which age structure diagram best depicts the ages in a population?However, the use of a population pyramid is considered the best way to graphically illustrate the age and sex distribution of a given population. A population pyramid, using a paired bar chart-type graphic, shows the numbers or percentages of males and females in each age group.
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