Understanding Patterns in Population

Over time, populations increase, become stagnant, and decrease at varying rates. In this lesson, we'll explore how to identify those trends in population using the tools of demography – a subfield of geography that studies trends in populations. By the end of this lesson, you'll be adept at analyzing demographic trends using tools like the Demographic Transition Model (DTM), population density maps, and population pyramids.

Guide Point 🧭

Demographic Transition Model (DTM)

The demographic transition model showing birth rate, death rate, and total population changing through five stages. A model is a smaller representation of something larger. Think about a model train. It isn’t a full-size train and does not operate identically to a full-size train. It is a model of a full-size train and operates similarly. In a comparable way, the DTM is a model of a theory about how populations change over time. It’s not exact or perfect for any population, but throughout history, most populations have progressed through these stages.

Created by British demographer Warren Thompson in 1929, and updated in 1945, the Demographic Transition Model (DTM) serves as a roadmap for understanding how populations change over time. Picture a country transitioning from a traditional society to a modernized one as you follow along by looking at the chart while reading.

👀 See if you can identify each stage.

Demographic Transition Model | Practice Activity

In the activity below click the number to learn more about each stage.

Understanding these stages helps demographers anticipate population changes across different regions and assist policymakers in planning accordingly.

Guide Point 🧭

Population Pyramids

Population pyramids are graphical representations of a population's age and gender distribution. They typically consist of two bar graphs, one representing males and the other females, arranged in age cohorts, or groups. Population pyramids allow demographers to identify trends such as population growth, aging populations, and changes in fertility rates over time. They also help policymakers anticipate future social and economic challenges associated with shifting demographic structures, such as healthcare needs, labor force participation, and pension systems.

Let’s examine some population pyramids that represent countries in different stages of the DTM. This should help us understand the two better and see the connections between them.

There are no modern-day countries in stage 1 of the DTM. Therefore, we have no example population pyramid to examine. Populations in stage 1 are largely hunter/gatherers, living nomadic lifestyles. They are underdeveloped and only progress from stage 1 with the Agricultural Revolution – a significant shift in human society marked by the transition from hunting and gathering to farming and domestication of plants and animals, leading to settled communities and the development of agriculture as the primary means of food production. There will be more about the agricultural revolution in a future lesson in this course.

Population Pyramids | Practice Activity

Read the presentation below about population pyramids. Click the arrows on the bottom right to progress through the presentation.

Guide Point 🧭

Population Density Maps

Map of global population density. Population density maps provide visual representations of where people are concentrated in an area. Look at the population density map of the world. The cartographer – or mapmaker used darker colors to represent greater population density. These maps offer insights into the distribution of human populations and the factors influencing it.

For instance, regions with fertile land, favorable climates, or access to waterways tend to have higher population densities. Urban areas typically have higher population densities due to economic opportunities and infrastructure development. By analyzing population density maps, we can identify patterns of urbanization, rural depopulation, and regional disparities in population distribution.

Reflection

As we conclude this lesson, reflect on the tools for identifying demographic trends, like the Demographic Transition Model (DTM), population pyramids, and population density maps. By exploring the complexities of population growth, you're better equipped to comprehend the demographic trends shaping our world. In our next lesson, we'll explore the effects of pro and anti-natal policies on population characteristics. Get ready to go even deeper into the factors influencing population trends!

How Populations Grow and Change| Video

For more about how populations grow and change, watch this Crash Course video. It is the perfect segue between this lesson and the next.

[CC BY-NC-SA 4.0] UNLESS OTHERWISE NOTED | IMAGES: LICENSED AND USED ACCORDING TO TERMS OF SUBSCRIPTION - INTENDED ONLY FOR USE WITHIN LESSON.