Chapter three in the book called The Human Mosaic : A Cultural Approach to Human Geography is aptly entitled "Population Geography." Simply put, this chapter is on the geography of population (and how population relates to geography, in general). In fact, this chapter gives significant evidence that population is placed within geographical context all throughout the earth.
In regard to discussing "Population Geography," the chapter first deals with infant mortality rate, giving a detailed map about where the infant mortality rate is highest and lowest. I am not sure why the other parts of the world are left off of this map, but for some reason The Human Mosaic only gives the mortality rates represented in South America and North America (using different colored squares). Of course, there is a much higher infant mortality rate in the less developed countries of the continent of South America.
Next, there is a significant section called "migration." Migration is simply the act of life forms moving from place to place. This can be in relation to either humans or animals. Of course, The Human Mosaic is going to focus primarily on the migration of humans.
Humankind is not tied to one local. ... We have proved remarkably able to adapt to new and different physical environments.
Therefore, there is evidence that humans can live most anywhere on the earth. Humans are not indigenous to one particular climate or ecosystem. Further, we have the evolutionary ability to adapt, or change, according to a new climate presented to us. There is an interesting map of both European countries and African countries included here with arrows representing the migration between the two places. Of course, it is the Europeans that generally "migrated" to Africa, and in the couple of preceding centuries, it was usually for the purpose of conquest and colonization (which is quite controversial).
In this same section on migration, the idea of "the refugee" is also discussed thoroughly.
Refugees [are] people who leave their country because of persecution based on race, ethnicity, religion, nationality, or political opinion.
People leave their place of origin for many reasons and, as is stated above in a direct quote, they can leave because of politics, racism, ethnicity, religious differences, or nationality.
The Human Mosaic then probes deeper into the actual subject of population. In fact, the graph of world population should surprise any onlooker, as the population was relatively low until the advent of new medical procedures (and general technology) in the last century. In truth, says Malthus, we do not have enough resources to keep up with the staggering population growth. Malthus calls this his "dismal equation." As a direct result of this idea, there are some countries who make population control (i.e. China's "one couple, one child" rule) mandatory in their country. The Human Mosaic also includes a couple of interesting visual representations of that propaganda. Environmentalism and the general protection of the environment are also discussed due to the propagation of the population.
Finally, a chapter on population would not be complete without at least a short discussion about depopulation as well. Some of this depopulation mimics migration a bit in that many subjects of the Roman Empire moved away after the empire fell. Similarly, many of the citizens of Las Vegas, Nevada moved away after the housing collapse. There is one particular statement at the end of this section that expresses the thematic content of the chapter perfectly:
The cultural landscape visually expresses the varied ways in which societies accommodate their populations.
Thus, finally, it is culture and the landscape of that culture that remain the reasoning behind the different ways populations can be accommodated in their own societies and regions.