The human population continues to grow. There are several things that contribute to this growth, including biomedical progress. In this lesson, we will look at some examples as well as what may happen if this growth continues.
In a previous lesson about the theory of demographic transition, we talked about how changes in society affect the structure of the population. Two of the factors that caused human populations to change were advances in medicine and advances in technology.
In this lesson, we will look at some of these advances as well as their effects on the human population.
Before we can look at how advances in technology and medicine have affected the human population, we need to review carrying capacity.
If you have already taken ecology, you may be familiar with carrying capacity, which is the maximum number of individuals an environment can support. Keep in mind that if a population exceeds the carrying capacity, it will then decrease. Sometimes this will result in the population dying out, but it can also result in the population decreasing for a little bit but then leveling off around the carrying capacity.Now that we have gone over carrying capacity a bit, let’s relate it to something more familiar. Rather than thinking about the number of deer a forest can hold, think of carrying capacity as maximum occupancy. When you step into an elevator, you may see a sign that tells you the maximum weight allowed or the maximum number of people allowed in an elevator.Another time when you may see this is in a restaurant.
There is often a sign inside by the door that lists the maximum occupancy of the restaurant, indicating how many people are allowed to be in the restaurant. The correlation can be seen between maximum occupancy and carrying capacity because both terms relate to the maximum number of individuals in a specific area. However, do keep in mind that the maximum occupancy in an elevator or restaurant is generally issued by the fire marshal as a safety regulation, and carrying capacity involves how many individuals an area can support based on factors such as nutrition and space.
There are several things that affect the carrying capacity of a population. In ecology, we generally focus on items such as food, shelter and water. However, when talking about human populations, there may be specific items that are discussed including social and economic development.
Review of Demography
In the theory of demographic transition, we looked at the human population on the island of Dharma. Remember that demography is the statistical study of human populations. We discussed the five stages of transition and looked at factors that changed both the age structure and composition of the population. For example, when the population on Dharma was moving from stage 1 to stage 2, this was due to advances in health care causing the life expectancy to increase. By studying the population, demographers are able to predict what will happen in the future, including the predicted number of people that will be in the population or the carrying capacity of the population.
Carrying Capacity of Human Populations
Because humans modify their environment, they can alter the carrying capacity. For example, the amount of land available does not necessarily represent the number of people that could be in an area. There could be one large house with only one person living in it or, in the same area, there could be a huge apartment complex holding several hundred people. This affects the carrying capacity of the area. However, in this lesson, we will focus more on biomedical progress and its influence on the carrying capacity of the human population.
Biomedical progress refers to advances in technology and medicine.
These can range from ground-breaking revelations to practically unnoticed activities. For example, with the advent of the polio vaccine, an unimaginably devastating disease was basically expunged or removed from the population. This improved the lives of countless children as well as society as a whole. Recently, much of the focus on biomedical progress has been on genetic engineering, or the manipulation of an organism’s DNA, which is also known as genetic modification.Genetic engineering will be discussed further in another section but let’s take a look at a few examples – some are useful but others are just entertaining.
An example that visually illustrates what genetic engineering can do is seen in zebrafish, which have had the genetic information from other organisms inserted into their DNA. As we see here, the normal zebrafish is easy to miss. However, with the addition of different DNA, it is a remarkably vibrant color.A more practical use of genetic engineering is often seen in food.
You may have seen organic fruits and vegetables in your local grocery store. These products are not treated with mass chemicals and have not been genetically modified. While there are many debates about this, the focus for this lesson is on how this change has affected the carrying capacity of the human population.Because food can be modified to grow in different environments and to provide additional nutrients, this biomedical progress has increased the carrying capacity of the human population. In addition to water and shelter, people also need food. The areas where a significant amount of food can be grown are not necessarily near where people live.
With advances in genetic engineering, scientists can manipulate food to increase the nutritional value as well as the overall production of plants and animals.Aside from food, we also see advances in water. We are all taught from an early age that the earth is about 70% water. However, most of this is not fit for humans. With new technology, both the purity and the transport of water can be improved. These changes help improve the life expectancy and decrease the mortality rate.
When talking about demographic transition, water quality and sanitation were mentioned as causes for moving from one stage to the next.
Technology has helped improve living standards, which have permitted a greater number of people to live in a given area. This increase, in correlation with improvements in water and food supplies, allows the carrying capacity of the human population to increase. However, it is essential to remember that even though humans can increase the carrying capacity of an area, there will ultimately be a cap to the carrying capacity of the earth.
It is important that humans keep this limit in mind regarding the biomedical progress that is quickly changing our world.
Carrying capacity is the maximum number of individuals an ecosystem can support and includes factors such as living space, access to water and food supply. With biomedical progress, or the advances in technology and medicine, humans have altered the carrying capacity of their population. Medicine has allowed people to live longer and to prevent diseases that were previously fatal.Genetic engineering, or the manipulation of an organism’s DNA, has allowed improvements in the quality and quantity of food.
Technology has helped improve the supply, transport and quality of water. While these changes have continued to increase the carrying capacity of the human population, it is important to remember that unless future changes are made, even with these current advances, the human population will expand past the carrying capacity of the earth, eventually causing the human population to decrease.
After watching this lesson, you should be able to:
- Define carrying capacity and demography
- Explain how biomedical progress, such as genetic engineering and advances in technology, affect carrying capacity