Deck 11: The Present and Future of Human Evolution

Question 1

Will robotics and increased mechanization of manufacturing processes reduce the need for physical activity and thus initiate changes in our body form?

Answer 1

Countries such as the United States, Japan and Canada are categorized as high-HDI (Human Development Index) countries, an index developed by the United Nations that consider the variables that combine economics, life expectancies, education and standards of living. The higher the HDI, the more advanced and developed a country will be. High-HDI nations typically have lower rates of daily activity, prolonged sitting and little physical activity. Combined with poor dietary patterns and social pressures, pronounced physiological consequences including reduced fertility, circulatory disorders and hypertension are common and detrimental.
The effects of both the advancement in technologies (emphasizing on robotics) and the increased mechanization of manufacturing processes, primarily from high-HDI countries, will lessen physical activities for humans and initiate change in the human body form, but will not have an impact from an evolutionary stance.
 
Consider that technology and increased mechanization serve to bring humans convenience and with convenience, humans will lack physical activity and therefore gain weight and increase their risk of health problems associated with the sedentary lifestyle. The differences across and within populations in both morphology and behavior result in part from differences in the convenience provided by technology and increased mechanization. It can be assumed that the more convenience provided to a population because of its high-HDI, the more sedentary its lifestyle and thus, its morphology and behavior will be dramatically different that another population with a low-HDI. With this in mind, the physical variation in the way the humans' bodies look is not due to selective differences, but to the lifestyles' impact on the existing physiology of the individual within that population.
 
In other words, advancement in technologies and increased mechanization of manufacturing will initiate change in the body form by making humans overweight and subjected to other health risks, but such changes will not be passed on to future human generations.

Question 2

In an evolutionary sense, is there a difference between a cure for HIV/AIDS and drug therapies that allow infected humans to remain alive for 20+ years postinfection? What behavioral and reproductive impacts might each of these prospects have?

Answer 2

From an evolutionary sense, there is no difference between a cure for HIV/AIDS and drug therapies that allow infected humans to remain alive for 20+ years post infection. The reason being that virulent pathogens, such as HIV, are meant to infect and kill its hosts and with the advent of modern medicines, the virus' selective impact on humans is being reduced. In other words, it does not matter if humans cure HIV or prolong the lifespan of those infected with HIV; humans are hindering the virus' selection and keeping it from removing those in the population that are unable to survive the infection.
 
In fact, those who are infected with HIV have prolonged lives and are able to reproduce, countering the goal of natural selection. It should be noted that natural selection is how an environmental stress (over time) acts upon the traits of a population and the ability of traits to be passed on to offspring. In the case of HIV infection, the virus should typically kill those who are unable to survive and those who do survive are able to pass traits that resist the viral infection to the offspring. However, modern medicines reduce the virus' selective impact and allow those subjected to the virus to reproduce, when from an evolutionary perspective, those infected should not be able to. The behavioral impact on society from the ability to prolong death, from an otherwise deadly infection, could be one of carelessness, indifference and ultimately, disrespect of a selective pressure such as HIV.

Question 3

If the same diseases are having very different effects in different human populations, can that be driving the frequencies of alleles in these populations further apart? Think about this in the context of globalization of economies and migration.

Answer 3

The same diseases can have very different effects in different human populations. This may be due to the differences in cultural patterns affecting the strength and impact of the environmental pressure (or in this case, the disease). The globalization of economies has unevenly distributed wealth throughout the world and as a result, certain countries have better economies, and therefore have better health care, life expectancies and standards of living than other countries. The ability for some populations to migrate to developed countries in an effort to receive better health care is another cultural pattern that also affects the strength and impact of diseases. As a result of such modern cultural variables, not all humans have access to the same medical technologies and thus, diseases (such as HIV) are having different evolutionary impacts on different human populations.
 
For example, in under-developed countries such as Africa, HIV (and AIDS) is considered a fatal disease, primarily of young adults. In developed countries such as the Unites States, Canada and Japan, AIDS is a chronic condition for people who have access to effective health care. The disease that kills the infected and hinders reproduction in one country is the same disease that is held at bay and treated in another country, where people still thrive and reproduce. This fact implies that different populations are under distinct pressures from disease, not from any underlying genetic composition or biological factor, but because of socioeconomic and geopolitical factors. From the socioeconomic and globalization perspective, the impact of diseases under such discrepancies will drive the frequency of alleles in these populations further apart.

Question 4

If humans are so successful at using technologies to deal with environmental challenges, does it mean that natural selection is not truly impacting us any more? Attempt to identify a few arenas where selection can still be actively impacting human allele frequencies.

Question 5

How do your own dietary habits and body modification impact your morphology? What, if any, long-term implications might these patterns have for you? For the population you live in?