Week #8 - Human Variation & Race Blog

  HIGH ALTITUDE

WELCOME TO CUZCO, PERU

CITY OF THE INCAS, IN THE COUNTRY WHICH I WAS BORN IN

ENVIRONMENTAL STRESS

Although recent studies have led researchers to speculate that people living in high altitude areas generally live longer and have a lower risk of dying from coronary artery disease, the mechanisms that maintain homeostasis evolved at lower altitudes. Therefore, high altitude negatively impacts the survival of humans by disturbing homeostasis. At high altitudes there are factors that produce stress on our bodies; hypoxia, which affects the heart, lungs and brain being the most stressful. The percentage of oxygen available at high altitudes remains the same, but the lack of atmospheric pressures (less concentrated) is the cause of fewer oxygen molecules available with each breath. This is in turn affects how our bodies respond physiologically (increase in breathing, and heart rate even while resting), hinders our ability to perform physical activities without fatigue, and causes symptoms such as lack of appetite, vomiting, headaches, etc. 

ADAPTATIONS

SHORT TERM:

A short term adaptation to high altitude happens when the lack of oxygen causes the heart to beat faster, the stroke volume (volume of blood pumped from one ventricle of the heart with each beat) to decrease, and the suppression of non-essential bodily functions (optimizing immune system, sexual function). This in turn causes a decline in the efficiency of food digestion.

FASTER HEARTBEAT

FOOD DIGESTION

FACULTATIVE ADAPTATION: 

An example of a facultative adaptation to high altitudes, is the response to the reduction in atmospheric oxygen. This response enables the production of additional red blood cells and capillaries to carry more oxygen. This causes the lungs to enlarge and it facilitates the lungs ability to transfer oxygen and carbon dioxide.  

DEVELOPMENTAL ADAPTATIONS:

Developmental adaptation occurs when their is a gradual change in the DNA of a population. These changes occur because people have been living in a specific environment for thousands of years. In the case of the people that inhabit Cuzco, Peru, a high altitude city, they are able to produce more hemoglobin in their blood and have increased their lung capacity. These changes result in an increase of oxygen that is carried by the blood, which allows them to live and reproduce in this environment.

 

CULTURAL ADAPTATION:

Cultural adaptations aid in the adaptation to stressful environments. These adaptations are unique to that culture, and entail a variety of traits which include tools, diet, social practices, clothing styles, etc. Drinking lots of water help prevent dehydration. The people of Cuzco, will drink lots of coca tea which gives them energy needed to perform in their high altitude environment and will also make their clothing out of the llama wool (very warm material).

MATE DE COCA

WARM CLOTHING

 

BENEFITS OF STUDYING HUMAN VARIATION

There are many benefits to studying the affects of high altitude environmental stresses and the adaptations to this specific environment. I was 16 when I went to Machu Picchu, I remember being excited about going on this trip and seeing a part of Peru's history, unfortunately, I was not focusing on how my body would react to the high altitude environment. Although I drank lots of coca tea when I first got there (something recommended to prevent sickness, lol I don't think so), I still became very sick. Perhaps I did way too much during the first few days of my stay.  Had I known about the effects, I would have done things different, especially while preparing for the trip and during the first few days. Luckily, with time, I was able to get back up on my feet, and enjoy the wonders the city had to offer. 

Also, both of my children have played volleyball in very competitive settings (Jr. Olympics and Festivals). These club teams have taken us to many parts of this country. When training for these events and depending on the location, my kids have had to prepare (prior to arrival) for high altitude environments. They also knew what they had to do once they got there.

In other words, I feel that the study of high altitude adaptions helps tremendously. In my experience it helps when traveling and when exercising. 

UNDERSTANDING THE VARIATION IN ADAPTATION

In my opinion, race should not be used as a means to understand variation of the adaptations I have listed above. There is no connection between race and the way ones body adapts to high altitude environments. I think I am a perfect example of what a mistake it would be if one where to study my race as an attempt to understand how one reacts to this environment.  On other hand, the study of environmental influences on adaptations is a better way to understand human variation because it helps us understand humans and how they adapt to different environments.