Human adaptations to higher altitudes
High altitude has a positive and negative effect on humans.Higher elevation interrupts homeostasis in several ways. When we breath air at sea level atmospheric pressure is about 14.7 pounds per square inch which allows for oxygen to easily pass through our lungs and into the blood. At higher altitudes low air pressure makes it harder for oxygen to enter the cardiovascular system. This is called hypoxia which can be referred to as oxygen deprivation. Other side-effects of this include lack of appetite, vomiting, headache, distorted vision, fatigue, and difficulty with memorizing and clearly thinking. There is also an increase in heart failure due to the amount of stress on the lungs. A positive effect that this has is "researchers from the University of Colorado School of Medicine and the Harvard School of Global Health reported that people generally live longer at high altitudes and have a lower risk of dying from coronary artery disease. This positive effect occurs unless people have chronic breathing problems.The researchers speculated that mild hypoxia improves the way the heart functions and produces new blood vessels that increase blood flow for the heart. An alternative explanation presented by the authors is that increased exposure to ultraviolet radiation from the sun at higher altitudes increases the body's ability to produce vitamin D, which has beneficial effects on the heart."
With short term adaptation there is an increase in breathing and heart rate to as much as double, even while resting. Pulse rate and blood pressure go up sharply as our hearts pump harder to get more oxygen to the cells
With faculative adaption and higher altitudes, humans can adapt fairly quickly to shifts in the density of oxygen. For example the primary solution for the Indians in the high mountains of Peru and Bolivia resolved to producing more hemoglobin which allows them to expand their lungs more.
You can see Developmental adaptions in the people of A recent study of Tibetan who live their lives at around 15,000 feet has shown that they have 10 oxygen-processing genes not commonly found in lowland populations.
Cultural adaptations are seen with with climbers who use the tool of oxygen tanks to help them reach really tall peaks of mountains which cannot be reached without extra oxygen.
By studying all these different types of adaptations we can see how amazing humans are and what we are capable of! We can adapt and change to live in harsh environments that can positively effect us. For example this effects us in a productive way with the athletes in the Olympics because they train at higher altitudes for months so when the go back down to sea level their lungs are expanded to the hemoglobin.
We cant use race to understand the variations of these adaptations because race has no genetic basis. It is better to look at these as environmental influences on adaptions because most humans can achieve what these people achieved that live in these harsh climates.
Very good opening description of the high altitude stress.
ReplyDeleteGood explanation on your short term adaptation.
"For example the primary solution for the Indians in the high mountains of Peru and Bolivia resolved to producing more hemoglobin which allows them to expand their lungs more."
Yes, but populations in the mountains of Peru and Bolivia would be demonstrating long term developmental adaptations, correct? Facultative are exhibited individuals moving into a high altitude environment and remaining there long enough to develop facultative traits. An increase in the number of red blood cells (and the hemoglobin that goes with them) is a facultative trait. Just understand that you wouldn't see this adjustment in high altitude populations. They would have that trait from birth.
Good explanation for the benefits of the adaptive approach.
"We cant use race to understand the variations of these adaptations because race has no genetic basis."
Correct. That is all the explanation that was really necessary. Good.
I enjoyed reading your post. I didn't know people used oxygen tanks to facilitate in mountain climbing. I also agree with you that we can't use race to understand the variations of adaptations. Good post.
ReplyDelete