Life at High Altitudes - Essay Example

How successfully, and by what means, have human populations been able to overcome the challenges of survival, functioning, reproduction and growth at altitudes over 3,000 metres above sea level? Name of Author Name of Supervisor Date Introduction Sea levels are gotten when the distance between the high tide and low tide is measured and divided by two. It forms the base for which elevation is measured when it comes to land. The elevation of land is measured by the distance of the surface of the ocean (sea level) to the surface of the earth (land) (Microsoft Encarta 2007). When the distance of elevation between the land or atmosphere and the sea level is measured, it is called Altitude (Microsoft Encarta 2007). As we climb higher in altitude, we notice that, among other elements, the atmospheric pressure is increasingly altered. The air decreases in pressure and is cooler as you go further away from the sea level. This is caused by two main factors: gravity and atmospheric heat. Gravitational force acts on the air molecules to pull them nearer to the ground (Atmospheric Pressure 2000). Due to lower atmospheric pressure, humans and animals have difficulties living at certain altitudes high above sea level. As we go further away for sea level, we notice that at high altitudes there is partial pressure of oxygen (Peacock 1998). This level is also attributed with some kinds of lethal sicknesses, which includes: high altitude cerebral edema, altitude sickness, and high altitude pulmonary edema (Cymerman and Rock 1994). As humans and animals climb high in altitude, there is an increasing urge for adapting to the change in atmospheric pressure. This becomes possible with the fact that the change in altitude and atmospheric pressure alter breathing rate, heart beat rate and blood chemistry (Muza et al 2004). It takes days, if not weeks, months or even years to adapt to this environment. But as the ascension increases above 8,000 metres, living beings find it difficult to adapt and then will, sooner or later, die. This is called the Death Zone (Clark 1998). Life at High Altitudes Life at high altitudes has been seen to be slightly different from that at sea level. This is where adaptation and mutation come into play. To live at high altitudes, it is noticed; people alter in body chemistry to adapt. People living at high altitudes have different ways of adapting to their environment. Another interesting fact is that they have natural abilities that are exceptional to them alone (Mayell 2004). Below are three different groups of people in three different environments but with one common similarity – they all live at high altitudes. They have adapted to their environment differently. These people are; the inhabitants of the Andean Altiplano, the inhabitants of the Tibetan Plateau, and the Ethiopian Highlanders. These are three different groups of people all living at high altitudes but with different ways of adaptation to their environment. While the Andean Altiplano is situation in America, the Tibetan Plateau is in Asia, and the Ethiopian Highlands are in Africa. The Andean Altiplano Altiplano is a Spanish word and it means High Plateau. The Andean Altiplano is found in western central South America. It is an area of widely spread highlands and it’s the only one of its kind found outside Tibet (Antofaya 2010). Location of the Altiplano The Altiplano is approximately 3,750 in average, which lives it faintly less than that of Tibet. It is situated in the centre of the Andes, covering a portion of Argentina, and North of Chile, South of Peru and West of Bolivia (Muller & Schwarzen 2004). It is an area with enormous active volcanoes. On the south-western part of the Altiplano is the Atacama Desert, which boasts of being one of the driest deserts on earth. And the east side of the Altiplano is the humid Amazon rainforest (Antofaya 2010). Climate on the Altiplano The Altiplano is so famous for its height and climate that sometime it is interchanged with the phrase Altitude Zone. The Altiplano climate is so cold that it has been said to be colder than tierra fria but not tierra helada (Bolivia Climate 2010). The Tibetan Plateau Standing tall in the middle of central Asia is The Tibetan Plateau. On one side, it covers much of the Tibet Autonomous Region and Qinghai Province in china and on the other side it covers Ladakh in Kashmir, India. It is situated on a land mass of over 1,000 by 2,500 kilometres. It has a height of approximately 4,500 in average and it is sometimes referred to as ‘the Roof of the World’. It boasts of a reputation among plateaus of being the highest and the biggest. It has an area of about 2.5 million square kilometres (Yee 2005). Around it is an array of mountain ranges. Near the south of the plateau a River valley cuts across the plateau. Forested gorges and ridges of mountainous headwaters of rivers could be seen on the eastern and south eastern part of the plateau. And finally, a range encompasses the plateau in the west. On the north, the Tibetan plateau has a cliff of about 9,000 – 7,000 feet. Mountain ranges and large brackish lakes could be found on the plateau (Yang & Zheng 2007). Climate on the Tibetan Plateau As would be expected, the climate on the Tibetan Plateau is cold. It has low rainfall making it have a vast area of almost treeless land. Dry grass and grass cover could also be seen on the surface of the plateau. Falling mainly as hailstorms, the plateau has an annual precipitate range of about 100mm to 300mm. Although on the southern and eastern edges of the steppe grassland could be found for sustaining nomadic herdsmen (which is normally frozen for six months of the year), the vast portion of the plateau is normally permanently frozen for most time of the year (Tibet climate 2010). The north and northwest of the plateau alone has an average height of 5,000 metres. This side of the plateau is actually the highest part of the plateau therefore making it the colder and drier from the rest of the plateau. The Ethiopian Highlands Situation in Eritrea, Ethiopia, the Ethiopian Highlands are an uneven collection of mountain. It stands at the Horn of Africa, Somalia. Eritrea Highlands, as it is sometime referred to, is an enormous uninterrupted area of vast highlands and only one of its kinds on the continent. For this reason, it is called the Roof of Africa. With its lowest surface below 1500 metres and its summit reaches a staggering height of 4550 metres (Henze 2000). Genetic Link, Success to Living at High Altitudes Living at high altitude is very different from living at sea level. At high altitudes, there are cold temperatures and low atmospheric pressure, but to mention a few. All these, and a lot more, constitute to the threat of living at high altitudes. Researchers have discovered that living at high altitudes could cause some level of mutation while trying to adapt to the environment. They also discovered that the ability to do well at high levels could be genetically inclined. Discovery News (2004) states that according to Swiss National Science Foundation, adaptation and associated physical activities by human being on a high altitude seems to be genetically linked. The website went further to state that this could aid in the explanation of the phenomenon of why some people experience no actual negative effects in high altitudes but others do. According to them, a research project led by Sport physician Han Hoppeler of the University of Berne in 1980 showed the fitness differences of members of two Swiss Everest expeditions. He discovered that while some climbers possessed little or no damages others had cell damage in their muscle tissues. The experiment involved examining climber porters from Sherpa (member of Himalayan people) and lowlands. At the end of the examination, Hoppeler discovered that the climber porters from Sherpa where not affect by the altitude to which they had climbed but those from the lowlands had drastic damages to their muscle cells (Discovery 2004). O’Neil (2010) supports this idea, he states that though lowland people are the ones that are drastically affected by the change in altitude whenever they climb to high altitudes, the highlanders’ have learnt to acclimatize to the altitude through thousands of years of adaption and have passed it on to their offspring. This is the reason why people of the Tibetan Plateau, The Andean Altiplano and The Ethiopian Highlands can live comfortably at such altitudes. Adaptation Differences at High Altitudes It has been discovered that at different locations people have adapted to high altitudes in different ways. Definitely, the ancestors of most highlanders had problems adapting to the climate at first. But with time they adapted to their environments in their own ways. In Adapting to High Altitudes, O’Neil (2010) emphasis this, he states that due to natural selection over thousands of years, people have adapted to their harsh environment at high altitudes. And, more intriguing, is the fact that they do so differently. He went further stating that the increased production of haemoglobin in the blood of the Peruvian and Bolivian has helped them to increase their lung expansion capability. These effects give them more blood in their body. To the Tibetan and Nepalese, O’Neil (2010) states that they have broad arteries and capillaries, and breath rate is faster than people at sea level in order to take in more oxygen. They have mutated this way because, though they still have a normal level of haemoglobin as compared to people at sea level, their blood flow would be higher and this would eventually lead to greater amounts of the blood getting to the muscles. It has also been noticed that due to the nature of their environment, the Tibetans have 10 oxygen processing genes (EPAS1). Researcher Mayell (2004) supports this idea too. She states that in the Andes, the inhabitants adapt to their environment by adsorbing more oxygen in their red blood cells. That is to say, they distribute oxygen round their body more effectively than lowlanders even though their breathing rates are the same. Mayell (2004) writes that in the case of the Tibetans it is very different. For them, she states, their breath intake per minute is the differences. She states that they take in more oxygen in a minute compared to lowlanders. Another feature is the fact that they have expanded blood vessels which enhances the delivery of blood round their body compared to lowlanders. Tibetans have the ability to synthesis nitric oxide from the air. This gas helps to expand blood vessels in the body. In addition to these two sets of people, Mayell adds a third – the Ethiopian Highlands. In this case, it remains a mystery what makes them survive at such high altitudes. Mayell discovered that the inhabitants of the Ethiopian Highlands neither breathe faster nor synthesis nitric oxides more effectively like the Tibetans. Nor are they like the Andeans who have higher haemoglobin. She states that science hasn’t discovered how they do it yet. Reproduction at High Altitudes Adapting to a new environment means undergoing changes in order that people might be able to function properly in the environment. Among these numerous functions is Reproduction. Researches have proven that amidst the harsh environment, indigenous highlanders are not affected, when it comes to reproduction rate. And no other person expresses this better than researcher Vitzthum (2001) of Binghamton University. In an experiment carried out in Bolivia Altiplano. Vitzthum gathered people from 30 communities around La Paz and Oruro which were situated almost 200km away from each other. The results showed that when compared to the average woman, the highlanders possessed no significant difference when it comes to ovarian cycle length and probability of ovulation as inferred from progesterone levels. Vitzthum lamented that hypoxia is not likely to affect reproduction pattern if there seem to be a drop in fertility levels shown by the high altitude populations when it comes to these two mechanisms. This proves the Flexible Response Model right; it predicts that even though newcomers to high altitudes find it difficult to reproduce, the Andean women would, successfully. Nevertheless, hypoxia seems to still have some level of effect on women living at high altitudes, even the highlanders. One of these effects is the fact that there is an increase in fetal loss. The results also showed variation in infant feeding practices among Andean populations, even though no difference was noticed in the coital frequency (which determines the probability of insemination). This could be a reason for any observations noticed in the reproduction pattern of the Andean women (Vitzthum 2001). Growth Rate at High Altitudes In a reviewed work on three different groups of highlanders in three different locations, Pawson discovers that although environmental conditions may seem similar at all highlands, growth patterns cannot be judge by them alone. Studying Peruvian children at about 3500 m, statistics show that they have slower growth rate, reduced birth mass, poorly defined adolescent growth spurt, longer overall period of growth, and delayed onset of certain aspects of psychomotor development. Scientists wonder, whether or not, this is due to developmental acclimatization to hypoxia or genetic (Pawson 1976). Studying the Ethiopia Highlanders, Pawson discovers an intriguing difference with the statistics this time. He discovers that the children of the highlanders are taller, heavier and mature earlier than lowlanders who are similar to them in genetics. He stated that this could be as a result of the environmental variables, such as high rate of infectious disease at the sea level and that hypoxic stress expressed on the Ethiopian Highlands is not as harsh as to affect growth (Pawson 1976). To be more convinced Pawson did another survey on the Tibetan people living in Nepal. After collecting data from various people, he discovered that genes could be the mother influence behind the growth patterns of the Nepalese children (Pawson 1976). Finally, at the end of the whole survey, Pawson (1976) postulates that he agrees with the fact that hypoxia and other environmental factors could stimulate some growth parameters, but the results of the different locations on their inhabitants are not similar. He went further to state that genetic more than environment was responsible for the rate of growth by the different highlanders. Conclusion Though living at high altitude may be dangerous to some people, there are still people who have made it their homes. The high altitude is so dangerous that sometimes, it feels like a wild animal come at you. The facts show that adaptation and mutation has been the mother success to the survival at high altitudes. It shows that with adaptation the highlanders are been able to function and reproduce at these high altitudes. Looking at the facts closely, it shows that genes more than environment is the reason for growth at high altitudes. This would be ironic because it would have been expected that the environment play a vital role on the growth pattern of the people living there. Finally, success at high altitudes is based on mutation, good genes and endurance. Reference Antofaya Expedition (2010). Available from: http://www.antofaya.com/altiplano/ [Accessed 20 September 2010] Atmospheric Pressure [internet]. available from: [Accessed 20 September 2010]. 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(2004) Altitude Acclimatization Guide. Army Research Inst of Environmental Medicine Natick Ma Thermal and Mountain Medicine Division. Available from [Accessed 20 September 2010] O’Neil, D. (2010) Adapting to High Altitudes [internet]. Available from: [Accessed 20 September 2010]. Pawson, I. G. (1976) Growth and Development in high altitude populations: a review of Ethiopian, Peruvian and Nepalese studies. Available from: [Accessed 20 September 2010]. Peacock A. J. (1998) Oxygen at high altitude. British Medical Journal October 17; 317(7165): 1063–1066. Tibet Climate – Best Time to Visit (2010) [internet]. Available from: [Accessed 20 September 2010] Vitzthum, V. J. (2001) The home team advantage: reproduction in women indigenous to high altitude. The Journal of Experimental Biology 204, 3141–3150. Yang Q. & Zheng D. Tibetan geography [internet]. Available from: < http://books.google.com/books?id=4q_XoMACOxkC&pg=PA6&dq=%22South+Tibet+Valley%22&output=html&sig=ycLxM4KhdjVGjXem769oQyBwpFE > [Accessed 20 September 2010] Yee D. (2005) The Tibetan Empire in Central Asia: A History of the Struggle for Great Power among Tibetans, Turks, Arabs, and Chinese during the Early Middle Ages [internet]. Available from: [last accessed September 20, 2010]. Read More