Life for mountain people, as a rule, has always been a challenge. For
this reason, it might appear that if given a choice, humans would
perhaps tap the wealth of the mountains — such as their minerals,
forests, their possibilities for tourism, etc. — but not live there
permanently.
However, human association with the mountains is
almost as old as their relationship with the sea. The terms of life are
usually much harder for humans at high altitudes and are controlled by
three important factors: the terrain, the climate (including the thin
atmosphere), and the isolation from the rest of mankind.
Yet despite all of this, higher elevations in the tropics may be the
best habitat for humans in these areas. They are free from malaria,
sleeping sickness (African trypanosomiasis), and other diseases of the
hot lowlands.
In many highland areas near the equator there is no
such thing as changes of seasons, as most of us are used to. In these
areas the climate is springtime all year, and fields yield several crops
annually. In fact, it is this type of environment in the Bolivian and
Peruvian Andes that led to the only great civilization to be found at
high altitudes — the Incas.
In the last 4,000 years millions of people have lived in the high valleys of the central Andes, and
many of them established some of the highest permanent habitations on
Earth. However, most of these are below 13,000 feet (3,962 m.), as even
near the equator it just gets too cold and the air too thin above this
altitude to be very suitable for most people as a permanent habitation.
Most
humans live near the bottom of a 62-mile deep ocean of air that we call
the atmosphere (99.999 % of the atmosphere’s gases are found below 62
miles; the small amount of gases above this are detectable out to about
300 miles).
Because of all this weight of air above the Earth, the
pressure of it pushing against our bodies at sea level is about 14.7
pounds per square inch (PSI).
This pressure is critical for
getting oxygen into the blood stream, as it forces the oxygen through
the thin membranes in the lung capillaries of the alveoli (air sacs) and
into the blood by a process known as “passive diffusion.”
For the rest of the story: http://www.mountainprofessor.com/mountain-people.html


