CO2 and Oxygen in Evolution of Air on Earth and Health
Video: Evolution of
Air Causes Chronic Diseases and Low Cells Oxygen due to Low Carbon Dioxide.
How is it possible that a human being, one of the smartest species on
Earth, can kill itself, and over 90% people die this way, by overbreathing?
Is it nature so silly to create this way? In order to answer these questions
we need to consider changes in air composition on Earth and CO2 and O2
evolution. When there were no life on Earth, air has no oxygen (since oxygen
is a very reactive substance), while CO2 was a part of the volcanic gases that
formed air during those times. Geological studies suggest that CO2 concentration
was up to 10-12% or even more.
Thus, when the first organic substances and life forms appeared on Earth
(from about 5 billion to 1 billion years ago), our atmosphere did not have
any measurable amounts of O2, according to Professor Maina (Maina, 1998), who wrote the book The gas
exchangers: structure, function, and evolution of the respiratory processes
about development of respiration and breathing in various creatures living
on Earth in the past and now. He is one of the leading modern authorities on
respiration of different life forms.
Fig. Carbon dioxide and oxygen: Evolution of air on Earth
and body cell O2 and CO2 parameters.
Appearance of the first vertebrates (about 550 millions years ago) and
the development of prototypes of human lungs took place when air was made up
of only about 1% O2, while having much higher percentage of CO2 (Maina,
1998), likely over 7%. Normal air today has many times more O2 (about 20%)
and only a fraction of the CO2 (0.03%). However, our cells now still live in
the air that existed hundred millions years ago: “But the cells of animals
and humans need about 7 % CO2 and only 2% O2 in the surrounding environment.
This is the way how our cells live: cells of the heart, brain, and kidneys”
Hence, most of the time our lungs were developing and evolving in
conditions when the CO2 content was high (up to 7-12% during the first
stages of development), with gradual decline, and low O2 values (about 1% or
less during the first stages of O2 evolution). During these stages the process of control of
breathing by the nervous system was also developed. Since this primitive air
had very little O2, our evolutionary predecessors could get more oxygen in
tissues by breathing more. Since any stressful situation, digestion, search
for food, mating, playing, and any other activity required more oxygen,
hyperventilation became the fundamental reflex or instinct. Only totally
peaceful stress-free rest had low metabolic rate where heavy breathing would
not give any advantage for survival.
On the other hand, however heavy was breathing of these primitive
creatures in the past, they would still get the main nutrient, CO2, from
air. The CO2 content in tissues had to be even higher than in air and these
creatures would never develop spasms of coronary vessels, bronchi, other
smooth muscles, or abnormal excitability of the nerve cells, or muscular
tension or any other above-mentioned negative effects. Hence, nature did
provide primitive creatures with ability to function without all
above-discussed physiological flaws.
However, the main parameter of our environment, our air, had dramatic
change during later stages of our evolution due to advance of green life
that transforms CO2 into O2 during photosynthesis.
We can see that air had dramatic change during evolution. It now has too
much oxygen and almost no CO2. Hence, the chief parameter of our environment
(we can survive for days or weeks with no water or food, but only for
minutes with no air) became abnormal in its composition. It is only
existence of our lungs that protected us from extinction. Nature could not
anticipate this cardinal change in air, but it did provide us with the means
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