The last several articles in this series considered how the body distributes and controls its water content.
When it comes to controlling the body’s water content, life is a bit more complicated than evolutionary biologists would have us believe.
Evolutionary biology must explain how life actually works, not just how it looks.
In dealing with the laws of nature, our body is constantly losing water, mainly through respiration, perspiration, and the formation of urine.
The force that opposes filtering water out of the circulation by the hydrostatic pressure is osmosis.
Water is the body’s most abundant molecule, making up about 60 percent by weight.
It’s the iron (Fe) in the hemoglobin molecule to which O2 actually attaches and enables it to be transported in the blood.
When a person’s level of hemoglobin drops below the normal range, the result is anemia.
How well has evolutionary biology explained the gradual development of the respiratory system?
For our ancient ancestors, being able to bring this much O2 into the body would have been the difference between eating or being eaten.