Why do the chicks in the egg not die from lack of oxygen?

The maturing embryos of most mammals do not need to breathe in the womb. The placenta enveloping them is permeated with vessels through which liquid rich in oxygen and nutrients is supplied. The mother in this case both breathes and eats for her offspring, and the baby begins to do this himself only after he is born.

The stomata of plants, resembling microscopic mouths, open and begin to breathe, barely being exposed to the sun's rays. Amoebas and other single-celled organisms that reproduce by mitosis are fully formed before they split into two separate living units. And only the eggs remain in no way attached to the parent, which would contribute to the development of an immature creature.

So how do chicks breathe inside the eggs?

Air pocket

It is well known that chicken eggs contain an impressive supply of nutrients. That is why they are considered an indispensable part of any healthy diet. However, they do not have enough oxygen for the development of chicks. However, you should not worry about the life of these birds. Evolution has provided a mechanism that allows the embryo not to feel the need for life-giving gas.

Between the two membranes located under the inside of the shell, there is a small air pocket. The oxygen contained there is intended to supply the developing chick, but the gas reserves for the entire period of incubation are clearly not enough in it. It is consumed in the last days before birth, and the rest of the time, gas exchange is carried out directly through the egg shell.

Breathable shell

It is known that all living organisms consist of six basic chemical elements: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. In the understanding of most terrestrial scientists, life without oxygen does not seem possible at all. If it did not enter the egg, the chick would die inside, unable to hatch into fresh air. But the shell of bird eggs is not airtight. What's more, it's not even waterproof.

In the calcium-rich structure of the eggshell and in the shell membrane, there are tiny holes through which carbon dioxide escapes and oxygen enters. Thus, the shell itself performs the function of the lungs, providing a full-fledged gas exchange until the chick is born. Nice, isn't it?

Birds are not the only living creatures on our planet that use their eggshells in this way. The same thing happens, for example, in reptiles. In general, we are dealing with another brilliant discovery of evolution, which works excellently, despite the seeming paradox.