About the word "Can" and "Eş" in Turkish and ideas about their etymological evolution

Turkish is a part of the Altaic language group which sometimes also related to the bigger Uralic-Altaic group.

Altaic group consists of ,

Turkish (with the dialects of Turkiye, Kırgız, Uygur, Azerbaycan, Kazak, Turkmen, Tatar, Ozbek etc.)
Mongolian
Tunguz
Korean
japanese

Of these Turks, Mongolians and Tunguz has the same historic shamanic belief the Tengri religion.
In this shamanic belief every living being or the other things which has living beings on/in them (like a mountain) has a kind of spirit which is called "can" ("tin" in old Turkic) , this "can"  is the spirit which makes a body alive. It is believed that the "can" of every living being is the same type and they are here on Earth as different representations in different bodies. In this concept a mountain or a lake are also living beings those have "cans".

A human has the same type of "can" of a tree or of an animal. When someone is death it is also defined as "canı çıktı" meaning it's (he, she, it, male or female no difference) "can" is went out, so "can" is something which may go in or out from bodies of living beings.

In modern Turkish people who loves each other call each as "can", here the call is to the spirit of that person not the physical body. This call can be referred to an animal as well...

The habits of protecting the nature in modern Turkish culture is also rooted from the "can" concept. In the collective unconscious of the people there is a consciousness about the equality of "cans". This can be seen as idioms mentioning to protect the "cans" or the equality of "cans" or the spiritual connection of the "cans"  in everyday language of Turkish like:

"can suyu": the very first water given to a seed or a small tree when it's planted
" canı çıkmak" the going out of "can", death
"onun canı var" it (he,she,it) has a can (used to emphasize the situations which it's representation on earth, the body that carries the "can" needs to be protected)

Possibly because of this equality of "cans" there has been no gender in Altaic languages (as well as Uralic ones) as "cans" has no gender.

About the word "eş" in Turkish.

The primary meaning of "eş" is wife or husband, spouse. It is an interesting word again.
Can be used for game mates, members of animal couples etc.

It shows the equality and very close friendship of two. The representation of this friendship is as close as the embryo and placenta. (Placenta is also called as "eş" in Turkish, it is the very close friend of the baby in womb).

A very noticeable etymological feature related to "eş" is the word "eşit ". "Eşit" is evolved from "eş" literally meaning equal.

So equality in Turkic languages are based on the analogy of two "cans" who are very close friends to each. That's why there is no wife of husband but "eş".
Saying;
 "my wife" in Turkish is "Eşim"
"my husband" is "Eşim"
in both cases literally meaning my equal or my very close friend (which feeds me like placenta.)