Whenever a nerve cell is stimulated, it emits a signal that will always cause the same sensation. Nerve cells are part of the nervous tissue of some organs and can be divided into two types: neurons and glial cells.
What you need to know about these cells, to consider the theory shown above to be true, is that nerve cells obey the "all or nothing" law, that is, no matter the intensity of the stimulus, if they are stimulated, the as little as possible, will always cause the same sensation.
That the Homo Sapiens originated in Africa and spread throughout the whole world over millions of years and that (if I'm not mistaken), they breeded with Neanderthals
