Since Aristotle, it has been assumed that humans occupy the highest position when living beings are arranged in ascending order of their complexity and perfection. This is the so-called scala naturae, which, however, only holds true if the ranking is based on the complexity of the nervous system. With regard to other organs and systems, this order cannot be maintained. For example, if one takes the sensitivity of the olfactory system as a criterion, then “… modern humans seem to be a degenerate animal for whom the language of scents has long since lost its original profound significance” (according to the French scientist M. Barbier). And yet, there is ample evidence that, while chemical signals are not vital for modern humans, they were essential for primitive humans. According to some experts, the chemical mode of communication in Homo sapiens is still not without significance today.