The infochemical core

TL;DR

This study investigates the distribution of infochemicals across species, revealing a double Zipf distribution that suggests a shared chemical core similar to core vocabularies in human language.

Contribution

It introduces a novel analysis of infochemical distribution across species and identifies a double Zipf pattern, indicating a shared chemical core among diverse organisms.

Findings

Double Zipf distribution best fits infochemical data

Shared chemical core exists across species

Chemical repertoire resembles core vocabularies in language

Abstract

Vocalizations and less often gestures have been the object of linguistic research over decades. However, the development of a general theory of communication with human language as a particular case requires a clear understanding of the organization of communication through other means. Infochemicals are chemical compounds that carry information and are employed by small organisms that cannot emit acoustic signals of optimal frequency to achieve successful communication. Here the distribution of infochemicals across species is investigated when they are ranked by their degree or the number of species with which it is associated (because they produce or they are sensitive to it). The quality of the fit of different functions to the dependency between degree and rank is evaluated with a penalty for the number of parameters of the function. Surprisingly, a double Zipf (a Zipf distribution with two regimes with a different exponent each) is the model yielding the best fit although it is the function with the largest number of parameters. This suggests that the world wide repertoire of infochemicals contains a chemical nucleus shared by many species and reminiscent of the core vocabularies found for human language in dictionaries or large corpora.