Related Experiment Video
Updated: Aug 24, 2026

Modeling the Size Spectrum for Macroinvertebrates and Fishes in Stream Ecosystems
Published on: July 30, 2019
Widespread occurrence of the inverse square distribution in social sciences and taxonomy
Guido Caldarelli1, Cécile Caretta Cartozo, Paolo De los Rios
1INFM, UdR ROMA 1, Dipartimento di Fisica, Università di Roma La Sapienza, Piazzale Aldo Moro 2, 00185 Rome, Italy.
Abstract:
The widespread occurrence of an inverse square relation in the hierarchical distribution of subcommunities within communities (or subspecies within species) has been recently invoked as a signature of hierarchical self-organization within social and ecological systems. Here we show that, whether such systems are self-organized or not, this behavior is the consequence of the treelike classification method. Different treelike classifications (both of real and truly random systems) display a similar statistical behavior when considering the sizes of their sub-branches.
Related Concept Videos
Distribution and Dispersion
Probability Distributions
A discrete probability distribution is a probability distribution of discrete random variables. It can be categorized into binomial probability distribution and Poisson probability...
Normal Distribution
Data: Types and Distribution
Distributions in...
Distributions to Estimate Population Parameter
Central Limit Theorem
The sample size, n, that...

