Does Phylogenetic Proximity Explain Nestedness in Mutualistic Ecosystems?

TL;DR

This study examines whether phylogenetic proximity influences the nested contact patterns in mutualistic ecosystems, concluding that nestedness arises mainly from a general contact rule rather than phylogenetic proximity.

Contribution

The paper introduces a dynamical model and a parameter to assess the role of phylogenetic proximity in nestedness, showing it is not the primary cause.

Findings

Nestedness is compatible with phylogenetic proximity but not caused by it.

Species tend to contact highly connected counterparts, leading to nested patterns.

Maximizing phylogenetic diversity aligns with the general contact rule.

Abstract

We investigate how the pattern of contacts between species in mutualistic ecosystems is affected by the phylogenetic proximity between the species of each guild. We develop a dynamical model geared to establish the role of such proximity in the emergence of a nested pattern of contacts. We also define a parameter that provides a direct measure of the influence of phylogenetic proximity in a given pattern of contacts. We conclude that although phylogenetic proximity is compatible with nestedness it can not be claimed to be a cause of it. We find that nestedness can instead be attributed to a general rule by which species tend to hold contacts with counterparts that already have a large number of contacts. If the phylogenetic structure of both guilds is brought into the analysis, this rule is equivalent to maximize the phylogenetic diversity of the mutualistic counterparts of species of either guild.