Secondary Sympatry as a Sorting Process.

Area of Science:

• Ecology
• Evolutionary Biology
• Speciation

Background:

• Elevated trait disparity is observed in sympatric versus allopatric populations.
• Character displacement, driven by costly interactions, was an early explanation for this pattern.

Purpose of the Study:

• To explore the hypothesis of 'species sorting' as a driver of trait disparity and sympatry.
• To define ecological and reproductive species sorting and integrate related concepts like differential fusion and the Templeton effect.
• To distinguish trait differences promoting sympatry from those hindering it and discuss biogeographic impacts.

Main Methods:

• Defining species sorting analogous to character displacement.
• Applying coexistence and community assembly theories.
• Synthesizing existing concepts within the species sorting framework.

Main Results:

• Species sorting posits that lineages require pre-evolved trait differences in allopatry to establish sympatry.
• Distinguishes trait differences that facilitate versus inhibit sympatry.
• Identifies new empirical methods to differentiate species sorting from character displacement.

Conclusions:

• Species sorting is a significant, yet under-discussed, factor in speciation and secondary sympatry.
• Understanding species sorting is key to explaining major biodiversity patterns.
• Further research is needed to elucidate the role of species sorting in generating biodiversity.