Phylogeny, character evolution, and classification of Sapotaceae (Ericales)

Area of Science:

• Botany
• Evolutionary Biology
• Phylogenetics

Background:

• The Sapotaceae family, predominantly tropical, lacks a robust phylogenetic classification.
• Previous classifications have been challenged by new data, necessitating a re-evaluation of evolutionary relationships.

Purpose of the Study:

• To conduct the first cladistic study of Sapotaceae using both morphological and molecular data.
• To resolve evolutionary lineages, assess tribal and generic monophyly, and propose an updated classification.

Main Methods:

• Utilized standard parsimony and parsimony jackknife algorithms.
• Analyzed equally and successively weighted morphological and molecular characters.
• Performed cladistic analyses to infer phylogenetic relationships.

Main Results:

• Confirmed two primary evolutionary lineages within Sapotaceae: Isonandreae-Mimusopeae-Sideroxyleae and Chrysophylleae-Omphalocarpeae.
• Sideroxyleae is monophyletic; Isonandreae and Chrysophylleae require redefinition, with Chrysophylleae being monophyletic only when including Omphalocarpeae.
• Proposed revisions to generic limits within Sideroxyleae (Argania, Nesoluma, Sideroxylon) and highlighted issues with Chrysophyllum and Pouteria monophyly.

Conclusions:

• The study proposes an amended subfamily classification: Sarcospermatoideae, Sapotoideae, and Chrysophylloideae.
• Morphological characters often exhibit homoplasy, complicating unambiguous phylogenetic signal identification.
• Revised generic and tribal circumscriptions are necessary for a more accurate representation of Sapotaceae evolution.