Between a Pod and a Hard Test: The Deep Evolution of Amoebae

Area of Science:

• Eukaryotic evolution
• Microbial genomics
• Phylogenetics

Background:

• Amoebozoa, sister to animals and fungi, is diverse yet understudied.
• These organisms play crucial roles in nutrient cycling across diverse environments.
• Understanding Amoebozoa's evolutionary history is vital for comprehending eukaryotic diversity.

Purpose of the Study:

• To construct a robust phylogeny of Amoebozoa using phylogenomic methods.
• To resolve major clades and evolutionary patterns within Amoebozoa.
• To infer ancestral traits of the Amoebozoa lineage.

Main Methods:

• Phylogenomic analysis of 325 genes.
• Transcriptomic data from 61 diverse taxa (culture-based and single-cell).
• Comparative analysis to reconstruct ancestral life cycle characteristics.

Main Results:

• Identified two major clades: Discosea and Tevosa, refuting some previous studies.
• Phylogenetic analysis supports a sexual, flagellated common ancestor for Amoebozoa.
• Evidence suggests ancestral ability to form sporocarp-type fruiting bodies.

Conclusions:

• Macroevolutionary patterns in Amoebozoa are shaped by parallel losses of ancestral traits (flagella, sex, sporocarps).
• The study refutes convergent evolution as the primary driver of observed diversity.
• Provides a new framework for understanding Amoebozoa evolution and diversity.