Unikonts

Unikonts is a major clade within eukaryotes defined primarily by molecular phylogenetic analyses. In traditional two-supergroup schemes, unikonts include the Amoebozoa and the Opisthokonta, the latter group containing animals, fungi, and their unicellular relatives. In many modern classifications, the same assembly is referred to as Amorphea, a name used to emphasize the close relationship between Amoebozoa and Opisthokonta. The explicit membership of unikonts can be somewhat unsettled, and some small lineages such as Apusomonadida and Ancyromonadida have been variably placed inside or near the group depending on the data.

Morphological features associated with unikonts do not provide a single, unambiguous diagnostic trait. The clade is supported largely by molecular phylogeny, and while there is a tendency for a single emergent flagellum in many basal or related forms, several opisthokonts lack flagella in their mature life stages. As a result, the term unikont is primarily a reflection of evolutionary relationships rather than a clear morphological synapomorphy.

Significance and diversity: Unikonts include the vast majority of multicellular eukaryotes and several major model lineages. Opisthokonta comprises animals, fungi, and their unicellular relatives, while Amoebozoa contains many amoeboid and slime mold lineages. The study of unikonts informs understanding of early eukaryote evolution, cell biology, and the origins of animals and fungi. In contemporary usage, the term has sometimes been supplanted by Amorphea or other frameworks, reflecting ongoing debates about deep eukaryotic relationships.