Close Encounters of the Third Domain: The Emerging Genomic View of Archaeal Diversity and Evolution
Figure 2
Overview of theories regarding the origin of the eukaryotic nuclear lineage. (a) The classical, Woesean three domains of life tree in which the nuclear lineage vertically evolved from the archaea-eukaryote common ancestor. (b) The fusion tree in which the nuclear lineage originated from the archaeal partner in the fusion. Depending on which fusion model, the archaeal parent’s lineage () was either part of the euryarchaeota [SET [93], original syntrophy hypothesis [94], hydrogen hypothesis [95] or alternative syntrophy hypothesis [51]], the Crenarchaeota (eocyte hypothesis) [96], or the TACK superphylum (PhAT) [58]. “” represents all archaea not directly affiliated with “.” (c) The neomuran tree in which the eukaryotic and archaeal lineage (combined referred to as “neomurans”), evolved vertically from ancestor shared with actinobacteria () as a result of the loss of bacterial-type cell wall (the neomuran revolution). represents all bacteria not directly affiliated with . (d) The eukaryote-early tree, which suggests that the last common universal ancestor was more eukaryote-like than prokaryote-like.
