Practice question

Phylogenomic reconstructions using concatenated informational genes and recently discovered Asgard superphylum archaeal lineages like Lokiarchaeota, Thorarchaeota, and Heimdallarchaeota demonstrate that Eukarya branches within Archaea making Archaea paraphyletic. Asgard genomes encode eukaryotic signature proteins such as ESCRT complex, ubiquitin system, actin, and tubulin homologs absent in other bacteria. Informational machinery including ribosomal proteins and RNA polymerase subunits closely resembles eukaryotic versions. Therefore Archaea, not Bacteria, represent closest prokaryotic relatives of eukaryotes, supporting two-domain tree where eukaryotes emerged from archaeal ancestor through endosymbiosis and genome expansion.