The unstable evolutionary position of Korarchaeota and its relationship with other TACK and Asgard archaea.

The applications of marker gene concatenation have been advanced to resolve the key questions in the Tree of Life. However, the interphylum evolutionary relationship between Korarchaeota of TACK ( Thaumarchaeota , Aigarchaeota , Crenarchaeota , Korarchaeota ) and Asgard archaea remains uncertain. We applied a marker gene ranking procedure to examine their evolutionary history. Our updated trees showed confident placements of (1) Korarchaeota as the basal branch to other TACK archaea and as a sister group to Asgard archaea; (2) Njordarchaeota at basal branch to Korarchaeota instead of within Asgard archaea. They highlight the importance of evaluating marker genes for phylogeny inference of the Archaea domain.