Oxygen-Tolerant Archaea Rewrite Complex Life Origin

Scientists at the University of Texas at Austin, led by Brett Baker, have published research in the journal Nature providing evidence that Asgard archaea, close relatives of the ancestors of complex life (eukaryotes), can tolerate or even use oxygen. This challenges the long-held belief that these microbes thrived only in oxygen-free environments and resolves a puzzle in the theory of how complex life evolved. The discovery suggests that complex life likely evolved in an environment where oxygen was present, aligning with the Great Oxidation Event. The research involved extensive genome sequencing, assembling over 13,000 new microbial genomes, and using AI (AlphaFold2) to predict protein structures, revealing that Heimdallarchaeia proteins resemble those used by eukaryotic cells for oxygen-based metabolism. This work was funded by several foundations and government agencies.