Asgard microbes may reveal how complex life began

A Nature study reports hundreds of previously unknown Asgard genomes from deep-sea vents and shallow coastal sediments, and finds some lineages carry genes linked to oxygen metabolism, suggesting parts of the group could tolerate or use oxygen.

Scientists report new genomic evidence that expands the known diversity of Asgard archaea and links some lineages to oxygen use. The team assembled hundreds of genomes from deep-sea hydrothermal vents and shallow coastal sediments. They compared protein families and used an AI model to predict protein folding and potential function. The work is discussed in the context of how eukaryotes first appeared after the Great Oxidation Event. Key findings: - The study assembled hundreds of previously unknown Asgard genomes from both deep and shallow marine sites. - Several Heimdall-related proteins resemble eukaryotic proteins involved in processing oxygen and generating energy. - Some Asgard lineages were identified in shallow coastal sediments and show genetic signs of oxygen tolerance or use. - The team used large-scale DNA sequencing and AI-based protein structure predictions to infer likely metabolic capabilities. - The authors and outside experts note that genetic predictions need biological confirmation because modern Asgards have likely changed since ancient times. Summary: The findings add evidence that some Asgard archaea may have been present in oxygenated coastal environments and possessed molecular features linked to oxygen metabolism. Researchers say further laboratory tests and environmental oxygen measurements are needed, and some authors express hope that future work could observe aspects of eukaryogenesis in controlled settings.