Asgard archaeon discovery in Shark Bay reveals origins of complex life

Researchers have discovered a previously unknown microbe in Shark Bay, Western Australia, providing the first direct visual evidence of an ancient microbial partnership that may explain the origins of complex life. The study, published in Current Biology, identifies a new Asgard archaeon named Nerearchaeum marumarumayae.

Using electron cryotomography, a high-resolution 3D imaging method, the team captured images of the archaeon physically connected to a bacterium, Stromatodesulfovibrio nilemahensis, via thin, tube-like structures called nanotubes. This physical connection allowed the two organisms to complement each other chemically, exchanging essential compounds such as vitamins, nutrients, and hydrogen.

The discovery supports a long-standing evolutionary hypothesis that the first eukaryotic cells—the complex cells that make up all plants, animals, and humans—emerged from an intimate partnership between an ancient archaeon and a bacterium. The samples were obtained from subsurface layers of ancient microbial mats in the World Heritage-listed Hamelin Pool, a site that offers a living system resembling conditions on early Earth.