Scientists Capture First Images of Ancient Cell Partnership That May Explain How Complex Life Began

A Living Snapshot of Life's Greatest Leap

Scientists have achieved a landmark breakthrough in evolutionary biology by capturing the first direct images of an Asgard archaeon physically connected to a bacterium, offering an unprecedented glimpse into the type of ancient partnership that may have given rise to all complex life on Earth.

The study, published on 9 April 2026 in Current Biology, describes a newly identified microbe named Nerearchaeum marumarumayae, isolated from the stromatolites and microbial mats of Shark Bay, a World Heritage-listed site in Western Australia. The research was co-led by Associate Professor Brendan Burns of UNSW Sydney, alongside collaborators at the University of Technology Sydney and the University of Melbourne.

Nanotubes and Nutrient Sharing

Using electron cryotomography, a high-resolution 3D imaging technique capable of resolving structures at the scale of a millionth of a millimetre, the team observed the archaeon and a bacterial partner called Stromatodesulfovibrio linked by fine tube-like structures known as nanotubes. The archaeon also appeared to sprout chains of budded vesicles and elaborate tubular projections.

Biochemical analysis revealed that the two organisms exchanged vitamins, nutrients, and hydrogen gas, each producing compounds the other needed to survive. The team was never able to grow the archaeon in isolation, a detail Burns considers telling of its deep dependence on bacterial partners.

Why It Matters

Asgard archaea are widely considered the closest living relatives of eukaryotes, the domain of life encompassing all animals, plants, and fungi. A leading hypothesis holds that the first eukaryotic cell arose roughly two billion years ago when an ancient archaeon and a bacterium formed a symbiotic partnership so intimate that one engulfed the other, eventually giving rise to mitochondria. What had been missing until now was direct observational evidence of what such a partnership might have looked like in practice.

The organism's name honours both Greek mythology and Indigenous Australian heritage, combining the ancient Greek sea god Nereus with the Malgana word marumarumayae, meaning ancient home, chosen in consultation with Malgana elders.