Asgard Archaea May Reveal How Complex Life Began
Author: University of New South Wales
Published: 2026/04/09
Publication Details: Peer-Reviewed, Anthropology News
Category Topic: Anthropology - Related Publications
Contents: Synopsis - Introduction - Main - Insights, Updates
Synopsis: This research, published in the peer-reviewed journal Current Biology, presents the first direct visual evidence of an Asgard archaeon physically connecting with a bacterium through nanotube structures found in the ancient stromatolite mats of Shark Bay, Western Australia - a finding that sheds light on one of biology's most profound open questions: how simple cells gave rise to the complex life that includes every plant, animal, and human being on Earth. The study is led by researchers from UNSW Sydney, the University of Technology Sydney, and the University of Melbourne, bringing together evolutionary microbiology, electron cryotomography, and machine learning-based protein structure prediction. For anyone interested in the origins of life, human evolution, or the role of microbial ecosystems in shaping our planet, this work offers a rare and tangible glimpse into events that unfolded billions of years ago - and may still be unfolding today - Disabled World (DW).
- Topic Definition: Asgard Archaea
Asgard archaea are a group of single-celled microorganisms belonging to the domain Archaea, first identified through environmental DNA sequencing and considered the closest known microbial relatives to eukaryotes - the cells that make up all complex life, including animals, plants, and fungi. Named after realms in Norse mythology, Asgard archaea are typically found in deep-sea sediments and other extreme environments, and their unique genetic and structural features have led scientists to propose that eukaryotic cells may have evolved directly from an ancestral Asgard archaeon that entered into a symbiotic relationship with a bacterium. Because they are extraordinarily difficult to culture in a laboratory setting, direct physical observation of Asgard archaea has been rare, making any new structural or behavioral evidence of how they interact with other organisms an important contribution to understanding the origins of complex life on Earth.
Introduction
From Asgard to Earth - Tiny Discoveries Hold Clues to Life's Greatest Leap
Stromatolites - and their close relatives, microbial mats - could be mistaken for what seems like a bunch of old dark rocks. But instead, they are dense, layered communities of microbes. Long before complex life such as animals or plants existed, stromatolites breathed the first molecules of oxygen into Earth's atmosphere. Now, in a study published today, researchers say they may also hold insights into how complex life began.
Main Content
An Asgard Archaeon From a Modern Analogue of Ancient Microbial Mats
Associate Professor Brendan Burns, an evolutionary microbiologist at UNSW Sydney, is part of a team that identified a previously unknown microbe living in close partnership with another organism inside these 'living fossils'. The work, co-led with researchers from the University of Technology Sydney and the University of Melbourne, could help solve one of life's biggest mysteries: how simple cells first combined to form more complex life.
"Stromatolites could be more than 'just' a cradle of life where early microbial life flourished," says A/Prof. Burns. "They could also tell us how complex life first emerged."
The 'Microbial Village that Helped Raise a Eukaryote'
Though they were first on Earth billions of years ago, stromatolites and mats continue to form in Shark Bay, which is a World Heritage-listed site in Western Australia. It was here that A/Prof. Burns and colleagues collected samples and eventually isolated a member of the Asgard archaea - a group of unique microbes thought to be closely related to the ancestors of eukaryotes, which are the cells that make up all plants and animals, including humans.
A long-standing theory in biology suggests the first eukaryote arose when an ancient archaeon and a bacterium formed a close partnership, with one eventually engulfing the other. This union gave rise to mitochondria - the powerhouse of cells. But what scientists have been missing is direct evidence of how such relationships might have looked in practice.
This study provides the first visual evidence of an Asgard archaeon physically interacting with a bacterium through fine, tube-like structures known as nanotubes.
"This could be a little model for how these kinds of partnerships started and ultimately formed eukaryotes," says A/Prof. Burns.
The Long Road of Discovery
While genetic sequencing revealed the organisms' DNA lurking within the samples, cultivating the microbes to observe them in action was difficult.
"It took four or five years in the lab," A/Prof. Burns says. "A lot of time, optimising and chasing different shadows."
Asgard archaea are notoriously difficult to cultivate outside their natural environment, so the team was unable to grow them in isolation. A/Prof. Burns says this is a finding that could also be significant.
"The fact that we could never get these organisms into pure culture is probably because they always depend on other organisms to survive," he says.
The breakthrough came with electron cryotomography, a high-resolution 3D imaging technique that allowed researchers to see structures at the scale of a millionth of a millimetre. The images revealed the two organisms physically linked by bacterial nanotubes. The archaeon also appeared to sprout chains of budded vesicles and elaborate tube-like structures. Each microbe made compounds that the other could use, including vitamins, nutrients and hydrogen.
Coauthor Associate Professor Debnath Ghosal from the University of Melbourne says capturing the first direct physical interaction between an Asgard archaeon and a bacterium is especially exciting.
"This discovery brings us a few steps closer towards understanding how complex cells evolved from relatively simpler microbial life forms," A/Prof. Ghosal says.
Coauthor Associate Professor Kate Mitchie from UNSW says the research included an element of deep learning - a type of machine learning.
"We used this to predict the structures of proteins in these microbes," A/Prof. Mitchie says. "And that's exciting because we can start to see ancient versions of the cellular machinery that later became central to complex life."
A/Prof. Burns likens archaea to 'companions'. Under the harsh conditions that batter microbial mats, this kind of cooperation, even at the microscale, could be vital for survival.
An Ancient but Living Story
Coauthor Associate Professor Iain Duggin from the University of Technology Sydney says it's amazing to imagine that these microbes could have been in partnership in these environments for millions of years, giving rise to complex life - including humans.
"It's as if we have slowly arisen from the bottom of the sea," A/Prof. Duggin says.
The newly identified archaeon was named Nerearchaeum marumarumayae after the ancient Greek sea god Nereus and the Malgana word marumarumayae, meaning 'ancient home'. Malgana is one of the traditional languages of the people of central Shark Bay, whose ties to country are recognised by Native Title. Malgana elders, rangers and community actively work in Shark Bay caring for country, protecting wildlife and restoring the land.
Shark Bay has a rich Indigenous history, with Indigenous people first inhabiting the area around 30,000 years ago. The naming process involved consultation with Kymberly Oakley, the world's foremost Malgana language expert. Malgana elders were also consulted for appropriate words that could be respectfully used in the naming of the new microbe. The elders granted permission to incorporate language that allowed the Malgana culture to be recognised and celebrated.
For scientists, these microbial communities offer a rare window into early Earth. For Traditional Owners, they are part of a cultural heritage that continues to be cared for and protected.
A/Prof. Burns hopes to uncover more microbial partnerships, expanding what he calls a "little primordial Asgard soup", to help scientists piece together the earliest chapters of complex life.
"But it's not just about the organisms," he says. "It's about people as well. A huge collaborative effort across disciplines with many graduate students being instrumental in building this story."
"Part of what makes this exciting is that it's not just discovery, but connection. Not just across many years, but at a time when these fragile ecosystems face mounting threats from climate change and human activity."
The microbes show how life depended on cooperation to survive - which A/Prof. Burns says is just as essential today.
"These microbes remind us that even the smallest partners can leave the deepest mark on our history."
Insights, Analysis, and Developments
Editorial Note: What makes this study stand out is not just the science - it is the way the research itself mirrors the very story it is telling. Just as the first eukaryote likely arose from an unlikely partnership between two microscopic organisms, this work was built on collaboration: across universities, across disciplines, and across cultures. The decision to name the newly identified archaeon using the Malgana language of the Traditional Owners of Shark Bay, following proper consultation with community elders and language experts, gives this discovery a dimension that goes well beyond the laboratory. These living mats have sat at the edge of Shark Bay for millennia, tended by people whose connection to that country predates recorded science by tens of thousands of years. That the science now honours that relationship is, in its own quiet way, as significant as the discovery itself - Disabled World (DW).Attribution/Source(s): This peer reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by University of New South Wales and published on 2026/04/09, this content may have been edited for style, clarity, or brevity.