Shark Bay's Hidden Microbial Treasures
In what initially appeared to be a pile of rocks in Shark Bay, researchers from UNSW Sydney have discovered a hidden clue to the origins of complex life on Earth. The scientists identified a previously unknown Asgard microbe, which may provide insights into how plants and animals first evolved. The discovery was made in Shark Bay, a World Heritage-listed site in Western Australia, which continues to hold ancient microbial communities known as stromatolites.
Associate Professor Brendan Burns, an evolutionary microbiologist at UNSW, explains, “Stromatolites could be more than ‘just’ a cradle of life where early microbial life flourished. They could also tell us how complex life first emerged.” These stromatolites are dense, layered communities of microbes that have existed for billions of years and played a crucial role in oxygenating Earth’s atmosphere before complex life forms appeared.
The study, published today, was conducted in collaboration with researchers from the University of Technology Sydney and The University of Melbourne. It identified the microbe living in partnership with another organism, offering the first visual evidence of its interactions through tube-like structures called nanotubes. The work could help solve one of biology’s biggest mysteries: how simple cells first combined to form more complex life.
The Microbial Village
Stromatolites, found to host the Asgard archaea, are more than just ancient microbial structures. In the study, researchers isolated a member of the Asgard archaea, a unique group of microbes thought to be closely related to the ancestors of eukaryotes. This group includes the cells that make up all plants and animals, including humans. The Asgard archaea, specifically the microbe named Nerearchaeum marumarumayae, were discovered using advanced techniques like electron cryotomography. This technology allowed scientists to visualize the physical interactions between the archaea and bacteria.
A long-standing theory suggests that the first eukaryote arose when an ancient archaeon and a bacterium formed a symbiotic relationship, eventually leading to the formation of mitochondria, the powerhouse of cells. “This could be a little model for how these kinds of partnerships started and formed eukaryotes,” says A/Prof. Burns.
While genetic sequencing revealed the organisms’ DNA within the samples, cultivating these microbes outside their natural environment proved challenging. “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.
The researchers plan to continue their studies in Shark Bay, hoping to uncover more about these ancient microbial interactions and their evolutionary significance. Further research aims to explore more microbial partnerships and their implications for understanding early complex life evolution. This ongoing work is crucial for unveiling the mysteries of life’s origins on Earth.
Last updated: 10 April 2026, 5:49 pm
