Mysterious life forms discovered in ancient lava caves of Hawaii

A researcher in a Hawaiian cave passage (Image credit: Kenneth Ingham)

New research has uncovered thousands of previously-unknown bacterial species in the ancient lava caves of Hawaii. Authors of the study published last week in Frontiers in Microbiology theorised that research into these microbial ecosystems could help us understand how life can survive in extreme conditions like those on Mars.

The volcanic processes that created the islands of Hawaii also led to the formation of underground tunnels and caves that are extremely dark, cold and full of toxic gases. Although such conditions are unsuitable for most life forms as we know them, scientists have now discovered “unexpectedly high levels of bacterial diversity” in these lava caves.

These geothermal vents and lava caves date back between 600 to 800 years, and they are similar to the conditions that once existed on Mars, which had active volcanoes and fumaroles.

“Hawaiian volcanic environments can provide some insight into the possibility of life on Mars in its ancient past and how microbial communities could survive today on Mars in lava caves,” the study theorised.

Very little is known about the mysterious bacterial species discovered in these ancient Hawaiian caves as of now, although scientists were surprised to find a class of bacteria known as Chloroflexi there.

Chloroflexi is a “hub” species, which means they play a key ecological role in the community, according to The Express.

“This study points to the possibility that more ancient lineages of bacteria, like the phylum Chloroflexi, may have important ecological ‘jobs,’ or roles,” said first author Dr Rebecca D Prescott of NASA Johnson Space Center and University of Hawaiʻi .

“The Chloroflexi are an extremely diverse group of bacteria, with lots of different roles found in lots of different environments, but they are not well studied and so we don’t know what they do in these communities.

“Some scientists call such groups ‘microbial dark matter’ – the unseen or un-studied microorganisms in nature.”