The Guardian is reporting that Earth’s earliest life form has been found in Australia. An Aussie research team accompanied by some U.S. scientists discovered a series of “complex microbial ecosystems” they date to 3.5 billion years ago.
The find was made in Australia’s western Pilbara region in rock sediments considered to be some of the oldest found. In a rock body called the Dresser formation, the scientists found entire microbe communities. Slivers of ancient rock were sampled in order to search for the microscopic life.
Team leader and professor David Walcey of the University of Western Australia told the Guardian that the radical find “pushes back evidence of life on Earth by a few more million years.” The simpler organisms (bacterium and archaea) ruled for millions of years before evolutionary leaps led to more complex, multi-celled lifeforms.
He added, “The Pilbara has some of the best, least deformed rocks on Earth; there aren’t many rocks older than there… I would say this is the most robust evidence of the oldest life on Earth. My team has found evidence dated at 3.45bn years in the past, so we have gone further back by a few million years.”
Walcey’s work is slowly painting a looking-glass view into lifeforms that existed eons before the evolution of man. “Microbes and bacteria like to live in communities. Think about the bacteria in your stomach, for example. These microbes lived in layers that required different chemical gradients to survive. So bacteria that liked light would be towards the top while those that didn’t were towards the bottom.”
Earth was so radically different in almost every way, from higher temperatures to even higher sea levels. Bacteria like those the team discovered would have been the predominant form of life for several billion years.
“Bacteria ruled the world back then [and] it would’ve been a very smelly world indeed,” Walcey observed. “It would’ve been pretty hostile for us. There was essentially no oxygen, a lot of CO2 and methane and much warmer oceans.”
The ramifications of the discovery could impact how we view the entire solar system. “These kinds of ecosystems could be viewed by a rover, such as the one that visited Mars,” Walcey said. “We wouldn’t know the age, of course, as we couldn’t date them. But we would know that there was life at some point on another planet, which would be pretty exciting.”
If you’re interested in the elementary basics of life on Earth, here’s a BBC2 clip describing the evolution of the first microorganisms on our planet:[Image via this BBC2 clip on YouTube]