Each time scientists announce a new discovery on the origins of life, they have to do so with a grain of salt because a future finding may expand on what we think we know about our planet’s early history. This time, it’s the age of ancient crystals found near Perth, Australia, that have researchers questioning earlier held assessments of the beginnings of life on Earth.
It’s accepted that the multi-billion-year-old zircon crystals found at Jack Hills, about 600 kilometers (373 miles) northeast of Perth, are the oldest known material ever found on dry land. Scientists from Stanford University and the University of California examined rocks from the area close to where the crystals were harvested, and they believe they have found one that contains “the signature of life.” That signature comes in the form of a carbon deposit, which researchers now believe could be about 4.1 billion years old. Scientists say this means life could have begun on Earth about 300 million years earlier than previously thought.
That’s the conclusion from the international research team, but locals are skeptical. Australia’s Curtin University School of Mines associate professor Alexander Nemchin doesn’t think the ‘signature’ necessarily equates to proof of early life. “It is significant because it states the possibility, but whether it gives us 100 per cent confidence … probably not,” he said.
Essentially, Nemchin thinks it’s premature to see carbon and immediately jump to the conclusion that it’s evidence of living organisms. That said, he isn’t dismissing the work of the California scientists entirely. He told ABC they probably did the best they could to apply current methods of analysis and understanding. He also admitted that the carbon found in the crystal “probably” does mean life on Earth began earlier than previously thought. “To some extent it confirms the idea that life probably existed very early, almost from the beginning of the planet itself and the solar system itself and probably not really restricted to our planet,” he said.
Images via John W. Valley/University of Wisconsin