"I'm not against the idea that there were higher nutrients 2.1 billion years ago but I'm not convinced that this could lead to diversification to form complex life," he said, suggesting more ...

For example, zircons are simple silicate crystals that date back to the time before life started. A zircon found in Australia ...

It's among the earliest examples of continuous ... "They show that a type of complex behaviour had evolved before the Cambrian (when multi-cellular life exploded into a wide variety of forms ...

Most experts believe that the complex life on Earth began around 635 million years ago. However, a new theory is challenging that. Researchers, including Professor Ernest Chi Fru at Cardiff ...

Complex life on Earth may be older than previously thought. New findings suggest that conditions for life existed 1.5 billion years earlier than it was originally considered to have begun.

That means organisms with a complex chemical system that ... nitrogen dioxide in the atmosphere. These are examples of tracers of intelligent life called technosignatures. It's unclear how and ...