Scientists just proved that life on Earth stretches back at least 3.5 billion years

Determining how far back in Earth's history life took root has been an immense challenge for scientists over the years. Finding fossils dating back tens of millions of years can be difficult, but when the timeline stretches to several billion years? Well, let's just say it's exponentially harder. Now, researchers from the University of New South Wales in Australia have discovered what appears to be indisputable evidence of microbial life dating back a whopping 3.5 billion years. The tiny ancient...