However, the rocks in the recent study are thought to date back some 3.95 billion years. What’s more, the carbon found within them was shown to contain a particular blend of isotypes. And with its high concentration of carbon-12, it’s likely that this graphite came from an organic source.
So does this prove that there was life on earth 3.95 billion years ago? If true, this discovery will push back the date of the oldest known organic graphite by some 150 million years. In fact, it suggests that living matter was thriving on the earth just 500 million years after it first formed.