Scientists from Iowa State and the University of Colorado have claimed to found new evidence that the ancient Earth was an unbroken area of water, with no continent. Scientists examined ancient samples of seafloor found in Australia and found clues that Earth used to be a completely blue planet. They have revealed when the Earth was around 1.5 billion years old, its ocean was swimming with the isotope oxygen-18. Nowadays, continental landmasses absorb much of the oxygen-18 out of the water. Therefore, the abundance of oxygen-18 in the ancient ocean supports the theory of complete “Blue Planet”. Scientists believe their findings have deep implications and could lead to the reformation of the theory of human evolution on Earth.