Origin of life
The earliest evidence of life comes from the Isua supercrustal belt in Western Greenland, and from similar formations in the nearby Akilia Islands. This is because a high level of the lighter isotope of carbon is found there. Living things take up lighter isotopes because this takes less energy. Carbon entering into rock formations has a concentration of elemental δ13C of about −5.5. of 12C, biomass has a δ13C of between −20 and −30. These isotopic fingerprints are preserved in the rocks. With this evidence, Mojzis suggested that life existed on the planet already by 3.85 billion years ago. Against that view is the evidence that our Solar System is very unusual in several respects. For example, it is clear that most star systems have their largest planet close to their star.