The first pressing evidence that humans might not have been the first complex life form to appear on the planet has been introduced. This is just one of a series of controversial studies pointing to the fact that complex life forms might have existed on our planet at a time when scientists believed no life was present.
Scientists universally agree that Earth is around 4.6 billion years old, but the topic of life on the planet is a more controversial one. Now, scientists have discovered carbon-laced crystals which are up to 300 million years older than the ‘oldest life on Earth.’”
The crystals are not proof of the existence of biological life, but they do indicate the presence of chemical signs of life.
Furthermore, a team of geochemists at the University of California at Los Angeles have found evidence that there was life on Earth 4,100 million years ago.
“Twenty years ago, this would have been heretical; finding evidence of life 3.8 billion years ago was shocking,” said Mark Harrison, co-author of the research and a professor of geochemistry at UCLA.
A separate study published in the Proceedings of the National Academy of Sciences analyzed isotopic ratios of selenium in sedimentary rocks to measure the presence of oxygen in the Earth’s atmosphere between 2 and 2.4 million years ago.
“This research shows that there was enough oxygen in the environment to have allowed complex cells to have evolved, and to have become ecologically important before there was fossil evidence,” Roger Buick, lead author, writes. “That doesn’t mean that they did — but they could have.”