A weaker magnetic field may have paved the way for marine life to go big
Earth’s magnetic field protects life from harmful cosmic radiation. But sometime between about 590 million and 565 million years ago, that security blanket seems to have been much thinner — with far-reaching effects for the development of life on Earth, researchers suggest.
A weaker magnetic field could account for the higher levels of oxygen recorded in the Earth’s atmosphere and oceans around that time — and for the ensuing proliferation of macroscopic marine animals, the team reports in the May 2 Communications Earth & Environment. More