From ScienceDirect:
Life was limited for most of Earth’s history, remaining at a primitive stage and mostly marine until about 0.55 Ga. In the Paleozoic, life eventually exploded and colonized the continental realm. Why had there been such a long period of delayed evolution of life? Early life was dominated by Archaea and Bacteria, which can survive ionizing radiation better than other organisms. The magnetic field preserves the atmosphere, which is the main shield of UV radiation. We explore the hypothesis that the Cambrian explosion of life could have been enabled by the increase of the magnetic field dipole intensity due to the solidification of the inner core, caused by the cooling of the Earth, and the concomitant decrease with time of the high-energy solar flux since the birth of the solar system. Therefore, the two phenomena could be responsible for the growth and thickening of the atmosphere and the development of land surface life. Paper. (public access) – Carlo Doglionia, Johannes Pignattia, Max Coleman More.
Note: “Open Access funded by China University of Geosciences (Beijing) Under a Creative Commons license” This is a welcome development from the perspective of people who pay taxes to fund science we can’t afford to buy.
See also: What sparked the Cambrian explosion? … again A raft of hypotheses. It is beginning to sound somewhat like: Causes of World War One (But that’s a good thing.)
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