Changes in the Geomagnetic Field and the Evolution of Marine Biota

Resumo

Ideas about the geomagnetic field’s influence on evolution and biodiversity are controversial. The quantitative distribution of datum levels of oceanic microplankton during the last 2.0 Ma shows a correlation with geomagnetic reversals. A decrease in field intensity increases cosmic irradiation of the Earth’s surface, which can activate mutagenesis leading to the emergence of new species. Moreover, since the correlation of the geomagnetic field intensity with the composition of the atmosphere, temperature, climate, volcanism, and other environmental conditions was revealed, it is possible to assume its influence on evolutionary processes as part of the overall complex of environmental conditions. Geomagnetic polarity superchrons ended with mantle plume formation, which produced trap eruptions and initiated Phanerozoic mass faunal extinctions. The sources of the geomagnetic field and plume formation leading to trap volcanism are at the boundaries of the Earth’s inner spheres, which explains their correlation. And their correlation with impact events as one of the causes of extinction can be explained by a cosmic primary cause that lies beyond the confines of the solar system.