Galactic Forcing Increases Origination Of Marine Microplankton

The continuous flux of Galactic cosmic rays that bombard Earth’s atmosphere creates ionizing radiation that can damage the DNA of living organisms.

While this radiation on Earth is relatively constant in the short term, large and long-scale fluctuations are expected with a period of ∼63.5 million years.

As the Solar System moves above or below the Galactic plane during its oscillatory motion about the Galactic center, the Galactic magnetic shielding weakens, allowing more cosmic rays to reach Earth and trigger mutations in organisms.

We identify a significant correlation (weighted global p-value: 1.25×10−4, or 3.72σ) between the Solar System’s Galactic oscillations and the origination of marine zoo- and phyto-microplankton genera over the Phanerozoic.

When we restrict the analysis to time intervals during which all four groups coexisted, a post-trial significance of 4.52σ emerges. Our findings suggest that changes in biodiversity have been significantly influenced by long-term Galactic forcing.

Solar system moving in the Galaxy as viewed from above the plane (Original credit: NASA/JPLCaltech/R. Hurt (SSC/Caltech).

Péter Ozsvárt, Emma Kun, Imre Bartos, Zsolt Gy. Márka, Szabolcs Márka

Comments: 26 pages, 6 figures. Accepted for publication in Paleoceanography and Paleoclimatology
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2509.04165 [astro-ph.HE] (or arXiv:2509.04165v1 [astro-ph.HE] for this version)
https://doi.org/10.48550/arXiv.2509.04165
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From: Emma Kun
[v1] Thu, 4 Sep 2025 12:38:53 UTC (2,893 KB)
https://arxiv.org/abs/2509.04165
Astrobiology,