A 27.5-Million-Year Rhythm Ties Earth’s Major Crises
New analysis of 89 major geological events over the last 260 million years strengthens evidence for a ~27.5‑million-year cycle linking Earth’s largest upheavals (extinctions, oceanic events, flood basalts, sea‑level shifts) with a weaker ~8.9‑million-year cycle. The study suggests multiple Earth systems may respond to a shared, long‑term driver, but the exact mechanism remains uncertain and the idea is still debated among scientists.