Coevolution of Earth & Life
Simulate the Great Oxidation Event (HS-ESS2-7). Observe how the emergence of photosynthetic life fundamentally altered Earth's atmosphere, geology, and paved the way for complex aerobic life.
Simulation Controls
Add early photosynthetic life to the anoxic ocean.
Archaean Eon Environment
Scientific Argument (HS-ESS2-7)
Claim: Life and Earth's physical systems coevolved, with biological processes driving major geological and atmospheric changes.
Evidence 1 (The Sink): Early oceans were full of dissolved iron (Fe²⁺). When cyanobacteria evolved photosynthesis, they released O₂ as a byproduct. Initially, this O₂ did not build up in the atmosphere; instead, it reacted with dissolved iron to form insoluble iron oxides (rust), which precipitated to the ocean floor creating Banded Iron Formations (BIFs).
Evidence 2 (The Outgassing): Once the ocean's iron sink was exhausted, free O₂ began outgassing into the atmosphere. This changed the sky from a methane/CO₂ haze to a clear blue, and allowed the formation of the stratospheric Ozone (O₃) layer, shielding Earth from UV radiation.
Evidence 3 (New Life): The oxygen-rich environment was toxic to many early microbes, but it allowed for the evolution of new, energy-efficient aerobic metabolisms and eventually complex eukaryotic life.