EARTH × LIFE

The Boring Billion

~1.8 to 0.8 billion years ago

Proterozoic · Paleoproterozoic · Statherian

The boring billion is the interval from 1.8 to 0.8 billion years ago, described as free of glaciations and major extinctions, with low oxygen, scarce nutrients and a remarkably stable carbon cycle.

The boring billion is the interval from 1.8 to 0.8 billion years ago. In the usual account, this interval had no glaciations and no major extinctions. The carbon cycle, the circulation of carbon between air, ocean, living things and rocks, was unusually stable. Oxygen remained low and nutrients scarce. Eukaryotes, organisms whose cells have a nucleus, persisted without diversifying markedly. The name describes the stability of the geological record, that is, of what the rocks preserve. It does not describe the stability of life, since sexual reproduction and multicellularity, the state of an organism made of many cells, both appear within this interval.

Why it matters

The complex cell took shape during the most stable interval in the history of the Earth. The stability of the planet therefore did not prevent major changes in living things.

Dating & uncertainty

The name and the idea of stability are both contested. Carbon isotopes, the varieties of carbon atom that differ in mass, keep constant proportions across the interval. But the trace metals of marine pyrite, the metals that this mineral of iron and sulfur contains in tiny amounts, vary considerably. The interval also contains the origin of sexual reproduction, that of multicellularity and the first great diversification of eukaryotes.

Earth history as one day

14:29:049 h 31 min before midnight

if Earth’s 4.54 billion years were compressed into a single day