�y��vlog

Both Mills and Purdue University astrobiologist Stephanie Olson, who was also not involved in the study, were impressed by how well the new results match the history of atmospheric oxygenation, including the famous two-step rise and the intervening “boring billion” years—when oxygen levels flat-lined, and day length also stalled at 21 hours.

The evolutionary step from a single-celled eukaryote to the emergence of multicellular life took a long, long time—about a billion or so years, during which so little changed on Earth that it's been called the "boring billion."

A striking pattern emerged: a steady thinning of the crust throughout the so-called boring billion.

The team suggests that this slowdown resulted from changes in how heat was distributed on Earth's surface during the boring billion, when the continents largely clustered in a single supercontinent.

In the eon between 1.8 and 0.8 billion years ago—a time dubbed the "boring billion"—the continents seemed to grow progressively thinner.