Jingszo !

Humanity may not be extraordinary but rather the natural evolutionary outcome for our planet and likely others, according to a new model for how intelligent life developed on Earth.

The model, which upends the decades-old "hard steps" theory that intelligent life was an incredibly improbable event, suggests that maybe it wasn't all that hard or improbable.

In the new study, the researchers proposed that the timing of human origins can be explained by the sequential opening of "windows of habitability" over Earth's history, driven by changes in nutrient availability, sea surface temperature, ocean salinity levels and the amount of oxygen in the atmosphere.

Given all the interplaying factors, they said, the Earth has only recently become hospitable to humanity—it's simply the natural result of those conditions at work.