Humanity is an evolutionary accident.

Life appeared very early on our planet. In all likelihood, it was born more than one discrete time.

That life has persisted despite extremes and cataclysms. Over time, multicellular life has always thrived, even after the largest of extinction events.

But of all that history, only man reached space.

And would Man have arisen without an asteroid causing the extinction of the dinosaurs?

Would Man have arisen without the climate shift that forced our ancestors to abandon the safety of the trees and walk upright on the plains?

Would man have arisen without the Ice Age that winnowed the competition?

How many of the chance planetary events that occurred over the history of Earth were necessary to produce one single intelligent bloodline? And even then only one species from that line survived. And humanity came close to outright destruction many times in our early history.

Life may be common, but do we have any reason to believe intelligent life can occur but by the rarest of chance evolutionary forces?