[rbanffy]

We don't have evidence either way. As we are now a single global civilization, we may be more resilient, but imagine what would it take to wipe out the Sumerians or the Egyptians at their peaks and how little of them would be left a million years after.

Imagine then a species of dinosaurs that invented written language, started melting metals and built roads to transport their goods from production centres to specialized high-density habitation complexes, only to be wiped out by a mountain falling from the skies.

If they happened to live near the ocean shores, nothing would be left just a few hours after the impact. We'd be extremely lucky to find a fossil of a dinosaur wearing jewelry or any other indication of cultural development.

[ETH_start]

You're right. I thought you were referring to a civilization like our contemporary one, with the technologies and productive potential available to it. The scenario you describe, of a Bronze Age civilization being wiped out in one of the mass extinction events that life on Earth faced, is plausible.

I'd add however that it didn't take long at all on a geological timescale for our civilization to go from its inception, with the invention of agriculture, to having advanced industrial technologies, and I assume the same would apply to other civilizations. So the probability of a civilization having emerged but having faced a cataclysm in the short span of time it would have taken for it to achieve the level of sophistication of our civilization is quite slim.

[rbanffy]

I still don't think we are past the Great Filter yet. When we have 1M+ people living outside Earth's atmosphere in 10+ independent self-sufficient habitats, then I'll breathe in relief.

[speed_spread]

I'd add that the habitats should be moving away from each other and from Earth fast enough to make any physical interference too costly for sustained war. Communication should be encouraged though, with provisions against psyops.