[Sr. Mints]

Originally Posted by Fuzz

I'm no evolutionary biologist, so I could have this wrong, but I'm not sure it's entirely true only one intelligent species evolved on earth. Neanderthals and humans share a common ancestor, but if you imagine that they stayed separate for longer, to the point where mating didn't produce viable offspring, we could have had 2 intelligent species. Since they successfully mated, it all blended back to one.

Wandering a bit here comma but I just came across an article in my three year backlog

What if a civilization evolved on earth not tens or hundreds of thousands of years ago, but hundreds of millions of years ago and there is simply no trace?

Was There a Civilization on Earth Before Humans?
A look at the available evidence

"[..]When it comes to direct evidence of an industrial civilization—things like cities, factories, and roads—the geologic record doesn’t go back past what’s called the Quaternary period 2.6 million years ago. [...]"

I love this theory so much .