We can tell how old a species is by things like mutations in their DNA and mitochondrial DNA. That way we can tell when species break off from each other.
Also we know human brains tripled in size in the last 2 million years.
I think I have heard him propose that civilization is around 30,000.
As far as no trace being left over. If we disappeared, how much evidence would be left for someone to find in 12,000 years? Not much, maybe plastic? But by then something may have adapted to eat it.
In 12,000 years? Lots. Even if all our other building materials eroded away, we make plenty of buildings of hard stone. They’ll be as permanent as Stonehenge. Not to mention the materials that do erode won’t evaporate and will leave rather traces rather obviously the result of a large civilization.
And if that fails to convince everyone, the world is full of road cuts and tunnels that are quite obviously not natural erosion. Building road tunnels and road cuts in places where there could naturally be lots of running water is generally a thing to avoid.
We have evidence of human activity significantly older than 12000 years now. Why would evidence of an advanced civilizations be harder to find? And your evidence of the steady progress of human development that goes back a few 100,000 years. There’s no gap to insert an advanced civilization that magically disappeared.
See before mankind even existed there was a omnipotent power on the earth that had land air and sea travel mastered …… that helped foster peace and understanding through out the world and had advanced sciences and even world wide sport that wouldn’t be discovered for millions of years
They had such concepts as conservation inter racial peace and harmony we cant even get back to today
Sadly their greatest invention was lost because there astronomy hadn’t advanced enough to catch the big rock that would doom them all …. The time tunnel!
Even though it took millions of years for humans to understand their ruins and notes when the ancients finally figured it out… it took us out of the mud and caves and started us on a path of enlightenment
It was the trolodons and the benevolent and omnipotent dinosaur train industries!
I mean it makes more sense that the worlds smartest beings until the human race formed all of this before we even existed and all the ancients did was evolve until their intelligence could comprehend such advanced learning …… All the other theories are space gods and other disproven junk
So what does my fellow compatriots of the dope think ?
If any prior civilization existed, they were super considerate, only mining the really hard-to-get ores and only pumping the really deep crude, leaving the easy stuff for our 18th/19th century ancestors to find and use to start this most recent industrial civilization.
Anyway, they didn’t. The dinosaur one double-didnt. Exist that is.
I would say that the odds are so close to nil as to not warrant discussion except in a “what if” sense. Is it possible some past civilizations were more advanced/complex and adapted than we give them credit for? That one I will not just buy but believe.