An Upper Palaeolithic Proto-Writing System and Phenological Calendar

"Europeans have ancestry have that goes back beyond 40000 BC"

I cannot figure out what you mean, but I think you misunderstood what I wrote. The article that I linked to says that, of the European DNA that has been captured from samples from 40,000 years ago, no trace of the DNA can be found in the modern population, therefore it seems the Homo Sapiens who were alive in Europe 40,000 years ago eventually went extinct. There was a dramatic change in the DNA in human samples found from 15,000 years ago, and this DNA is found in modern populations. Therefore, the early populations of Europe were wiped out, and replaced by the new populations that arrived 15,000 years ago. It is believed that there were human populations that expanded from Anatolia and which spread across Europe 15,000 years ago. Based on the DNA evidence, this new population completely replaced earlier populations. None of the earlier populations survived, since none of their DNA is found in modern populations.

You wrote:

"otherwise your statement suggests Europeans were beamed here from an alien planet ~42k years ago"

I wrote:

"Europe was re-populated around 15,000 years ago by a group that expanded from Anatolia."

I think it is more likely that the new population came from Anatolia. This is easier to believe than thinking that the new population came from an alien planet.