In the UK, successively invaded & occupied by Angles, Saxons, Jutes, Vikings & Normans among others, our aboriginals would be the Welsh

Weeeeeeellllllll

The Scots & Picts would argue on that one. And doesn't anyone love the Bell Beaker Folk? And as for Neanderthals we Brits are all a bit Neadnerthal. Say 2%.

It is a very curious question that I saw posed, But the analogy was that of mules, the union of donkey and horse produces infertile males 90% of the time, so was the demise of Neanderthals accelerated by such a cross-breeding?

2% of me thinks so!