Ozzy Osbourne is English and apparently
a fraction of his chromosome 10 is of Neanderthal origin.
I wonder if that applies to the rest of England?
It's not just Ozzy. Recent research suggests that
all Europeans are descendants of Modern Man/Neanderthal Man hybrids. Even more controversially is the theory that Oriental peoples are hybridised with a separate form of Proto-man, Homo-Erectus. Chinese state education teaches millions that they are descended solely from Homo Erectus (I don't think it's taught all over the country, but certainly in many schools), but genetic studies have unsurprisingly proven this as nonsense. The hybridisation theory is still very possible.
Obviously - there has been subsequent cross transfer of East & West since then. For instance, the genetic signature of Genghis Khan has been found all over Europe as well as Asia, so this is not meant as a divisive comment between the oriental and occidental.
Our genetic history is an extremely complex blend of wave upon wave of human movement. Any argument based upon racial purity is patently ridiculous. Nationality is a cultural construct, and should be respected as such.