Interesting science bit - it seems over thousands of years that people in the east part of Eurasia reproduce at an older age than the people on the west side of Eurasia:

Different historical generation intervals in human populations inferred from Neanderthal fragment lengths and mutation signatures

The researchers also support the idea that there was just one admixture event of Neanderthals with modern humans. This is does not cover the later Denisovan admixture event.