well humans didn't actually evolve from neanderthals since both existed at the same time, they are two different species who share common ancestors. So this doesn't really have to do with evolution per se, but now we know that there are humans who share common DNA with neanderthals meaning they must have interbred at some point.
evolution is the result of inter-species and intra species competition, which can occur interbreeding and speciation. Like its cool they have some genetic proof but I thought many scientist had already agreed that a major cause to the neanderthals extinction was interbreeding with homo sapiens.