Researchers discover that Neanderthal genes are in the genomes of 1-4% of modern Euroasian humans (absent from Africans).
http://news.bbc.co.uk/2/hi/science/nature/8660940.stm
It's been speculated that perhaps Neanderthals became extinct from Europe and Asia due to genetic mixing with Homo sapiens, but previous research could not find evidence.
For what it's worth, Neanderthals were not unintelligent thugs like pop cultures portrays them.