Scientists have been speculating for some time about the effects that Neanderthal DNA might have on modern humans, but detailed research appears to fairly recent. According to Phys.org (2016), "... the first study that directly compares Neanderthal DNA in the genomes of a significant population of adults of European ancestry with their clinical records confirms that this archaic genetic legacy has a subtle but significant impact on modern human biology.
"'Our main finding is that Neanderthal DNA does influence clinical traits in modern humans: We discovered associations between Neanderthal DNA and a wide range of traits, including immunological, dermatological, neurological, psychiatric and reproductive diseases," according to one researcher.
Among other things, the study found "that a specific bit of Neanderthal DNA significantly increases risk for nicotine addiction. [Researchers] also found a number of variants that influence the risk for depression: some positively and some negatively. In fact, a surprisingly number of snippets of Neanderthal DNA were associated with psychiatric and neurological effects ..." (See next post).
Comment: I've been addicted to nicotine in one form or another for most of my life. It's strange to think that I could be more susceptible to this kind of addiction because one of my distant ancestors bumped uglies with a Neanderthal hundreds of thousands of years ago.