Are we really related to Neanderthals?

Chris Smith from the Naked Scientists takes on YOUR questions. Why might someone with diabetes lose a limb? How can you predict a dangerous solar flare? Are humans really related to Neanderthals? Do we love water because we evolved from the ocean? What percentage of our brains do we really use? What causes shingles, and what's the best way to treat it? Which parts of the brain are affected when you're stressed, and can cannabis help with stress relief? Plus, the 'smart' insulin that could mean the end of insulin pens...