Fish elections, cholera, evolution...

How combining technologies has enabled the identification of the gene faults linked to cancer, how injections into the groin lymph nodes is a more effective way to treat allergies, why we now have a better view of another solar system, how sticklebacks select a leader, how cholera outbreaks can be predicted from space, and why a specimen of Homo erectus sheds light on our evolution. Plus, in 'Stuff and Non-Science', are silencers really as effective as Hollywood would have us believe?