New Horizons Pluto update; friendly predatory bacteria; Christmas in the lab; human ancestry

Since the epic flyby of Pluto in July, NASA has been regularly downloading staggering images from the New Horizons mission. Pluto is not a dead rock, but a geologically active dwarf planet, with tectonic movements, ice plains, glaciers, dunes and cryo-volcanoes. For an end of year update on the observations and outstanding mysteries, Adam meets Alan Stern, the Principal Investigator on New Horizons, who is still marvelling at the success of this humble craft. Scientists have discovered how a potentially useful predatory bacterium called Bdellovibrio protects itself against its own weapons when it invades other bacteria. Professor Liz Sockett discusses how the work offers insights into early steps in the evolution of bacterial predators and how this will help to inform new ways to fight antimicrobial resistance Science stops for no one .So how are researchers nurturing their experiments over the festive period? Marnie Chesterton has gone on the hunt for scientists for whom Christmas Day will be yet another day in the lab.This year there's has been an explosion of papers of using DNA to reconstruct human history. We've invented new techniques for extracting DNA from the long dead, and for analysing ancient genomes. Professor Matthew Cobb from the University of Manchester assesses recent key developments in reconstructing the lives and population structures of ancient civilisations.Producer Adrian Washbourne