The story of human evolution is long and complicated, but the simple truth is - you're only here because your ancestors got lucky. Plus, we wind the clock back to the very start of human life, and discover how new research is pushing back the frontiers of human embryology. Plus a suitably festive gene of the month. This is the Naked Genetics podcast for December 2016 with me, Dr Kat Arney, brought to you in association with The Genetics Society, online at genetics.org.uk.