This week on the show Claire takes a look at IVF babies with three genetic parents; two parents for the nuclear DNA, and a different parent passing down their mitochondrial DNA. This new technology is assisting couples with mitochondiral diseases to have healthy babies. Also on the show this week Chris goes to the fringe of physics and takes a closer look at Modified Newtonian Dynamics; a theory some scientists think may explain the way galaxies move and interact without relying on dark matter to balance the equations. Do you put yourself at risk on a daily basis? You may be. Turns out humans aren't that good at estimating risk, which can be more accurately measured by a unit called "micromort", or a one-in-a-million chance of dying. The results might surprise you...