First appearance in the series of Davros, the mad scientist and creator of the Daleks.
A technical innovation in the studio meant that this was the first time the Daleks' guns fired a beam - previously the screen had merely turned negative to indicate the weapon's discharge.
Genesis of the Daleks is one of only five serials in which the TARDIS is not featured.
Two children visiting Tom Baker at the BBC studios were shown Michael Wisher in costume as Davros. At first he stayed completely still, leading them to believe he wasn't real, then when they got close and started touching the switches on his control panel, he suddenly grabbed one of their hands, scaring the life out of them.
It is said that the Last Great Time War (a theme introduced in the revival Doctor Who (2005)) is caused by the events of this story.