Last, Best Hope of Humanity (achievement)

Last, Best Hope of Humanity is an achievement/trophy in Fallout 3.

Requirements
Reach level 20 while having Good Karma.

Behind the scenes
In Fallout 2, according to President Richardson, a modified version of the Forced Evolutionary Virus is the last, best hope of humanity since it can cleanse the mutation. This karma title and achievement is probably a reference to this.