User blog comment:Spartan0700/Dark Energy: What Would You Do?/@comment-5258512-20120805041409/@comment-3062992-20120805225810

All I know is that the writers were originally going to pull the Star Trek card and say that humanity is "super-special," instead of just unique like any other species. Mordin said during his Loyalty mission when he and Shepard find a human corpse in Maelon's lab that humans are more genetically diverse than any other species in the galaxy, yet another foreshadow that hints at the reaper's interests in humanity.

Therefore, in the Dark Energy ending, a human reaper would have solved the Dark Energy problem. The caveat is that the entire human race needed to be harvested, turned into a Collector milkshake and turned into the super-duper reaper that would save the galaxy.