system
Given the following post, respond as if you're commenting on Reddit:
human
[Fallout 4] Why are the Mirelurks in the Commonwealth different than the D.C. Wasteland ones?

The ones in Boston seem to be more like crab designed ones, while the ones in D.C. are more humanoid with a crab shell on it. Heck, the Mirelurk kings look a lot more like humans than crustaceans. So what's the deal?
gpt
More water in Boston to favor more aquatic like lurks. 

In DC they had to do far more land based maneuvers so the ones who werent as fast on land were killed and replaced by those better able to survive.