User blog comment:Jamintheinfinite/Subnautica Creature Evolution/@comment-28450065-20180331231031/@comment-28450065-20180401165950

The point is that it shouldn't split off at that point. The Cave Crawler, Blood Crawler and Crabsquid should all split off from a hypothesised common ancestor.

I don't think that the Blood Crawler is a descendent of the Cave Crawler either.

Say you have one common ancestor, that splits off into the Crabsquid line, the Shuttlebug line and then a third offshoot which later diverges into the Cave Crawler and Blood Crawler.

And for the Stalker and Lava Lizard I didn't say that Stalkers became Lava Lizards, what I'm saying is that they shared an ancestor a long time ago which was neither Stalker nor Lava Lizard and later diverged into the two species. Obviously they split from each other millions upon millions of years ago and have been independently evolving since.