You act as if there was an episode where the crew de-evolved and Barclay turned into a spider.DuracellEnergizer said:
STIII is unscientific, though. Of course, most of Star Trek is to one degree or another, and its not even the worst offender in the lot (TNG, I'm looking at YOU).
http://en.memory-alpha.org/wiki/Genesis_(episode)
Oh.