"As in “My Three Crichtons", we have an episode from a science fiction show that is presenting evolution as something for which an organism’s genes have a solid, unchanging blueprint: an organism’s evolutionary path is preset, and by speeding up the passage of time relative to the individual, processes that would ordinarily take centuries or even millennia, like evolution, can now happen in a matter of days. What might have made more sense, if Star Trek insists on speeding up time, would be an accelerated birthrate as a result of this accelerated time, meaning that hundreds or even thousands of generations inherited slight genetic variations, were selected for or against, and (relatively) slowly evolved into the legged catfish-like creatures that the crew of Voyager discovers. In choosing not to take this route, however, “Threshold” is advancing an understanding of evolution that presents it as a linear progression encoded in an individual’s DNA, and thus, through some kind of mystical science, an individual could realize his species evolutionary potential within his lifetime."