The Sixth Finger, directed by James Goldstone.
Experiments in accelerated evolution transform a test subject into a man of first 20,000 years in the future, then a million years. He displays powers of mind and mind over mater, becomes arrogant and aggressive, but finally moves past that, wanting to leave the body behind and become pure mind, like an angel.
In this scenario evolution means increased intelligence, prefigured by clear class distinctions: the Londoner lording over the Welsh, the clean over the dirty, intellectuals over laborers and servants.
This is early in David McCallum's US career, and he brings great sensitivity to a role that might have been ridiculous if played differently. He and the makeup artist conspired to retain the character's expressiveness of eyes and mouth:
Notes:
Another "transformed man" plot.
Jill Haworth is Gwyllm's girl, "Kathy". She was offered the lead in Lolita (1962) but Otto Preminger owned her contract and wouldn't let her out of it.
We have a man in a chimp costume. He is a transformed chimp, so maybe that works.
The plot owes something to Pygmalion (1938) and My Fair Lady (1964) with the Professor taking in the dirty urchin and telling the landlady "Clean him up." It is easy to imagine Edward Mulhare as Higgins and in fact he took over the part from Rex Harrison in the stage version of "My Fair Lady".
When still a dissatisfied coal miner, Gwyllm says he wants "to get out from under, away from this dirt and stupidity". When he is a hyper-intelligent man of the future, Kathy says his hatred of the town is all he has left. Which is not quite true: he retains his fondness for her.
The notion that the gross body tethers the pure mind is an ancient idea, still under discussion.
Note that it is Kathy on the machine who brings him back and determines his "just right" level. Men propose, but women dispose.
The evolution machine has a simple "Forward / Back" lever. Didn't the Time Traveler have a similar control?
Gwyllm seems dazed at the end. Are we sure he came back?
The idea of perilous increase in IQ was used in an early Star Trek episode, Where No Man Has Gone Before, coincidentally by the same director.
Photographed by John M. Nickolaus Jr, the first of his nine episodes. He and Conrad Hall are jointly credited with the visual look of the series.
Glenn Gould provides some keyboard Bach, his second IMDB credit.
The commentary track is another encyclopedic effort by David J Schow, series expert. He had a couple of Outer Limits books, now out of print and fabulously expensive on the used market.
In this track he reveals something I had not realized: the show was very much an ensemble effort. Director Byron ("Bunny") Haskins and cinematographer Conrad Hall are not credited for this episode, but they were there and contributing.
He also points out that McCallum grows taller during his transformations, and that this happens on camera. Everyone on set was scrambling around with planks and orange crates just out of frame.