Doctor Jonathan Gediman was an antagonist in the 1997 sci-fi film Alien Resurrection. He was a research scientist with the United Systems Military who worked aboard the USM Auriga as part of a team tasked with cloning Xenomorphs using alien DNA salvaged from Fiorina 161. Mentally unstable, Gediman bore an obsessive fascination with the Xenomorphs, as evidenced in the way he would taunt and torture his captive specimens. He was portrayed by Brad Dourif.
Dr. Gediman and his team were responsible for engineering a clone of Ellen Ripley, a woman who had repeatedly dealt with Xenomorphs in the past. At the time of her death 200 years prior, Ripley was carrying an embryonic Xenomorph queen and traces of DNA from both the parasite and its host were recovered from Fiorina 161 by the Weyland-Yutani Corporation. While Weyland-Yutani eventually went out of business, they had already conducted considerable research on the Xenomorphs and had transferred that research to the United Systems Military. When Gediman and his team took on the project in the late 2370's, they used cloning technology in order to produce a copy of Ripley, whose DNA was intermingled with that of the alien she had been carrying.
Gediman produced several Ripley clones, the majority of which were hideously deformed hybrids of both human and Xenomorph. In 2381, Gediman's team finally succeeded in producing a viable clone of Ripley which incorporated Xenomorph genes into her own biological makeup, thereby granting her superhuman strength, heightened senses, acidic blood (though not to the extent of pure Xenomorph blood) and an empathic link to nearby Xenomorphs. This clone, designated Ripley-8, also carried a cloned Xenomorph queen embryo within her, which Gediman surgically removed from her before it fully matured. With a queen in his control, Gediman had the means to produce more Xenomorphs, so long as the military continued hiring mercenaries to kidnap people to use as Facehugger hosts.
While Dr. Wren had originally planned to terminate Ripley's clone, Gediman convinced him to let her live so that he could continue studying her. Of all the scientists aboard the Auriga, Gediman in particular was fascinated and impressed by Ripley-8's abilities, particularly her genetic memory, inherited from the Xenomorph genes in her body, that allowed her to remember elements of Ellen Ripley's life. Once the Betty arrived aboard the Auriga with kidnapped hosts for breeding several Xenomorphs, Gediman observed the implantation process. Gediman became fascinated by the fully-grown drones, spending a large amount of his time studying and interacting with them. During this time, Gediman taunted the aliens and would punish them if they became aggressive by using a liquid nitrogen spray to pacify them. One of the aliens paid close attention to Gediman and the button he used to activate the spray, learning how the device was operated.
The cloned Xenomorphs would later escape from confinement after killing one of their own, using its acidic blood to dissolve the floor of the containment cell and make several holes in the decks beneath. When Dr. Gediman later opened the cell to investigate the containment breach, he was grabbed by one of the creatures and taken to the lower decks where the aliens would build a new hive.
Near the end of the film, Dr. Gediman - now cocooned and likely implanted with a Chestburster - bore witness as Ripley-8 had been captured and brought before the alien queen. Like Ripley had inherited Xenomorph genes, the queen that had been extracted from her had also inherited human DNA, developing a uterus as a result. A mesmerized Gediman watched with rapt fascination as the queen gave live birth to a new human-Xenomorph hybrid, remarking the newborn creature as "beautiful". The Newborn, however, did not regard the queen as its mother and killed it, instead viewing Ripley as its true parent. The creature soon turned its attention to the rambling Gediman and approached him, using its teeth to break into the doctor's skull and tear out his brain.