1970s sci-fi book about an alien invasion and the aftermath, with the survivors on a moon of Jupiter who called themselves the JLC

Question

I'm trying to identify a 1970s sci-fi book about alien invasion where the survivors were on a moon of Jupiter and called themselves the JLC or the Jovian Lunar Confederacy, Jelks for short. These people survived an alien invasion that decimated the Solar System.

As the system recovered, mankind had become very different from the original look. Survivors on all planets had mutated or bred for specific looks. The survivors on the Jovian Moons had modified their bodies due to reduced resources and had become 3 feet tall, hairless with big eyes (I know what this sounds like).

Now, I think a computer said they needed to track down and destroy the aliens that had attacked them, but they needed to create a breeding program to make the ultimate human who could take down the aliens. One of the participants was a female Jelk who crossbred with a pirate-type man and had a daughter who was raised by a high-ranking official the daughter called him Kofi. I hope this jogs someone's memory as I would like to read it again.

Answer 1

This must surely be I, Weapon, a novel by Charles W. Runyon, first published in 1974.

The humans had been heavily defeated in a war against a race of marsupial aliens called the Vim. The remaining pockets of human civilation lay on the moons of Jupiter:

The sole exception was the Jovian moon-people. At the time of the Vim disaster they numbered only about thirty thousand scientists and their retainers scattered over the moons of Ganymede, Callisto, lo, and Europa. They grew their own food in hydroponic tanks, mined the minerals needed to synthesize their own air and water — in short, were self-sufficient, intelligent, and highly adaptive.

They formed a society called the "Jovian Lunar Confederacy", which became abbreviated to "Jelk". As the OP recalls, these survivors modified themselves genetically to be short and hairless:

Jelks averaged four feet in height, with small bones, delicate features, and unusually large eyes, due to the fact that lights were kept dim in the Ganymede caverns in order to conserve energy. They were hairless as eggs, an evolutionary development which also took place in the underground culture, with its emphasis on purity of air and cleanliness of body.

They began a breeding program to create a supersoldier to defeat the Vim, and eventually bred a man named "Raki" (rather than "Kofi") who met the requirements.

The full story is available from the Internet Archive.