The glyph of Europan Nation. Note the almost literal adaptation of the original JGA corporation symbol
Europanthropus aquaticus The Jupiter moon Europa was a veritable treasure of ice and volatiles, and together with the other ice mines of the jovian moons one of the economic cornerstones of the Gengineer Republic. The loss of control over the relatively easily accessible source of water was a major problem for the inner system orbitals, who were forced to pay exorbitant fees for their water. At the same time many of the tweaks of the Republic found Europa somewhat lacking. The inner ocean predicted in the 1st century a.t. existed, but was quite lifeless (excluding the remnants of the 383 hoax perpetrated by White Fraction geneticists). Many believed Europa ought to be colonised and if not terraformed at least ecopoiesed.
In 495 a.t. Jovian Genetics & Adaptation began the process of developing an integrated Europan ecosystem and humanoids adapted to a life in the dark, salty high pressure seas of Europa. The design was ambitious: a fully aquatic human, equipped to deal with low temperatures and extreme pressures as well as the anoxic chemical environment of Europa. The undersea biospheres of JGA developed a tweak form with a thick black skin covered with chromophores for signaling and sensitive to vibration. Legs were removed in favor of a flexible swimming tail, while the head was streamlined. The result was a being not unlike a deep sea man-shark. The largest changes were metabolic. JGA found that it was very hard to maintain a human-temperature metabolism in the Europan environment, and eventually settled for a radical redesign that made the Europans cold-blooded. Compared to ordinary humans they were sluggish, at least when in cold water, but as they warmed up due to the environment or exertion they accelerated and could for brief periods easily outspeed a baseline human.
When the nanodisaster hit, JGA was temporarily spared. Their remote undersea bases were beyond reach for the moment but totally isolated. The ruling AIs had the choice of spending their scarce resources on the Europans or their human employees. In the end the AIs, possibly selfishly, decided the Europans had the best chances of continued survival and ordered the expenditure of most resources on finishing the project giving the young Europans all available technology, education, and information. The AIs continued to protect the Europa ocean with their Blue Goo, but allowed their human employees to slowly die out or freeze themselves for an uncertain future.
The Europans were cast into a huge, dark world with very little life. The undersea ecology designed by JGA was sparse, mainly derived from terrestrial deep sea springs. The Europeans settled along the many volcanic rift valleys, gathering worms and crustaceans for food, playing with their technological toys but not really having a strong incentive to do anything. Over the decades, observed with growing despair by the AIs in their empty bases, the Europans developed into a primitive hunter-gatherer culture migrating across the seafloors of Europa. There was no incentive to develop or retain a complex culture.
They were stuck in a technological trap: without fire they could not fashion metal or develop advanced chemistry, so they would remain primitive forever. The alternative would be to give them some kind of new technology that could be developed indefinitely. Nanotech was out of the question, too dangerous and powerful. But biotechnology might be doable. The AIs developed basic "tools" for a biotech technology, essentially simple lifeforms that could be combined and changed like lego blocks or perhaps modeling clay. They taught the Europeans to use them, and watched the results.
Biotech helped the Europans to survive and soon prosper. They designed their own pets and farm animals, creatures excreting suitable building materials and many forms of symbionts. Of course, despite the safeguards put in by the AIs runaway creatures caused local ecological disasters (good learning experiences, the AIs opined) and often the symbiotes had strange side effects (often deliberate mystical hallucinations/illuminations). Over the years a biotechnological, partially nomadic but promising culture emerged.
It is unknown what the Europan culture would have become if it had remained undisturbed, but in 1022 they were contacted by explorers from the newly formed Federation. The AIs tried to manage the situation but found themselves far outclassed by their younger Federation relatives. The Federation wanted to develop Europa (at this time there was even some talk of stellifying Jupiter and terraforming the moons), and the Europans were ideal for the task. Over a span of just a century European society went from a simple pre-industrial society to a part of the interplanetary community. The strain was rather extreme, and many Europans experienced serious future shock and anomie. But many prospered, seeing new possibilities in the BeyondWorlds and the various projects the BeyondWorlders wanted to involve them in.
Europan biotechnology also proved to be useful, especially since it circumvented many of the Federation regulations on replicating technology by being a "traditional and indigenous technology". Since controlling and managing it required much experience, skilled bioshamans were in high demand throughout the 1000-1100s (eventually more streamlined forms of biotechnology and nanotech superseded the old Europa technology, but "Europan-style" biotech retains an air of antique quaintness that tends to be revived around every five centuries or so in the Inner Sphere).
In the end, the Europans dispersed across human space, clading into many deep ocean aquatic lines. Especially well-known are the Iri-Kakkak Clade of Poseidon and the Deep Mekelonites of Mekelon, who have extensive investments in relativist starships and exploration.
A population of about 6 million still live on Europa, almost all E. aquaticus. On surface habitats are a small number of the highly modified and amphibious E. semiterrestralis living together with various beyondworlders (non-Europans). In the orbital bands around Europa those two species along with E. spatialis coexist with beyondworlders. There are believed to be at least several dozen (and very possibly several orders of magnitude more) species-distinct clades dispersed through colonised space, the most well-known being E. spatialis, E. poseidonensis, E. aster, E. neospatialis, E. cosmoi, E. thallassophilia and E. bythomekelonis.