OutTack, FarTack, HomeTack -- novels by GS Boughton in the DeepStorm trilogy
MANKIND'S ONGOING EVOLUTION
Fimans represent a whole new chapter in the evolution of mankind. But more than that, Fimans are as huge a step in the evolution of life as when fish first walked on land. These few are set to pave the way for life, apart from microbes that may have spawned across space, to leave the Earth's surface and tame the universe. In that way it is intended for mankind to stop overpopulating Earth, and instead find an Earthly haven in space. And, as architected by Tachel, in their new environment they will have nature with them all the way. Those precious species, dispersed to so many different worlds, will finally be free of mass extinctions.

This new breed is physically adapted (genecrafted), from a genetic modification carried out at birth, to live indefinitely in the ZeroG environments of space. That was an imperative for the programme to populate space, both GEM and GAM, to have been considered on any meaningful scale. It is also a requisite for getting the succeeding Questor Mission approved.