All extant human species are descendants of Earth humans (homo sapiens sapiens).
The Terrans (h. terrenus terrenus) are the most numerous human species. They see themselves as the direct descendants of Earth humans in spite of fairly extensive genetic modification. They're not adapted to any particular environment, but are augmented for increased lifespan, increased resistance to diseases and various side effects from space travel.
Due to their space adaptation, there's no recognized Terran Spacer subspecies. Instead, that term refers to Spacer cultures exclusively, though many of those have additional adaptations to life aboard spacecraft.
The Hyperians (h. t. hyperionis) are the high-grav subspecies of Terrrans. They're marginally shorter and more muscular than their Terran kin and can handle high-gee acceleration for longer times. Natives of the super-Earth Hyperion in the Procyon system, they have settled many high-grave worlds across Terran space.
The Wastelanders (h. timendus timendus) are adapted to life in red dwarf systems. They're resistant to UV, have cat-like eyes with excellent low-light vision, pointy teeth and strong jaw muscles, and short claws instead of fingernails.
Wastelanders have a reputation as fierce fighters, and while they cultivate their combat skills, they're not more aggressive than other human species.
The Mananga (h. t. stellaris) are the Spacer subspecies of the Wastelanders. Beside the typical Spacer adaptations, they have prehensile toes.
Their name is the Creole descendant of the Swahili term mwanaanga, meaning "astronaut".
The Baridans (h. t. robustus) are the high-grav subspecies of the Wastelanders native to the icy super-Earth Cold Heart in the Proxima system. They're more muscular and can withstand high-gee acceleration for longer periods of time.
A significant minority of Baridans also has Spacer adaptations, but they're not considered a separate subspecies.
The Hellhounds (h. hybridus ignifer) are a human hybrid species descended from Wastelanders and adapted to life on volcanically active worlds. They're a hybrid species with alien genes spliced into their DNA, allowing them to breathe sulfur compounds and hydrogen as well as oxygen. They have bone blades on their forearms, bright yellow blood and red eyes without visible pupils.
Like their Wastelander ancestors, they have a reputation as fierce warriors. While not untrue, the majority of them prefers to solve conflicts without bloodshed.
The Lucidans (h. lucidanus lucidanus) are a posthuman species adapted to life on cinder worlds and extensively augmented. Outwardly human at birth, not many of them stay that way. Beside their adaptation and extensive augmentations including inborn techno-telepathy and regenerative nanites, they have the highest rate of uploading and cosmetic genemods of all human species.
They're natives of the terrestrial planet Vultur Ascendent in the Lucida Lyrae (Vega) system. They consider themselves enlightened and their use of technology the only sensible way of life.
The Dryads (h. l. dryas) are a Lucidan subspecies adapted to life in Dyson trees, semi-organic habitats grown in space. They have the same adaptations as most Spacer species, but are reliant on their trees for long-term survival. That limits their ability to travel only somewhat, as most Lucidan ships carry small Dyson trees as part of their life support systems.
The Irrlichte (h. l. stellaris) are the Spacer subspecies of Lucidans. They have dark, bioluminescent skin, which gave them their name. Unlike many other Spacer species, their ability to handle high-gee acceleration is limited, and most Irrlichte therefore live and travel on sail ships.
Their name comes from the German term Irrlicht (plural: Irrlichter, less commonly Irrlichte), meaning "will-o'-wisp".
The Carcosans (h. carcosanus carcosanus) are a human species adapted to life on pulsar planets. Pale-skinned and black-eyed, they're said to have alien genes spliced into their DNA. They're highly resistant to hard radiation and have excellent hearing, night vision, and an adaptive thermal sense.
The Sirens (h. c. aquaticus) are the aquatic subspecies of Carcosans. Outwardly human, have webbed fingers and toes, shark teeth and prehensile tentacles instead of hair. They're amphibous and need to keep their skin wet.
The Gwyllion (h. c. stellaris) are the Spacer subspecies of Carcosans. They can spend their entire life in microgravity, but also withstand high-gee acceleration better than most Spacers.
The Martians (h. sapiens martis) were the first bioformed human species adapted to another planet, namely Mars in the Sol system. Nowadays, the original species is almost extinct, inhabiting a handful of arid low-grav worlds.
The Titanians (h. sapiens titanis) are adapted to the environment on the Cronian moon Titan. Descended from Martians, they share their adaptations but are capable of breathing their native moon's atmosphere. Since Sol was abandoned, Titanians have become even rarer. Most now live in habitats with environments similar to their homeworld.
Gaians & Demetrians
The Gaians (h. sapiens gaiae) and their high-grav kin, the Demetrians (h. s. demetros), are very similar to Earth humans. They consider themselves their natural descendants and make it a point to use only minimal genetic modification. Since they're much less numerous than the Terrans, they're often overlooked.
Gaians and Demetrians inhabit around a dozen Earth-like worlds and super-Earths orbiting Sun-like stars on the outskirts of human-settled space.
The Europans (h. hybridus europanis) are an aquatic hybrid species native to the Jovian moon Europa. They're adapted to life underwater in the cold and dark of their homeworld. Since Sol was abandoned, Europans have settled a few similar moons.