The humans, montanes, and nerites are separate species within the same genus, having diverged about one million years before human civilization appeared. While hybridization is possible between the species in all three combinations, the resulting offspring are almost always sickly and infertile.
The montanes are graceful, furry creatures with flexible limbs adapted to climbing around on rocks and cliffs. Music permeates their existence; they communicate as much through singing as through speech. They live in villages and towns on mountain summits, but come down into the valleys in groups to gather food, water, and wood and to defend their territory, both from rival montane villages and from encroaching humans.
The nerites are adapted to a mostly aquatic life, with webbed hands and feet for swimming and the ability to hold their breaths for long periods. They don’t speak at all, but nevertheless seem to coordinate their actions, suggesting they communicate in a way beyond human understanding. They spend most of their time in the shallow waters along the coasts, only coming ashore to gather wood and other raw materials. Most humans who venture onto the ocean do not return, and those that do report frightening hallucinations.