Monsters In Space And Time.
Morlocks and Eloi are our descendants, devolved humanity.
Thals are fully humanoid aliens as were the Daleks before their mutation. Now, the latter, like Wells' Martians, survive inside protective machines.
Tolteca, Raven and the Gwydiona are our descendants, human inhabitants of extra-solar planets. Mountain apes are anthropoid animals without tools or language. Such parallel evolution is common on terrestroid planets.
Anderson's alternatives to Morlocks and Eloi are the Danellians, not devolved human beings but the next evolutionary stage after humanity. Human beings might regard them with either awe or fear.