A good documentary by PBS, available instantly on Netflix. It comes in 3 episodes, the first is about Australopithecus where we split off from other primates, the second is about Homo Erectus one of the first human species, the last is about the Homo Sapien dominance of the other species.
Weird to think that at one time there was more than one kind of Grok running around, possibly interacting.
Basically the gist of it
Grok E=Homo Erectus - Large (a child of 8 was about 5'10") slightly hairy, completely bipedal and larger brain than previous proto homids. Toolmakers
Grok F=H. Floresiensis - "Hobbits" as they are nicknamed, adults about 3' tall, much smaller brains but still toolmakers. Might be a case of insular dwarfism (species that live on small islands tend to evolve into dwarf versions)
Grok H=H. Heidelbergensis - Capable of more complex thought, buried dead, fed older group memebers.
Grok N= H. Neanderthalensis - Larger than us, more muscular, larger brain but with slightly different shape and thus different sizes for different areas, almost exclusively hunters based on bones and tools which were the stone hand ax and large spear, no throwing weapons, seemingly did not eat plants even when available in lull of European ice ages.
PreGrok - H. Sapien - Early us, still some differences, primarily hunter
Grok - H. Sapien Sapien - Survivor of the Toba Catastrophe, which almost led to extinction. Adaptations allowed superior survivability which let to other Groks dying out.