At the beginning of this evolutionary period, these descendants of the earliest toolmakers were beginning to look half-human.
They weighed 123-145 pounds, with 800-1000 cc. brain volume (roughly halfway between the toolmakers' 600-700cc. and modern humans' 1350cc.) They had developed an external nose, human-length arms (as opposed to long, chimp-like arms), and a human-shaped chest cavity.
Their predecessor's dark chimp-like hair was gone by about 1.2mya. This change was likely due to sexual preference. Without fur, their skin turned from pale (like chimps) to dark under the African sun.
Males and females became more similar in size. Scientists believe that this indicates a behavioral transition from separate male and female hierarchies to the beginning of the "pair bond" system, wherein a male took greater interest in protecting and feeding the mother(s) of his children.
At some point in this long evolutionary stage (archaeologists still aren't sure when), they achieved control of fire. This permitted cooked proteins and carbohydrates, expanded human activity into the night hours, and afforded protection from predators, thus enabling these pre-humans to proliferate.
These pre-humans first expanded to the extremities of north and south Africa, and by roughly 1.7 million years ago, they had migrated out of Africa and ranged far and wide across Eurasia. Archaeologists have found pre-human sites from Morocco to Southeast Asia.
None of these archaic humans had any intention of conquering a continent, or even "migrating" as we use the word. Their populations and territories expanded in tiny increments over vast periods of time.
This slow expansion followed their lifestyle. All pre-humans (and humans, too, until roughly 15,000 years ago) were hunter-gatherers, just like their chimpanzee ancestors. This limited the size of tribes, since only so much food can be foraged within a half-day's walking distance -- say, ten miles.
Even in food-rich environments, hunter-gatherer bands are limited in size because they are egalitarian and lack a hierarchy with dispute-resolving authority. If they grow beyond 100 or 150, concensus becomes more difficult, quarrels become more frequent and a group will split off, typically along kinship lines. The departing group, rather than consciously embarking on a journey, will simply walk far enough to find a new foraging territory, perhaps just 20 miles away. After a generation or two, this repeats itself.
With all our pre-human and human ancestors, this was the gradual pattern of expansion. Over a period of a million years or so, populations were strung out sparsely along river valleys from Spain to China and north to the great ice sheets.
Once separated from the mother population in Africa, they followed their own evolutionary paths, with a European lineage evolving into the Neanderthals.
Meanwhile, toward the end of this nearly-two-million-year stage of evolution, the pre-humans evolving in Africa had become totally human-looking, with fully human skeletons and modern faces and skulls. They had reached modern human brain size. They invented the first sewn clothing and made other relatively minor advancements. However, they kept using the same stone tool kit as their pre-human predecessors.
They had the capacity to be fully human, but something was blocking them from realizing their potential. That something was language. Without it, the complete suite of modern human behaviors was beyond their reach.
So life for them continued much as it was for their ancestors: living in caves, surviving hand-to-mouth, and almost constantly at war with other tribes. They must have been very human-like, however, with the females fixing each other's hair and doting over babies, the young males wrestling, running, and getting in trouble, and the adult males preoccupied with the females when they weren't doing battle.
However inarticulate they were, their large brains must have enabled them to appreciate a glorious sunset, marvel at the stars, and be conscious of questions and mysteries surrounding their existence.
But they were in stasis. Without even an oral history, they wouldn't have known that thousands of generations were passing while they marked time.