How and why the man apes separated from the rest of the apes.

 

Okay, we go back in time to where in the record we find the first ape-like 

creature.  Now we know there was, at some time, a community of apes

that somehow supported a branch that became man.  So then the

question is why would apes living together suddenly begin to separate

into different groups?  Well, one answer is that as they mutated one

group would look or act differently than the others and that might cause

them to stop caucusing with the main group.  But, I'd venture that

it's more likely that it would take more than mere appearances to 

cause a group to separate, mainly because of the safety provided by

numbers.

Instead, I'd propose that a few members of the group of apes, which 

had a language of perhaps 10 words, found that they could understand

and use a few more words and that over the course of months their

vocabulary began growing to perhaps as many as several dozen words.

Some of the other apes would have been unable to understand the new words

or keep up with the growing vocabulary.  That would have made attempting

to speak with the larger group something like talking to trees. That would

be frustrating enough to cause the "speakers' to keep themselves apart

from the "non-speakers" who could still only utilize the same old 10-word

vocabulary.  Over time the separation would grow greater as the number

of "speakers" grew to a size where numbers were sufficient to provide

protection of group. 

It wouldn't take very much in the way of a leap of intellect to begin this

separation. All it would take is a slightly increased ability to comprehend

more, that would be enough to cause proto-humans to separate from the

apes and begin a new branch of its own. Actually, you can easily imagine

yourself as a member of such a group.  As the vocabulary of some began

to grow, imagine yourself not being able to understand the new word or

two. Confused you'd find yourself unable to respond appropriately. Now

imagine yourself as one of the apes with the growing vocabulary.  As you

spoke to the group you'd find that some responded appropriately while

others drew a blank. You'd find yourself gravitating towards those who

could grasp the meaning of the new words. Gradually those who could

communicate easily would coalesce into a new group and begin to grow

apart from the larger society.  A few friendlies would come along, even

though they could not understand the most spoken words, and some

of these go-alongs might even get to breed with the new group. 

Over tens of thousands of years the division would grow larger and

larger as the increasingly complex language facilitated the rapid advance

of technologies, eventually, the species "bridge" would break and the

parties could no longer breed. Homo sapiens would be on their way to

the future.