Lets start with language then:
http://www.ancientscripts.com
The oldest known written languages would be ancient Egyptian(cuneiform) and Sumerian. The time of these writings began around 3200 BC.
The oldest surviving written languages would be an old form of Greek and/or Chinese, coming in around 1500 BC.
But the fact that we can identify and date these languages doesn`t indicate that this is when they appeared. It is obvious that many languages were not written down. For instance, there is mention in ancient writings about other cultures with their own languages.
" To take one interesting case, the Albanian language (spoken north of Greece) was not written down until about the 15th century AD, yet Ptolemy mentions the people in the first century BC.* The linguistic and archaeological evidence suggests that Albanians were a distinct people for even longer than that. So Albanian has probably existed for several millennia, but has only been written down for 500 years."
There are also languages that evolved from other languages, such as french and Spanish splitting off from Latin. English now has quite a few languages that has been borrowed from as we know.
As for when humans had the capacity for having a full language, we can never know. Linguistics assume that by 100,000 BC we had more than enough capacity to communicate because by that time we were living in groups and communities, which would neccessitate communication. Yes, this is only an assumption.
There is roughly 200 major languages in the world today, with over a million speakers of them. There is thousands and thousands of proto languages, the total languages researchable is somewhere around 5000. We know languages evolved as speakers of one language were isolated to develop whole new languages on their own.
Before I go on, let`s look at this chart of written language emergence through time:
http://www.ancientscripts.com/ws_timeline.html
Now ,even though we know the language could not have been developed and then put in written form at one instant, for arguement sake we can compare it to the Bible right now.
Judging by our language knowledge, we see that the Babel story could not have taken place any earlier than about 3200 BC. We see only two written languages at this point in time, Ancient Egyptian (cuneiform) and sumerian.
We also note that many languages emerged very much later, which ruins the idea that all these languages were suddenly positioned after the Babel incident, If we decide to not accept a language as existing until it was written.
If we decide that all these languages came into being at 3200 BC, only being written down at different times, then we forget a few things. One being that these were presumably all the same people, there would be no reason for one language to be written down immediately while others were not.
So let`s look at the Christian Timeline, which was based on the same book that "accurately" tells us pages and pages of who begat whom:
http://www.ouryouthgroup.com/devo/timeline.html
Tower of Babel 2144 BC (other says as late as 2175BC)
Some others:
http://www.bible-history.com/rome/RomeTimeline__Biblical_History.htm
http://www.bible-history.com/rome/RomeTimeline__Biblical_History.htm
So there is some discrepancy in the timelines people have developed from the bible. I read they arrive at these numbers by counting the generations which are laid out in the book, so some variation is understandable.
So where are we now? Now what happens is you say the bible isn`t accurate enough to get a timeline from it with any accuracy?
Sorry to be so winded, I don`t cater to the Babel story, see. It was a guess of ancient man who was faced with the question of "where did all the languages and races come from then?".