If there was an ancient common language among humanity some clues should be remain. Most of the common words could change or mix through the ages, but maybe, just maybe we could find some clues in several nowadays words. For example, let's consider the word "heart". This word and concept is so important for humanity that sure it deserves some study. I'm pretty sure that you guys can do this much better than me, I just try to help with my two cents.
In English, the word "Heart" comes from German "Herz", but another form for the same is "Kern", that also means "Core".
And this is a very interesting root. We see that in Russian, "siertse"(сердце) also comes from german "Herz".
But once again we observe that "kern" german word exists in russian as "kern" (керн).
With the Latin root "cor", other languages' words for heart are obvious: "corazón" in Spanish, "coeur" in French or "coure" in Italian, giving just some examples. But we observe something really interesting because we can find the same root in irish, o even in japanese!
"Croí" in Irish, and "Kokoro" in Japanese.
This is fun
What do you think?