All language groups are equally ancient. It is not as though one group of humans was speaking and another group of humans was mute. Nor is it as though one group of languages popped up spontaneously. For example, Modern English is descended from Old English, which is descended from West Germanic, which is descended from Proto-Germanic, which in turn is descended from Indo-European, which is descended from some earlier proto-Indo-European, which is descended from some more ancient form. Some linguists go back even further and try to derive all languages from a proto-World-Speak, the linguistic equivalent of mitochondrial Eve.

In fact, language groups are very much like population groups. All of the Indo-European language family share similarities, just as all the members of a genetic family share similarities. The sister languages within each daughter group, such as Romance (French, Italian, Spanish, Romanian, etc.), Germanic (English, German, Dutch, Swedish, Gothic, etc.), Slavic (Polish, Russian, Czech, Serbian, etc.), Celtic (Irish, Welsh, Breton, etc.) share more similarities…like sharing more genetic markers. And language cousins, like English and Russian, share more similarities than English and Chinese, which are totally unrelated. Moreover, languages change or mutate over time (so Old English is incomprehensible to a speaker of Modern English), just as genetic markers change or mutate over time.

For those more interested in the movement and spread of linguistic features and their distribution over the globe, particularly with reference to the movement of peoples (as languages only move only as a function of the movement of people who speak them), I highly recommend Linguistic Diversity in Space and Time (University of Chicago Press, 1992) by linguist Johanna Nichols.

It is wonderful and informative to see how the spread of linguistic types closely parallels that of the spread of genetic types. For example, both linguistics and genetics point to a circum-Pacific Asiatic homeland for the peoples who populated the New World. The parallels between linguistics and genetics are astounding. The one complements and corroborates the other.