system
Given the following post, respond as if you're commenting on Reddit:
human
Is it likely that some of the larger language families have a common ancestor?

I was thinking about how dissimilar for example various Indo-European languages are, and that the further you go back in the family tree, towards proto-* languages, the harder it is for linguists to say with certainty that language A is related with language B and so on.

So, with that in mind, is it likely that some of the larger families have a common ancestor, but that divergence happened so long ago that there are virtually no similarities between the families any more? I was thinking specifically about the Indo-European and the Turkic families, seeing as how they may have originated in roughly the same region, but also any other groups.
gpt
It's within the realm of possibility that some of our current top-level families might be related, but to say it's even *likely* is a bit too strong of a statement. You need at least the barest minimum of evidence to suggest that, and we don't have it.

An important thing to keep in mind is that "they may have originated in roughly the same region" is *not* an argument for genetic descent from a protolanguage. For that you need the comparative method. You assemble lists of words you think are related, and find regular correspondences, e.g. Latin **d***ecem* and English **t***en*, Latin **d***ens* and English **t***ooth*, etc. "They look similar" isn't an argument: **d***ies* and **d***ay* don't cut it, for instance--they reconstruct to two different IE roots, one with *d* and the other with *dh*. You need a lot of these correspondences to establish genetic descent from a common ancestor, and the evidence simply isn't there for Turkic and IE.