This post was a result of a Simon Greenhill article:
“Lexomics” – Breaking the language barrier
The trouble with “lexomics” is, as some of the commenters on the Nature article pointed out, is that the language evolution process is Lamarckian, not Darwinian; it’s driven, not followed.
If I was a lithping king, I could make all my thubjects lithp without too much trouble.
The other major problem is that there aren’t any fossils*. All the ancestors are hypothetical proto-languages.
If you take all the most common characteristics of an existing clade (or as many as you can find) and distill them down to the lowest common denominators, you’ll end up with a ‘proto-language’.
But you can’t be at all sure that major characteristics of the original ancestral language have not been entirely lost, or preserved in only a minority of the existing remnant languages. (Which you ignored, just because they were a minority).
Then, to trace the ‘descendents’ from this hypothetical language is absurd.
Even then, though, I hope some of the newer generation of linguists (you, Simon? – please)can use the mechanical/statistical techniques used by geneticists to resolve some major ‘language family tree’ problems, like the star-like pattern of supposed descendents from proto-Austronesian and proto-Oceanic.
*Except where we have surviving scripts. But it was pointed out a long time ago that if the Comparative Method was used, retrospectively, on the Romance languages, the resulting proto-language would NOT be Latin.