So you are agreeing with creation? I agree languages have common origins. It is also interesting that older languages, like Classical Greek, Sanskrit, and Latin in the west, are much more complex, that modern langagues. English is a good example of a language that has been dummied down. No gender, or cases, simpler languages and verbal patterns. Hebrew has an extremely complicated verbal system.
So, it sounds to me like you are promoting devolution. In other words, God created people, language in a perfect form, and since the fall, everything is just falling apart. Change within species is always for the worst. Mutations are fatal, or at least unhelpful. There really is no scientific mechanism for change that could account for any of the major deviations or differences between species, because mutations, no matter how much time, simply do not create an eye, a woodpeckers structured brain, a liver, or why fish have gills and mammals and reptiles have lungs!
But, I digress.