I understand that this question may be perceived as a bit broad for this site, but I've decided to post it anyway. I figured that with the number of linguists, linguaphiles, and all-around language geeks on this site, I might get a rather intelligent (brief) answer pointing me to more detailed discussions on the subject.
It is my belief that one of the ways language evolves is similar to all other forms of evolution. Certain usages fall into and out of favor depending upon local necessity, and geographic separation can often lead to wide divergence in common languages (accents, sentence structure, etc.). One need only to look at the wide variations in English spoken in England, Australia, Canada, and the USA for proof of this divergence.
Clearly loan words and other factors have a strong influence on the evolution of a language, but I would like to set those aside for a different discussion.
I have long theorized that with the advent of mass media, and particularly the growth of the internet and social media, that language is now passed without the restrictions imposed by geographic separation. I think this should be a fairly self-evident statement, but as an example: If Hollywood movies are viewed world-wide, then American English and idioms should be spread world-wide to no small degree.
So, after that long-winded introduction. My question:
Is there any evidence that language (particularly English) is undergoing convergent evolution, where we are all beginning to speak more similarly to one another since the advent of mass media? Has this been a focus of study?
While the process is slightly different in the biological sense, I think that convergent evolution is an apt term here.