Could you tell me what studies suggest that brain evolution is occurring at this moment?
Aside from the fact that we cannot rule out the possibility that brain evolution is occurring, how could we study it? Evolution of the human brain would have to occur so slowly that we could not perceive or research it.
Also, that is the reason we cannot sensibly say anything about the future of our cognitive abilities [aside from the fact that we might lose them due to radiation, ingested poison and other environmental pollution.. :-)] : how could we say anything about the future of a process of which we a. don't know if it is even occurring, and b. don't have the faintest idea what it is influenced by.
I think your students may simply never have learned to write well, or be too lazy... ;-)