We still live in a mysterious world, with lots of unanswered questions and plenty of avenues of exploration open to anyone curious enough to pursue them!
We see avatar and see how far into the future he saw those animals and they had evolved these complicated neuronal cross species connections. Now if you believe in evolution, then you can't argue with that as a potential reality in the future. In a way, it does exist across species now in more trivial forms, including, if you will allow me, eye contact. I would offer to suggest that eye contact may actually be one of the first forms of cross species and even family. Birds, fish, all kinds of mammals... You can make eye contact and communicate with them if you have the patience. The more primitive the organism, the more patience is required to communicate with it -- if it can communicate.