Here's a fascinating TED talk by Stefano Mancuso, a founder of the study of plant 'neurobiology', which explores how plants communicate, or "signal," with each other, using a complex internal analysis system to find nutrients, spread their species and even defend themselves against predators.
Watching this presentation prompts a number of questions for me. If consciousness is 'simply' an emergent phenomenon of a network of neurons, is it possible that other networks (roots, mycelia, even the Internet) could be self-aware too? Are we deceived mainly by the static nature of plants (or at least, their less noticeable movement) more than any other factor in thinking of them as vegetative? And once again, I am reminded of Dennis McKenna's psychedelic experience under the influence of ayahuasca (as told by Daniel Pinchbeck in his excellent book, Breaking Open the Head):
When Dennis McKenna, Terence's botanist brother, drank ayahuasca with the Uniao do Vegetal, a Brazilian syncretic religion that uses ayahuasca as its sacrament, he was turned into a sentient water molecule in the jungle soil, pulled up through a vine's roots to experience the miraculous molecular processes of photosynthesis in its leaves. "Somehow I understood - though no words were involved - that the Banisteriopsis vine was the embodiment of the plant intelligence that embraced and covered the earth," he recalled. At the end of his vision, a voice told him, "You monkeys only think you're running things."
Observant readers would have noted that McKenna's monkey line is the footer to my comments here on TDG. Some have assumed previously that it's meant as a moderator tagline about who is in charge here on the site, but in fact it's there simply as a reminder against anthropocentric hubris and assuming too much about our current state of knowledge. Will we have a completely different outlook (and relationship) with plants in two thousand years time? And if we find that plants are sentient, where does that leave vegans?