Friday, January 21, 2011

Everybody's Talkin'


Communication processes, whether signaling or responding to signals, are most everywhere that life is. For example, plants seem to have their own form of internet:
Ren Sen Zeng and colleagues at South China Agricultural University in Guangzhou, grew pairs of tomato plants in pots. The team allowed some pairs to form mycorrhizal networks between their roots. Plants connected this way can exchange nutrients and water, staving off the effects of drought. But Zeng wanted to know if the networks had any other function.

The team sprayed one plant in each pair with Alternaria solani, a fungus which causes early blight. Sixty-five hours later, they infected the second plant and observed how well it coped.

Plants sharing a mycorrhizal network were less likely to develop the blight, and when they did, symptoms were milder. They were also more likely to activate defensive genes and enzymes (PLoS One, DOI: 10.1371/journal.pone.0013324).

The first plant was signalling to its neighbour, Zeng says, and he has dubbed mycorrhizae "the internet of plant communities".
Why should we be surprised, then, if plants have intelligence, too?


Many of us know that animals communicate, but we might not appreciate the diversity of information that such communications can convey. For example, according to one researcher, the chirps and calls of American prairie dogs are actually a very sophisticated form of communication:
During his analysis, [Northern Arizona University researcher Con] Slobodchikoff noticed something: Even though the human call was consistently different from the other calls, there was still significant variation between the individual human calls. He began to wonder whether the little rodents could possibly be describing their predators — not just differentiating hawk from human, but actually saying something about the particular human or coyote or hawk that was approaching.

So he devised a test. He had four (human) volunteers walk through a prairie dog village, and he dressed all the humans exactly the same — except for their shirts. Each volunteer walked through the community four times: once in a blue shirt, once in a yellow, once in green and once in gray.

He found, to his delight, that the calls broke down into groups based on the color of the volunteer's shirt. "I was astounded," says Slobodchikoff. But what astounded him even more, was that further analysis revealed that the calls also clustered based on other characteristics, like the height of the human. "Essentially they were saying, 'Here comes the tall human in the blue,' versus, 'Here comes the short human in the yellow,' " says Slobodchikoff.
The video below has Slobodchikoff talking about prairie dog communication as true language:


Human beings, of course, are capable of true language. Perhaps the best account of how human language developed is put forth by W. Tecumseh Fitch:
[Charles] Darwin's model for language evolution, "musical protolanguage," suitably updated, provides a compelling fit to both the phenomenology of modern music and language, and to a wealth of comparative data. By placing vocal control at the centre of his model, Darwin availed himself of the rich comparative database of other species who have independently evolved complex vocal imitation, and he thus explains two of the features of human language that set if off most sharply from nonhuman primate communication systems: vocal learning and cultural transmission. The biggest missing piece in Darwin's model, as I see it, is a reasonable explanation of phrasal semantics (and the aspects of syntax that go with it), but this gap was filled by Jespersen by 1922. Together, these hypotheses provide one of the leading models of language evolution available today (for an enthusiastic book-length exploration see Mithen, 2005), and one that has been repeatedly re-discovered by later scholars (e.g., Brown, 2000; Livingstone, 1973; Richman, 1993). While many aspects of what has now become a family of models remain to be explored empirically (the issues surrounding sexual, kin and group-selection remain particularly unclear), this is a model worthy of detailed consideration and elaboration today. Most importantly, Darwin's model makes numerous testable empirical predictions (for example about the partially overlapping nature of the brain mechanisms underlying music and spoken language, and their genetic basis) that can be answered in the coming decades.
Human language, explained as an evolved capability, demonstrates the continuity and connection of homo sapiens with all other life forms on Earth. Indeed, in both language and intelligence, life forms seem to lie upon a continuum; as far as I can tell, there's no radical break between us and the rest of life on our planet. What's more, this seems like a good thing to me.

I don't like the suggestion, often voiced in religious teachings, that animals and plants exist specifically for the benefit and enjoyment of human beings. Plant and animal communication argues against this viewpoint.

Another, related suggestion also voiced in religious teaching is that human beings are caretakers and stewards of the world. Sounds benign, right? Sounds like the resulting actions would be generally good: care and respect for animals and plants, responsible use of energy and food, lower-harm disposal of waste.

Yet, historically we have never been unable to find reasons to use our status as caretakers and stewards to advance our own interests alone. The caretaker/steward perspective is horribly anthropocentric and arrogant. It allows us to walk into any home we want, whenever we want.

If we fancy ourselves moral and we actually care about living things, we can do a better job of codifying the limits of our power with regard to plants and animals. We can, if we like, just say "fuck nature" and do as we please. That's certainly an option and perhaps a tick better than being killing caretakers.

2 comments:

  1. please pick the jets to loose to the steelers.

    thank you

    also, i would appreciate if you would predict the steelers score between 30-40 points.

    thanks again

    ReplyDelete
  2. It's "lose," not "loose."

    The Jets will lose the game.

    The Jets played fast and loose with the rules of both civility and football in the 2010 season.

    Anyway, I hope they win this weekend. But I'm not optimistic, as I explain in my recent predictions post.

    ReplyDelete

Feel free to comment if you have something substantial and substantiated to say.