Tuesday, October 25, 2011

On The New Meaning of "Human"

I have a "gut feeling about this" is a common utterance amongst some people.

Once upon a time we would chuckle or giggle at the question: "Is a 'gut feeling' a signal from your microbes?"

But more and more a "yes" answer to that question is looking neither fully impossible nor fully improbable, according to experts in this field of human-microbe symbiosis:
Scientists originally expected that the communication between animals and their symbiotic bacteria would form its own molecular language. But McFall-Ngai, an expert on animal-microbe symbiosis, says that she and other scientists have instead found beneficial relationships involving some of the same chemical messages that had been discovered previously in pathogens. Many bacterial products that had been termed “virulence factors” or “toxins” turn out to not be inherently offensive signals; they are just part of the conversation between microbe and host. The difference between our interaction with harmful and helpful bacteria, she says, is not so much like separate languages as it is a change in tone: “It’s the difference between an argument and a civil conversation.” We are in constant communication with our microbes, and the messages are broadcast throughout the human body.
(The Body Politic, Seed Magazine, emphasis added). The Dredd Blog System has been looking into the human-microbe symbiosis for a while, for example, see The Undiscovered Side of Science and Life, Hypothesis: Microbes Generate Toxins of Power, Hypothesis: Microbes Generate Toxins of Power - 2, and Weekend Rebel Science Excursion.

It is even beginning to look more and more like we are simply not "human" in the sense we have always thought we were:
After all, our cells carry an ancient stamp of symbiosis in the form of mitochondria. These energy-producing organelles are the vestiges of
symbiotic bacteria that migrated into cells long ago. Even those parts of us we consider human are part bacterial. “In some ways, we’re an amalgam and a continuously evolving collective,” Relman says.

... life as we know it is built upon microbes, whether we look in the deepest oceans or our own intestines. We once had the luxury of ignoring the diminutive members of our bodies and other ecosystems. Now the blinders are off.
(ibid, emphasis added). Yes, "Our bodies harbor 100 trillion bacterial cells, outnumbering our human cells 10 to one", so we need to rethink "environment", "mother nature", and "ecosystem" in terms of humans being separate from them, because we are decidedly not separate from them.

We defined human sanity more in accord with the revelations of that recent science in On The Definition of Sanity, and also pointed out that we reached The Peak of Sanity when we abandoned the reality of our nature to become our own worst enemy by going in the direction of Ecocide.

The next post in this series is here.