Chapter 7 - Are We Alone?

Chapter 7
        If Earthís future space travelers came to this place, they would declare it a Godforsaken wilderness. A trackless vista of cliffs and escarpments stretches to the horizon. Brown rock scorches under twin giant suns in a blood-red sky. The air is a thin gruel of sulfur dioxide, methane, and nitrogen. But thereís more here than meets the eye. In the pore space of the rocks, something is stirring.
        At a boundary layer with the deep mantle, mildly acidic water bubbles through the rock, driven by heat and pressure from the interior. Miles underground, microbes thrive in a rich brew of organics and dissolved minerals. They move by sensing magnetic fields and temperature gradients. Huge colonies begin to differentiate their function and metabolism to better use the available resources. Symbiotic behavior emerges.
        In the course of ceaseless and random genetic variation, some organisms develop the ability to vibrate their outer membrane and sense when it is perturbed. The timing of a return ultrasound wave acts as a primitive proximity sensor. This brand of microbes maintains the spacing to garner more resources so it rapidly dominates the colony.
        As the strategy becomes more successful, the organisms with the most powerful emission or most sensitive reception must deal with a cacophony of ultrasound signals. Some do this by tuning their vibrating membrane to a fixed frequency channel. Others learn to combine different inputs, moving beyond stimulus-response to a simple form of signal processing. The sonic champions gradually migrate to the center of the colony, where they can emit in synchrony and so increase their power and range.
        These profound changes donít happen overnight. There are tens of millions of years of experimentation and dead ends before individual organisms begin acting in concert. But once it happens, a positive feedback loop is set up that spurs even more experimentation.
        Something unexpected happens. The activity of the colony as a whole creates a low frequency sonic signal that travels easily through rock. Imperceptible to individual microbes, the hum is registered by the cooperative nexus at the heart of the colony. But there are other low frequency signals with more remote origins. Gradually, microbial colonies sense each other throughout the vast subterranean biosphere. The signals form a primitive network.
        All this would be invisible to a casual interstellar tourist. Awareness is too strong a word, too anthropocentric. At what point does reaction shade into intention, or signal processing shade into intelligence? We may not have enough distance from the buzz of our own thoughts to judge. But something interesting is happening here, and the planet, like the universe itself, is still young.

Chapter 7

Are We Alone?

Chapter 7 Vignette  Artwork  Content  Images  Back