Cyanobacteria: R-E-S-P-E-C-T

We owe cyanobacteria our respect. And they might deserve our fullest gratitude as well if it weren’t for one nasty trait.

For starters, if we are to believe that our elders deserve respect, cyanobacteria certainly qualify. They date back 3.5 billion years, almost to the earliest signs of life. But they are not only old. They are interesting, they seem uncomplicated, and they are powerful and successful. They are single-celled, though many live connected to each other in colonies and filaments. They are primitive; unlike the cells of younger species, they have no nucleus. And they have not only survived all this time; they have thrived. Their species number at least two thousand that have been described and at least twice that number in total. Most are blue-green—“cyan”—but their various pigments also account for the colors of pink flamingoes and the Red Sea.

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Cyanobacteria gave us oxygen—and continue to do so. For the first two billion years after the earth’s formation 4.5 billion years ago, the atmosphere contained almost no oxygen. But the blue-green pigment in cyanobacteria is a mix of green chlorophyll and a blue pigment both of which turn sunlight and carbon dioxide into sugary energy for the cell. Oxygen is the waste product—and early cyanobacteria produced so much of it for so long that it accumulated in the atmosphere and eventually supported larger, more complex cells, including ours.

Just as important, atmospheric oxygen spawned an ozone layer that reduced the lethal levels of the sun’s ultraviolet radiation. It’s that filtering that allowed early plant and animal life to finally move on to land after three billion years in the water.

Cyanobacteria made plants themselves possible by becoming part of them. Some other early bacteria engulfed cyanobacteria and then, because of cyanobacteria’s efficient energy production, turned them into one of the pieces of organic machinery enclosed within a plant’s cell. We see them today as the greenery of plants—the chloroplasts—that power them and keep them reaching for the sun.

Cyanobacteria are handy with another gas in addition to oxygen. They convert nitrogen in the atmosphere into a form that plants and animals need for such building blocks as proteins and DNA. Natural nitrogen fertilizer.

pond scum wikipedia


Cyanobacteria often go by the name of blue-green algae. But they’re not algae. Algae is an informal term for many water-borne organisms that contain  chlorophyll but lack stems, roots, or leaves. Seaweed is algae. Cyanobacteria are bacteria—simple cells, often strung together, without nuclei.

As for that one nasty trait, cyanobacteria can kill you. Especially in freshwater ponds and lakes, blooms of cyanobacteria looking like blue-green paint slicks may be toxic to nerve and liver systems, depending on the species. The poisons may work their way into the food chain, pets may eat them, water-skiers may absorb them. The result can be respiratory failure, Parkinson’s, ALS. Not often, but too often. Respect.

Reading about cyanobacteria on the Internet, you get a glimpse of a life-form from an inconceivably ancient world that is woven throughout the air, water, and soil of our own time. We are in their debt for the breath we take, the food we eat, for our living on solid ground.  We stand on their countless, tiny shoulders.

Is DNA Alive?

No, it’s not alive…mostly. The only sense in which a DNA molecule is a living thing is that it makes copies of itself, although it can’t even do that on its own. Otherwise, DNA fails all the tests: it doesn’t process anything in order to maintain its state, it doesn’t grow and develop, so it has no energized activity that starts or ends—in other words, it’s not born and it doesn’t die.

Somewhere along the line in reading general science I picked up the impression, even though I think I knew better, that DNA strands are alive. They are such vital keys to living organisms, and I read so many descriptions of what DNA does and of “selfish” genes, that although I knew they were blueprints of a sort, they came to seem like living blueprints.

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DNA and seed

One image that took shape in the back of my mind was that DNA was a kind of seed, and seeds, I thought, are alive. But no, seeds are not fully alive either. They are not active and, until they germinate, they don’t change or develop. (Another familiar item that may seem alive but that doesn’t meet all the criteria are viruses. Viruses are bundles of DNA that become active only when they are inside a cell, at which point they take over the cell and give us the flu.)

It shouldn’t be surprising that some familiar biological components do not, by themselves, meet all the criteria for the complex condition we call “being alive.” Still, surprised I was about DNA. Perhaps because we humans are so fully aware that we are alive, it is easy to think that there must be a fully living seed or even a soul at the root. It is almost more than we can imagine that the liveliness we feel is the product of a complexity of non-living parts. It’s an astounding thing.

The Voice In Our Head: Periscope Or Smoke-and-Mirrors?

Stream of consciousness is a common term for it. Mind wandering and daydreaming are others. These days, more narrowly, “self-talk” refers to our constructive or negative mental judgments of ourselves. “Default mode network,” from neurology, labels the closely interacting regions of the brain that kick in when it is not focused elsewhere.

There is a tension that runs through discussions about stream of consciousness. In science, the reality of any aspect of nature that is under study is acknowledged and respected. Psychologist and neurologists, despite controversies about it, extend such respect to stream of consciousness. On the other hand, the Buddhist or Eastern view of the mind is that the stream of consciousness, while real, is a detrimental spinoff of our psyche. It reinforces the entanglements of our ego with worldly concerns. The wise person will seek to quiet it or ignore it or seek complete release from it.

The tension here is not a disagreement or a debate exactly. It is more a dissonance that stems from the different aims of science and religion. Scientists, committed to objectivity, make judgments cautiously and narrowly. Religious teachings, on the other hand, offer a path towards peace of spirit, a path that invariably calls for the submission of the ego.

It’s no wonder that we read about the marvels of the human brain one day and the unhappiness of the wandering mind the next.

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I’m in the middle here. Our biological past is a foundational belief for me and I think that our stream of consciousness serves adaptive functions that can be understood largely in terms of evolution. But I also want to reduce my stress level and strengthen my sense of focus through meditation. The views of science and religion about stream of consciousness are not incompatible, but you don’t hear much about their common ground or a unified approach.

How could we find such a common ground? Probably in looking tolerantly at the ways in which stream of consciousness both serves us and hinders us. Probably by recognizing that it is difficult for most people to enjoy its advantages without also putting up with at least some of its disadvantages.

We can roughly gauge the advantages of stream of consciousness from noting the kinds of items in our own stream. Mine buzzes with flashbacks, flash-forwards, bits of script for conversations and letters to editors, and a mix of sunny and cloudy moods about myself—all of which I can see as beneficial much of the time in one way or another. But like most people’s, my stream sometimes fails badly to tell me what others are really thinking, worries needlessly about what probably won’t go wrong, and obsesses about what is unimportant. Stream of consciousness might be compared to a periscope through which we can fortunately see above the surface and around corners to what lies ahead, but which also captures fragmented and misleading pictures.

Sam Harris in Waking Up puts the spiritual case against stream of consciousness. We are “continuously spellbound by the conversation we are having with ourselves.” As both the speaker and listener in our heads, we create the illusion of the individual self. Harris adds, “We brood about the past and worry about the future. We continually seek to prop up and defend an egoic self that doesn’t exist.” Viewed this way, stream of consciousness is the voice of illusions, of smoke-and-mirrors. Still, no matter how we define self, humans like all other organisms need a steady flow of information, no matter how imperfect, to monitor the environment and process our complex social life. Harris, awake as he is, still writes, lectures, and engages with many people.

So I think a common ground between the spiritual and scientific approaches to stream of consciousness might essentially be the recognition that we live in three time frames, not one, and in many locations. These are of two different kinds, the sensory perceptions of the here and now, and the remembered and imagined past and future in other places. We need to process all of these not only unconsciously but through our stream of consciousness. As in so much else, balance between the here and now and other times and places seems a good goal.

I recall a simile—from the popular gestalt therapist, Fritz Perls?—that living solely in the moment can be like listening only to the note in the music that is sounding at the present instant.  Unless we’ve also heard the notes that lead up to that moment, there is no music. And, I would add, if we can hear only the past notes but cannot hear the note of the moment itself, the music can never be new.