Genesis for Non-Theists

Creation narratives are lively stories.  In the Bible, God creates the universe and earth in six days. In other traditions, creatures are dismembered, huge eggs hatch, birds create land. Even science’s own creation narrative starts with a Bang and once earth takes shape, the first organic molecules appear relatively quickly, within a billion years. 
 
But at that point the scientific story of life slows way down. Life remains at the stage of single cells for the next two billion years. What was happening to our smallest, oldest ancestors all that time? Why did it take so long to move beyond the stage of one-only? Was evolution on hold?
timeline

From “Oldest bacteria fossils” to “Multi-cellular eukaryotes” 2 billion years later, life on earth was single-celled.
(vector-clip-art.com)

What took so long was the creation of the building blocks for being alive. It’s a story with parallels to the first chapters of Genesis. The biblical sequence: plant life emerges on the third day, including “fruit trees bearing fruit in which is their seed,” followed over the next three days by creatures of the water, air, and land, including man and woman. A few verses later we read about the Garden of Eden and, symbolically, the beginnings of sex and death.

Here briefly is science’s version: life evolved from the simplest cells to cells with a nucleus that enclosed the protected “seed” of DNA. This change set in motion the end of one kind of immortality, the beginnings of sex and death, and the emergence of a new immortality.

The process was slow because the changes were huge.

LUCA
Like the Bible, science has a name for our first ancestor. LUCA, our “last universal common ancestor,” was a single-celled organism, a kind of bacterium, from which all life on earth is descended. Inside LUCA was a floating coil of DNA, sections of which have been passed down to every living thing.
Prokaryote

Our common ancestor, a cell with DNA but no nucleus
(shmoop.com)

LUCA reproduced simply by dividing, with one set of genes in each new cell. The new cells were identical, a long line of Adam clones without an Eve.

LUCA’s membrane enclosed only watery liquid and the genes. Gradually LUCA’s descendants “ate” and absorbed other bacteria. Some of these bacteria turned into the nucleus of the cell that absorbed them. They became the container for the cell’s genes. Such cells advanced from  prokaryotes (before a nucleus) to eukaryotes (a true nucleus, and pronounced “you carry oats”). The nucleus was a seed, a seed that provided the DNA with a chemical environment of its own and helped grow more complex DNA and much larger cells.
Sex, Death…
cell

Cells get a nucleus–and more.
(biogeonerd.blogspot.com)

Early cells were, in their own way, immortal. The genes in both prokaryotes and early eukaryotes would reproduce and then the cell would split into two identical cells, as bacteria still do. Did such cells die? Eventually, but only from accident or the environment. In this Eden, cells did not get older. They became their own offspring and could theoretically live forever.

Eukaryotes, however, found a new way to reproduce. One would rub up against another eukaryote and portions of their DNA sets would be inserted into the other—the original sex act. With this exchange of DNA, genetic variation sped up, at last. So did natural selection.
 
In the next step, sex became specialized. As some early organisms became multi-celled, such as algae, they reproduced not by division of the whole parent organism but, as with us, by means of specialized germ cells (not the disease kind of germ but the creative kind, as in the “germ of an idea”).
No longer was the parent reincarnated in a clone, as in bacteria. It was left behind, and it aged and died. As in Genesis, the co-mingling of different living things brought sex and death. Cellular life moved beyond Eden.
 
…and Immortality
So we have lost the immortality that the prokaryotes enjoyed. But we have found it in another, more complex form. Our immortality runs through the genetic line of our children and other blood  relatives. It turns out that it is not the body, the soma, that is the crucial package. It is the germ cells that carry the DNA forward. 
 
But is this an adequate and satisfying idea for us humans who dream of living forever? Is the continuity of DNA a meaningful form of immortality? Here is one answer from Harvard biology professor George Wald, in his 1970 lecture on “The Origins of Death.”
 
We already have immortality, but in the wrong place. We have it in the germ plasm; we want it in the soma, in the body. We have fallen in love with the body. That’s that thing that looks back at us from the mirror. That’s the repository of that lovely identity that you keep chasing all your life. And as for that potentially immortal germ plasm, where that is one hundred years, one thousand years, ten thousand years hence, hardly interests us.
 
I used to think that way, too, but I don’t any longer. You see, every creature alive on the earth today represents an unbroken line of life that stretches back to the first primitive organisms to appear on this planet; that is about three billion years. That really is immortality. For if the line of life had ever been broken, how could we be here? All that time, our germ plasm has been living the life of those single celled creatures, the protozoa, reproducing by simple division, and occasionally going through the process of syngamy — the fusion of two cells to form one — in the act of sexual reproduction. All that time, that germ plasm has been making bodies and casting them off in the act of dying. If the germ plasm wants to swim in the ocean, it makes itself a fish; if the germ plasm wants to fly in the air, it makes itself a bird. If it wants to go to Harvard, it makes itself a man. The strangest thing of all is that the germ plasm that we carry around within us has done all those things. …
I, too, used to think that we had our immortality in the wrong place, but I don’t think so any longer. I think it’s in the right place. I think that is the only kind of immortality worth having — and we have it.

Darwin’s Dark Vision: “Ten Thousand Sharp Wedges”

Darwin has gotten to me. The third chapter of On the Origin of Species has changed how I look at nature. The name of the chapter sounds quaint at first: The Struggle for Existence. But it is an apt name for a dark, violent vision.

For Darwin, the central reason that life is a struggle is the numbers. Seeds, larvae, eggs, babies—most living things reproduce in big numbers, every year. We modern humans with our small families and our one or two pets don’t think of reproduction on that scale.

But, as Darwin writes, we should not forget that in truth “every single organic being around us may be said to be striving to the utmost to increase in numbers; that each lives by a struggle at some period of its life; that heavy destruction inevitably falls either on the young or the old…Lighten any check, mitigate the destruction ever so little, and the number of the species will almost instantaneously increase to any amount.”

And then this astonishing simile: “The face of Nature may be compared to a yielding surface, with ten thousand sharp wedges packed close together and driven inwards by incessant blows, sometimes one wedge being struck, and then another with greater force.”

purple loosestrife

The invasive purple loosestrife. Each plant produces one million seeds each year, every year. (fenton.patch.com)

We don’t notice the intensity of this competition in part because plant life takes place in slow motion. Darwin studied what lived and what died; he counted the seedlings in a patch of his yard and saw that most did not survive the struggle against competing weeds and insects. “We behold the face of nature bright with gladness, we often see superabundance of food; we do not see, or we forget, that the birds which are idly singing round us mostly live on insects or seeds, and are thus constantly destroying life; or we forget how largely these songsters, or their eggs, or their nestlings, are destroyed by birds and beasts of prey; we do not always bear in mind, that though food may be now superabundant, it is not so at all seasons of each recurring year.”

gulls

Whether an animal is sustaining itself or is destroying other life is a matter of point of view.  (telegraph.co.uk)

Although he uses the word “competition” to point to one obstruction or another, Darwin doesn’t find that word sweeping enough. And indeed today, for us, the term usually refers to what goes on between two individuals or teams or companies and the like. Struggle, however, points to competition in all directions at once—to the competition between a living thing and others of its own species, competition with other species, struggle against disease, against climate. It is the intensity of this struggle between the numbers of one’s offspring pitched against the strength of the adversaries that makes natural selection so effective. Any advantage, no matter how small, is big.

At the chapter’s end, the vision of the struggle slides over to “war”—along with a dubious consolation. “When we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.”

roadside plants

Along a roadside, the slow-motion war goes on. (nps.gov)

Where I live, the plants and insects look vigorous and healthy as always, but I see them differently now. In the small overgrown zones between suburban backyards and along roads, I used to see beauty, vitality, and tranquility. That is what we are expected to see in nature, after all. But now I look first at what plants are the greatest in number; they are, at the moment, the winners. They are the best adapted, putting other plants out of business in slow motion, and producing the most variations that might make their offspring even fitter.

Humans are similarly primed for struggle and competition of all kinds. Even here in suburbia, we are all alert to shortages or price increases in food and fuel, to drought and flood, to violence and car crashes, to drugs and diseases, to potential enemies in the neighborhood and in the world–“incessant blows” on the “sharp wedges” that are driven in on the “yielding surface” of our lives.

Before Heart Surgery

Next week a surgeon will remove my aortic heart valve and sew in a new one. It’s a brutal thing, this fact that someone will carve into my chest and carve out a piece of my heart. But it’s necessary to fix the plumbing. My heart pumps blood into my arteries through a valve that is then supposed to close to keep the blood from flowing back into the pump. But the valve leaks, half of what’s pumped out spills back in, the heart works harder to make up the deficit, and I take another nap.

heart

(science.nationalgeographic.com)

The body is all about circulation—of blood, air, chemicals, even electricity. (Because of the leaky valve, the electric pulses through my heart can act up.) We don’t picture circulation very readily—the diagrams are tedious. But circulation, cycles, circles are the shape of continuity at all levels of nature. And sometimes it takes only a small glitch–a leak, an obstruction, an intrusion—to bring circulation almost to a halt.

Some days during the last few weeks I’ve felt very nervous about the surgery, other days not much. I’m not sure why. I expected that as it came closer, I would become more anxious, but that’s not happening. There are so many strands that wax and wane in anyone’s state of mind—including, in my case now, confidence about the procedure; anxiety about the assault; feeling physically run-down some days from the meds as well as the leaky valve; the steady pleasure of spouse, family, friends; this blog. Many strands.

So it’s not just the blood that is circulating and the electrical impulses that are flowing. My moods and their strands flow as well, even when they leak backward and things seem better and then worse.