How Did Life Emerge from Stuff?

How, specifically, is a living thing different from lifeless chemistry? Once we can answer that question, we can ask the next one: How did the first emerge from the second?

Jeremy Sherman’s new book, Neither Ghost Nor Machine: The Emergence and Nature of Selves explains recent thinking on these questions, especially the work of neuroscientist Terrence Deacon. In this post and the next, I’ll summarize highlights of the book.

Sherman emphasizes this difference between living and non-living things: living things have purpose and non-living entities do not. Purpose here has little to do with what we mean when we talk about a person’s “sense of purpose” and it has nothing to do with divine intention. It refers instead to biological processes aimed at maintaining the state of being alive. The heart’s purpose—its function—is to pump blood. The purpose of a leaf is to produce food for the plant. We take for granted that bodies and their parts serve functions and yet it feels strange at first to identify purpose itself as a distinguishing feature of all organisms.

campfire (shutterstock.com)

shutterstock.com

Non-living stuff has no such purpose or aim or sustaining function. A fire in the fireplace burns and gives off heat and carbon and other gasses and then the fire, without more fuel, goes out. Sherman writes, “Most chemical reactions yield a proliferation of molecular products” but such reactions soon peter out. The reactions in living things, on the other hand, don’t fizzle out so easily. Through their biochemistry, living things “are self-regenerative in two senses: they maintain their own existence, and they produce new selves” (9).

Produce new selves? Sherman (like many biologists) refers to organisms as selves. Like purpose, applying self to an organism calls attention to the ways that even a bacterium, like a human, works to find food, defend its-self, repair its-self, and make more selves. Inanimate things don’t act as selves. Left alone long enough, anything inanimate will become disorganized and break down. An ice cube left on a counter will melt and then evaporate, its molecules finally dispersing into the air. And with selves, we can say that something—fuel, information, lower temperature—is good or bad or useful or significant for it. In contrast, as Sherman writes, “Nothing is ever functional, significant, or adaptive for sodium chloride, snowflakes, mountains, fried chicken, or even computers” (25).

But what about natural selection? Didn’t Darwin’s work explain how living things evolve? Yes, but natural selection doesn’t explain the first appearance of the selves that do the evolving. “To claim that natural selection explains purpose is like claiming that erosion explains mountains. Erosion…explains how mountains are passively sculpted, but not what’s sculpted. Likewise, natural selection explains how populations of selves are passively sculpted…[as] some lineages produce more offspring than others, but not how selves arise in the first place.” (9).

So, here’s the mystery: what kinds of inanimate chemical reactions might have come together as stepping-stones towards purposeful, self-regenerative selves? I’ll summarize Sherman’s answers in my next post.

“Damn it, it’s MY Body That’s at Stake”: Autonomy, Sociality, and Imperfect Choices

My family were swapping medical grievances one evening: flawed diagnoses, unwanted side effects, useless procedures. “Damn it, it’s my body that’s at stake” was one protest. As a species, we are quick to feel protective of more than just our health. Insert “my life,” “my rights,” “my money,” “my freedom.” When alarmed, we rush to defend our autonomy from relatives, employers, government, banks. Don’t tread on me.

But we work the other side of this interaction too. We uphold—because we benefit from— social codes and expectations against would-be rebels. “Don’t forget to invite that cousin you don’t like. Family first.” “You’re going to wear that?” “Showing up is eighty percent of the job.”

We carry both the autonomous nonconformist and the social enforcer inside us. The roles take different forms in different cultures, but they are in our genes. Our autonomy is our expectation that we can exist independently from others, that we can make our own decisions, solve problems ourselves. But that doesn’t mean we expect to go it alone. We are groupies, as contradictory as that seems to autonomy. The biological term is sociality. Sociality doesn’t refer to being sociable or friendly. It refers to the inherited tendency to form groups, sometimes highly organized groups. Social ants work for the queen, bees signal each other how to get to honey, wolves hunt in packs. Stronger together.

But as inherited traits, autonomy and sociality aren’t so perfect together. Most species inherit more of one than the other. Cats go solo, while ants hatch already equipped for their roles as workers, soldiers, or queens. The blessing and the curse for humans is that we have high levels of both. It feels right to us to decide what is best for our self—at the same time that we’re reluctant to risk our social support. The result is ambivalence. “Should I take the statin/invite the cousin/change my shirt/get my lazy self to work?”

Here, says sociobiologist Edward O. Wilson, is our spiritual turmoil and our humanity. When our loyalty to our clan, party, religion or other group clashes with our sense of our individual well-being, we feel angry, sad, confused, frightened, or betrayed. Near the close of the fifth chapter of Sociobiology (2000 edition), Wilson summarizes the dilemma with a passage from the Bhagavad Gita, the Hindu epic from 300 B.C. E. Here, the god Krishna steers the chariot of the reluctant prince Arjuna to an impending battle in which Arjuna’s relatives and closest friends will be fighting not with Arjuna but for the other side. Wilson writes about

ambivalence as a way of life in social creatures. Like Arjuna faltering on the Field of Righteousness, the individual is forced to make imperfect choices based on irreconcilable loyalties—between the “rights” and “duties” of self and those of family, tribe, and other units of selection, each of which evolves its own code of honor. No wonder the human spirit is in constant turmoil. Arjuna agonized, “Restless is the mind, O Krishna, turbulent, forceful, and stubborn.”

Krishna-Arjuna-battle (hinduhumanrights.info)

Arjuna hesitates on the Field of Righteousness (hinduhumanrights.info)

I first read that passage years ago but it comes back to me when I hear protests and arguments. We are Arjuna, come to the field of life with two strengths that work to our advantage but also get in each other’s way. I understand people better, myself included, when I listen for the rumbling, ageless tension of self versus group beneath our “imperfect choices” and “irreconcilable loyalties.”

Breath: Divine Gas In a Smart Body

We use the word breath most often to refer to the air we pull in to and pump out of our lungs (or to the action of doing so) as in “Take a deep breath.” But we also give the same word loftier qualities in phrases such as “the breath of life” and in practices like yoga that emphasize breath awareness as a source of health and peace. Other traditions and languages have similar words for breath in both these ordinary and spiritual senses, such as Latin spiritus, Hebrew ruach, and Chinese qi.

breath spirit (soundofheart.org)

soundofheart.org

But what about the breathing body itself? Unless we are wheezing or short of breath and a doctor checks us out, we usually take the smooth coordination of our lungs, diaphragm, membranes, blood cells, as unremarkable compared to the loftier significance of breath that we might hear about in yoga class or worship service.

We might refocus our wonderment for a moment. The air is, when you come down to it, just a mix of gasses, but our body’s ingenious respiration of them is something to appreciate.

We breathe in air because, as we know, it contains one gas that we must have: oxygen. Less familiar, though, is the step-down system that has evolved to make the most of the fact that, like all gasses, oxygen spreads out from wherever it is most densely packed to where it is less so. Thanks to the step-down process and our blood stream, we move oxygen from the air outside of us to everywhere it has to go inside us, which is to our several trillion—that’s 000,000,000,000—cells.

Why oxygen? Its electrons are arranged in such a way that it interacts eagerly and often with other elements. It’s a potent extrovert. Our cells may get their nourishment from the food molecules they take in but not unless they also have oxygen handy to break the food molecules down. That would be like our eating dinner without having any stomach acid to digest it. No nourishment. Without oxygen, cells go hungry.

But a little oxygen goes a long way. That helps make the step-down process possible. The numbers surprised me. For starters, only about twenty percent of the air that we breathe is oxygen. The rest is nitrogen and a percent or two of other gasses. And of that oxygen that we do take into our lungs, we actually use only about a quarter of it. The rest goes out again when we exhale.

Once it is in our lungs, oxygen must get across the thin lung membrane to the blood stream that will move it around the body. The oxygen in the lung is much denser than whatever oxygen is left in the blood that is returning from the cells through the veins. So the new oxygen spreads easily across the membrane—stepping down—to the oxygen-depleted blood where it hooks up with empty hemoglobin molecules in the blood cells.

As this convoy of oxygenated blood flows near, say, our fingers, the oxygen detaches from the hemoglobin, steps down across the membrane of the cell itself (because there is less oxygen inside), and goes to work on the food particles.

In the process, extrovert that it is, oxygen combines with the unusable carbon dioxide, crosses the cell membrane back out to some empty passing hemoglobin, gets off at the lungs, and then back out to air. Like taking the empty bus back home at the end of a long day.

I argue for the wonderment of a distribution system that pulls in air-borne oxygen in an endless rhythm and is arranged so that the oxygen disperses itself across strategic membranes and loads itself on to the blood for transport to a million million cells that it will help nourish, after which it returns the way it came in. Our stunning respiration makes oxygen look good—even divine.