New Thinking About the Origin of Life (1): Purposes and Selves

How does a living thing differ from a lifeless one? And how might those living characteristics have emerged from the lifeless matter that preceded them?

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

Sherman is emphatic about one particular difference between living and non-living things: all living things have purpose, non-living entities do not. Purpose here has little to do with 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. For example, 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 all their parts serve functions and yet it may feel strange at first to identify purpose itself as a defining feature of all organisms.

campfire (shutterstock.com)

shutterstock.com

Non-living stuff, on the other hand, has no such purpose or aim or sustaining function. A fire in the fireplace burns and gives off heat and carbon and other gasses, after which 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).

New selves? Sherman, following Deacon, refers to organisms as selves. Applying self to an organism calls attention to the ways that even a bacterium as well as a human works to find food, defend its self, repair its self, and make more selves. Inanimate things aren’t 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.

A related difference between selves and inanimate things is that with selves, we can say that something—fuel, information, a change in temperature—is good or bad or useful or significant for it. But for inanimate things, as Sherman puts it, “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 fails to explain the first appearance of all those 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, the question: what kinds of inanimate chemical reactions might have come together as stepping-stones towards purposeful, self-regenerative selves? Until now, that question has been explored in terms of possible ingredients. Chemical stews, viruses, RNA molecules, an iron-and-sulfur world have been among the candidates for starting points. But Terrence Deacon has asked instead what kinds of reactions, regardless of their ingredients, could sustain themselves long enough to postpone the terminal fizzle?

His answer, in the abstract, is that you need not one but two reactions, each of which constrains the other before it burns out. I’ll explain in my next post.

Forgiveness and the Second Law of Thermodynamics

The Second Law of Thermodynamics has always seemed depressing to me. It states that anything left to itself, without new energy to sustain its structure, will become continually more disordered. Molecules of different gasses in a container will move around until they all become thoroughly intermixed. Ice cubes in a glass of water will melt. And as the sayings go, “You can’t unscramble an egg” and “Whatever can go wrong will go wrong.”

This tendency towards disorder, this inability of things to remain what they are unless  energy sustains them, is entropy. The Second Law asserts that entropy in the universe always increases. Sustainability is always in doubt. And in human affairs, entropy implies that nothing worthwhile—relationships, art, satisfying work, better communities—can remain finished and stable on its own. Ugh.

But Steven Pinker takes a more generous view in a short piece written for Edge and reprinted in the Wall Street Journal in 2016.

The Second Law also implies that misfortune may be no one’s fault. The human mind naturally thinks that when bad things happen—accidents, disease, famine—someone must have wanted them to happen….[But] not only does the universe not care about our desires, but in the natural course of events it will appear to thwart them, because there are so many more ways for things to go wrong than to go right. Houses burn down, ships sink, battles are lost for the want of a horseshoe nail.

entropy (keelynet.wordpress.com)

keelynet.wordpress.com

And, Pinker adds, without a flow of economic energy, people go hungry. “Matter doesn’t spontaneously arrange itself into shelter or clothing, and living things don’t jump onto our plates to become our food. What needs to be explained is not poverty but wealth.”

I found myself thinking about entropy in connection with conspiracy theories. For some, it may feel satisfying to account fully for a disaster by tracing the stealthy plots and actions of human enemies. But entropy and its agents— coincidence, irrational human impulse, materials and systems gone awry, among others—are all on stage as well, more difficult to identify, and much less satisfying to blame.

Pinker’s perspective also cast a new light for me on the familiar serenity prayer: that we should try to accept what we cannot change, find the courage to change what we can, and hope that we can tell the difference between the two. The Second Law puts a foundation under that difficult first step, the acceptance of things that we cannot change. It’s easier to do that when we understand that conditions don’t easily stay as they are in the first place–and often no one is at fault. We do out best to stay healthy, for example, so we’re reluctant to accept that our body will fail eventually for reasons beyond our control. Committees and governments may bring the benefits of social order for a period of time, but we can recognize how such social efforts will fall into stagnation or conflict eventually without anyone being a villain.

Entropy is sometimes described as a re-organizing and re-forming force, rather than as a dis-ordering one. An organized thing will if left to itself take on new forms, occupy more or less space, detach and reattach. If it’s the original thing that you are focused on, then indeed that thing will have “broken down.” Ice cubes melt and disappear. But a friendship may rearrange itself into a marriage, then into a divorce, then into a business partnership. Stars explode, their atoms of metals fly out into the cosmos and come together again in the Earth and in us. Entropy, transformation, Buddhist impermanence.

Still, for Pinker, it’s the disruptive aspect of the Second Law that we underestimate. In fact it “defines the ultimate purpose of life, mind and striving: to deploy energy and information to fight back the tide of entropy and carve out refuges of beneficial order.” Appreciating the Second Law means pursuing such purposes more consciously while understanding that, without blame, the tide always comes back in.