The Biology of War

In 2013 scientific attention was focused on a pair of books that addressed why humans have war. Edward O. Wilson, in his book The Social Conquest of Earth, maintained that war was a human instinct, and that humans have had war as long as we have existed as a separate species. (This was not the main thing Wilson’s book was about.) In contrast, science writer John Horgan, in his book The End of War, argued that war is something that humans learned to do and that we can unlearn.

While this seems like an important debate, I fear that it is mostly over semantics. Humans have had violent conflict as long as we have existed (a fact Horgan does not deny), but full-scale wars have occurred only in the last 11,000 years or so. Did I miss something? When human population started to increase, and humans started living in defined locations such as cities, then violent conflicts became big enough to be classified as wars. Isn’t war just a big violent conflict? Was the conflict between the Cherokees and the Creeks, culminating in the Battle of Taliwa in 1755, a war or an intertribal conflict? I don’t think this would have made any difference to Nanyehi, my 6^th great grandmother, whose saw her husband killed in that battle, and who became a Cherokee war hero right at that moment. She was a war hero, even though no massive troop engagements were involved. She, also at that moment, became an advocate for peace, because whether it was a war or a mere conflict, she was a widow and her two children were orphans.

Nevertheless, Horgan does get us to think about a few very interesting things. He makes the invalid argument that, if violence is part of human nature, then why has war been so sporadic? I think it is obvious why he is wrong. We all feel the occasional zeal of violence; the fact that we do not always put it into action does not mean that it is not part of our nature. But the interesting point is this: war does not always occur when resources are scarce or when there is hostility. War is an emergent property, I think, that must be induced under the right circumstances. Not every conflict of interests between tribes or nations turns into war, just as not every dry grassy field burns. But when war is induced, the violent component of human nature is waiting there as fuel.

Still, Horgan brings up a good point, when we consider that war is not something that automatically happens but something that we must decide to do. To a certain extent, it is something that we have to learn. Sometimes it becomes a tradition into which we are trapped. That is, war is something that our leaders lead us into. Most people (except psychopaths) have a natural tendency to want to not harm other people. But this resistance to major acts of violence can be overcome by intense training, commands from authority figures, long-range weapons, and propaganda. The long-range weapons allow us to kill others without having to see them die.

Horgan makes the point that we start wars not because we are wolves but because we are sheep. We may be inclined to seek peaceful solutions, but we do whatever our leaders tell us to. This is the aspect that can make a whole population become violent, not just the one to two percent who are psychopathic.

The violence that leads easily to war is part of human nature. But peace is also part of human nature. Because of this, war may not be inevitable, if we can break the cause-and-effect chain that keeps war going. This chain goes all the way back to the story of Cain and Abel, which fundamentalists accept as history and I accept as an image. You can think of each human as half Cain, half Abel. Which half will we choose? Perhaps we will always have war, but there is room for diminishing its intensity and frequency.

And to do so we need to cultivate empathy. We need to practice it, think about it, incorporate it into our movies and novels and music and art. We cannot eradicate our violent nature, but maybe we can encyst it so that it does not poison the rest of our collective person. We have to tell ourselves, in celebration, that we all feel the same things. We all love our children and most of our neighbors and most of the people we work with. (As for the ones we don’t love, maybe we can tolerate them.) As Nanyehi said, “The white men are our brothers. The same house shelters them, and the same sky covers us all.”

In Memory of Lynn Margulis

This essay will also be posted on my website at www.stanleyrice.com.

One of the greatest evolutionary scientists, Lynn Margulis, died last November 22. In this essay I would like to reflect on her contributions to our understanding of the world. Not just of a narrow aspect of science, but the whole world.

Lynn was a child prodigy who began her university studies at age 14. In graduate school, she studied genetics, and married her fellow graduate student, Carl Sagan (who was as creative and large a thinker as she). She was not content to just learn what others said about genetics. She wanted to understand why some traits were inherited only through the mother’s side. These traits appeared to be passed on not through the chromosomes in the nucleus but through the mitochondria, which are tiny energy factories inside of most cells. Some plant traits appeared to be passed on through chloroplasts, the tiny green photosynthesis factories in many plant cells. This meant that mitochondria and chloroplasts had, and used, their own DNA. She wondered why they had that DNA. When she read about the work of some Russian scientists in the early twentieth century, she had her answer. Mitochondria and chloroplasts started off as bacteria, which moved into and took up residence inside of larger cells that already had nuclei. They did not consume the larger cell, nor did it consume them. Instead they formed a permanent partnership, which has been going on for billions of years. Mitochondria and chloroplasts began, she said, by symbiosis—cells living together. The result was the genesis of a new, complex kind of cell. She called this process symbiogenesis.

When Lynn Sagan (later Margulis) wrote her paper, it was rejected fifteen times. She was persistent. Finally it was published. At first her ideas were scorned. But in less than a decade, most biologists were convinced that she was right. When I went to hear her speak, while I was a sophomore at the University of California, Santa Barbara (it was the first scientific seminar I ever attended), she was well received, even though the professor who introduced her made some off-color jokes. At the time, I was a creationist, and I thought that there were only two alternatives to the origin of a complex cell: either gradual evolution, or sudden creation. Lynn Margulis presented a third alternative. Her view was entirely evolutionary, of course; but the host cell and the bacteria had evolved, separately and gradually, then suddenly merged together.

Today Margulis’s view of the origin of mitochondria and chloroplasts is a textbook standard. Scientists are working on an even more amazing example of symbiogenesis: many believe that the nucleus itself is the evolutionary descendant of a bacterium that moved into a larger cell that did not yet have a nucleus. I suspect that this idea would have been too wild even for Lynn in the early days.

In her final years, Lynn was looking for evidence that cilia and “flagella” of complex cells (such as paramecia) were the evolutionary descendants of spirochete bacteria. She had some good circumstantial evidence, but never did find proof.

She was also the principal biological champion of the “Gaia” view of the Earth, a view first proposed by atmospheric scientists James Lovelock. All of the organisms of the Earth form a single network of life. The Earth is therefore not just the home of life, but is alive. Not every component of the Earth is alive, of course; but neither is every component of a cell. A cell has living components, such as mitochondria, and nonliving components, such as water. But nobody would say that a cell is not alive. By the same reasoning, the Earth is alive.

Lynn was pugnacious. She was not afraid of a good scientific debate. And she was not afraid to be wrong. Clearly she was wrong in her assertion that HIV is not an infectious virus. But if she had never taken the risk of being wrong, would she ever have had the insights that changed modern biology?

I had a chance to talk with Lynn Margulis in 2004, as I was preparing my Encyclopedia of Evolution. She was 66 years old at the time, and could have retired comfortably and with renown. But she was still fighting for recognition of yet more of her insights. I mispronounced her name, and she corrected me: the emphasis is on the first syllable, Margulis. She said I would only be allowed to make that mistake once. I didn’t make it again. She enjoyed what I had written in my encyclopedia but was not afraid to point out what she considered errors. When I dedicated Life of Earth to her last year, she left me a phone message saying that the dedication brought tears of happiness to her eyes. She bought copies and left them for students to read at the University of Massachusetts, where she worked. I am glad to have brought a little joy and appreciation into the life of this great scientist.

We can carry on Lynn’s legacy if we continue to think big about the world. When Lynn started, most scientists were trying to decompose the big picture down into component parts. But now, many scientists consider that the interactions of those components are the most important thing. An entire research institute, the Santa Fe Institute, is devoted to understanding complex interactions and emergent properties. Geneticists now know that humans and mice have about the same number of genes, and most of them are the same genes; the big difference between a mouse and a human is not the genes but the interactions among the genes. I like to think that Lynn contributed greatly to this important change in the scientific view of the world.

Announcement: I just posted a new YouTube video on www.youtube.com/StanEvolve. It will be up soon. Darwin comments on…Newt Gingrich?

Also, please send comments about what you would like to discuss, and thanks for the comments received.