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ME AND YOU AND EVOLUTION, TOO
I think it started with the bees. I was about seven years old, and I watched them … all day. That Sunday, I had read the "Ripley's Believe It or Not" column in The Washington Post, which claimed, "The Bumblebee: Considering its size, shape, and wingspan, is an aerodynamic misfit—which should be unable to fly!" It was frustrating, because here they were flying. I got caught up in the details. Their wings looked like decoration, no more useful than a store-bought bow glued to a gift. I looked closely at my mother's azalea flowers—so many delicate parts. Somehow, the bees were able to get in there, fill their pollen baskets from the flowers, and fly away again and again.
How did bees learn to do all that? Where did they come from? Where did the flowers come from? Come to think of it, how did any of us get here? Why did Ripley's have it so obviously wrong? I was getting pulled into something much larger than myself. The yearning to know about nature and where or how we fit in is deep within all of us. As I learned about evolution and descent by natural selection, the answers fell into place.
We are all aware that evolution happens, because we all have parents. Many of us have, or will have, children. We see the effects of heredity up close and personal. We've also experienced firsthand what Charles Darwin called descent with modification: the way that an entire population of living things can change from generation to generation. Think about the food grown on farms. For about twelve thousand years, exploiting the phenomenon of evolution, humans have been able to modify plants through a process known as artificial selection. In wheat farming and horse racing we call it breeding. Darwin realized that breeding (and domesticating) plants and animals involves exactly the same process that occurs naturally in evolution, only accelerated with the help of humans. This natural process produced you and me.
Once you become aware—once you see how evolution works—so many familiar aspects of the world take on new significance. The affectionate nuzzling of a dog, the annoying bite of a mosquito, the annual flu shot: All are direct consequences of evolution. As you read this book, I hope you will also come away with a deeper appreciation for the universe and our place within it. We are the results of billions of years of cosmic events that led to the cozy, habitable planet we live on.
We experience evolution every day in our culture as well. People everywhere are fascinated with other people. That's why we have sidewalk cafés, televisions, and gossip magazines. We interact to produce more of us for future generations. People are fascinated with their bodies. Turn on the television to any channel. If it's youth-oriented music programming, you'll see advertisements for skin medicines to make you look healthy, for deodorants to modify your natural scents, and for hair and makeup products to render you more attractive to a potential mate. If it's a staid news channel, you'll see ads for improving your breathing, your bones, and, of course, your sexual performance. None of these products would be produced were we not walking, talking products of evolution.
We are all so much alike, because we are all human. But it goes deeper than that. Every species you'll encounter on Earth is, near as we can tell, chemically the same inside. We are all descended from a common ancestor. We are shaped by the same forces and factors that influence every other living thing, and yet we emerged as something unique. Among the estimated 16 million species on Earth, we alone have the ability to comprehend the process that brought us here. Any way you reckon it, evolution is inspiring.
Despite all of that, a great number of people in many parts of the world—even in well-educated parts of the developed world—are resistant or hostile to the idea of evolution. Even in places like Pennsylvania and Kentucky, here in the United States, the whole idea of evolution is overwhelming, confusing, frightening, and even threatening to many individuals. I can understand why. It's an enormous process, unfolding over times that dwarf a human lifespan—across billions of years and in every part of the world. And it's profoundly humbling. As I learned more about evolution, I realized that from nature's point of view, you and I ain't such a big deal. Humans are just another species on this planet trying to make a go of it, trying to pass our genes into the future, just like chrysanthemums, muskrats, sea jellies, poison ivy … and bumblebees.
Many people who are troubled by evolution want to suppress teaching the whole concept of descent through natural selection in schools. Others try to push it aside or dilute it by casting doubt on the established science that supports it. State education standards allow the teaching of fictitious alternatives to evolution in Texas, Louisiana, and Tennessee. Even though the people who support these curricula live lives that are enriched in many ways by science and engineering (everything from running water and abundant food to television and the Internet) they avoid the exploration of evolution, because it reminds us all that humankind may not be that special in nature's scheme. What happens to other species also happens to us.
I continually remind people what is at stake here. Our understanding of evolution came to us by exactly the same method of scientific discovery that led to printing presses, polio vaccines, and smartphones. Just as mass and motion are fundamental ideas in physics, and the movement of tectonic plates is a fundamental idea in geology, evolution is the fundamental idea in all of life science. Evolution has essential practical applications in agriculture, environmental protection, medicine, and public health. What would the deniers have us do? Ignore all the scientific discoveries that make our technologically driven world possible, things like the ability to rotate crops, pump water, generate electricity, and broadcast baseball?
Even the theological objections to evolution stand on shaky ground. For the last century and a half, ever since the publication of Darwin's On the Origin of Species in 1859, many people have come to believe that evolution is in conflict with their religious beliefs. At the same time, many people around the world who hold deep religious convictions see no conflict between their spiritual beliefs and their scientific understanding of evolution. So the naysayers are not only casting doubt on science and nonbelievers; they are also ignoring the billions of non-conflicted believers around the world, dismissing their views as unworthy.
I'll admit that the discovery of evolution is humbling, but it is also empowering. It transforms our relationship to the life around us. Instead of being outsiders watching the natural world go by, we are insiders. We are part of the process; we are the exquisite result of billions of years of natural research and development.
Frankly, my concern is not so much for the deniers of evolution as it is for their kids. We cannot address the problems facing humankind today without science—both the body of scientific knowledge and, more important, the process. Science is the way in which we know nature and our place within it.
Like any useful scientific theory, evolution enables us to make predictions about what we observe in nature. Since it was developed in the nineteenth century, the theory itself has also evolved, by which I mean that it's been refined and expanded. Some of the most wonderful aspects and consequences of evolution have been discovered only recently. This is in stark contrast to creationism, which offers a static view of the world, one that cannot be challenged or tested with reason. And because it cannot make predictions, it cannot lead to new discoveries, new medicines, or new ways to feed all of us.
Evolutionary theory takes us into the future. As the foundation of biology, evolution informs big questions about emerging agricultural and medical technologies. Should we genetically modify more of our foods? Should we pursue cloning and genetic engineering to improve human health? There is no way to make sense of these issues outside of an evolutionary context. As an engineer trained in the U.S., I look at the assault on evolution—which is actually an assault on science overall—as much more than an intellectual issue; for me, it's personal. I feel strongly that we need the young people of today to become the scientists and the engineers of tomorrow so that my native United States continues to be a world leader in discovery and innovation. If we suppress science in this country, we are headed for trouble.
Evolutionary theory also takes us into the past, offering a compelling case study of the collaborative and cumulative way that great scientific discoveries are made. In some sense the concept of evolution can be traced to the Greek philosopher Anaximander. In the sixth century BC, after evaluating fossils, he speculated that life had begun with fishlike animals living in the ocean. He had no theory of how one species gave rise to another, however, nor did he have an explanation of how Earth acquired its stunning biodiversity. Nobody would, for another two millennia. Ultimately, the mechanism of evolution was discovered by two men at very nearly the same time: Charles Darwin and Alfred Wallace.
You've probably heard a great deal about Darwin. You may not have heard so much about Wallace. He was a naturalist who spent a great deal of time in the field studying and collecting specimens of flora and fauna. He traveled in the Amazon River basin and in what is now Malaysia. Through his far-flung geographic and intellectual explorations, Wallace formulated his theory of evolution independent of Darwin, and described an important aspect of the evolutionary process, often still referred to as the "Wallace effect" (more about that in chapter 12). Wallace recognized humans as just one part of a much broader living world. Quoting from his 1869 book The Malay Archipelago, "… trees and fruits, no less than the varied productions of the animal kingdom, do not appear to be organized with the exclusive reference to the use and convenience of man…" In Victorian England, such a point of view was controversial to say the least.
Darwin had the earlier start. Wallace was just eight years old in 1831 when the twenty-two-year-old Darwin had a remarkable opportunity as an energetic young man to go to sea aboard the HMS Beagle. He realized that if humans could turn wolves into dogs, then new species could come into existence by the same means naturally. He also saw that populations do not grow and grow indefinitely, because their environment will always have limits on the resources available. Darwin connected these ideas by observing that living things produce more offspring than can survive. The individuals compete for resources in their respective ecosystems, and the individuals that are born or sprout with favorable variations have a better shot at survival than their siblings. He realized that, left unchecked, the process of natural selection would result in the great diversity of living things that he would go on to observe.
Recognizing the two scientists' convergent views, colleagues arranged for Wallace and Darwin to present a paper together at a meeting of the Linnaean Society in London in 1858. The paper was based on a letter that Wallace had written to Darwin, along with an abstract for a paper that Darwin had written in 1842. The revolutionary impact of the joint presentation was not immediately obvious to all of those in attendance. Thomas Bell, the president of the Linnaean Society, infamously reported that no important scientific breakthroughs had occurred that year: "The year which has passed has not, indeed, been marked by any of those striking discoveries which at once revolutionize, so to speak, the department of science on which they bear…"
The publication of On the Origin of Species in 1859 created a sensation and proved President Bell spectacularly wrong. It also made Darwin far more famous than Wallace, as Darwin remains to this day. His ability to articulate the theory of evolution is still astonishing. On the Origin of Species remains a remarkable and remarkably readable book, readily available in hardback, paperback, and online a century and a half later. In it, Darwin gives us example after example of evolution and explains the means by which it happens, providing both the facts and the mechanism in one volume.
Evolution is one of the most powerful and important ideas ever developed in the history of science. It describes all of life on Earth. It describes any system in which things compete with each other for resources, whether those things are microbes in your body, trees in a rain forest, or even software programs in a computer. It is also the most reasonable creation story that humans have ever found. When religions disagree about just creation, there is nothing to do but argue. When two scientists disagree about evolution, they confer with colleagues, develop theories, collect evidence, and arrive at a more complete understanding. Every question leads to new answers, new discoveries, and new smarter questions. The science of evolution is as expansive as nature itself.
Evolution goes a long way toward answering the universal question that ran through my brain as a kid, and still does: "Where did we come from?" It also leads right into the companion question we all ask: "Are we alone in the universe?" Today, astronomers are finding planets rotating around distant stars, planets that might have the right conditions for supporting life. Our robots are prospecting on Mars looking for signs of water and life. We're planning a mission to study the ocean of Jupiter's moon Europa, where there is twice as much seawater as there is here on Earth. When we go seeking life elsewhere, the whole idea of what to look for, and where to look for it, will be guided by our understanding of evolution. Such a discovery would be profound. Proving that there is life on another world would surely change this one.
The great questions of evolution bring out the best in us: our boundless curiosity, and our boundless ability to explore. After all, evolution made us who we are.
Copyright © 2014 by William S. Nye