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 gen- eration. Think about the food grown on farms. For about twelve thou- sand 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 some- thing 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.