"Which of the following statements comes closest to your views on the origin and development of human beings?", asks the question on Gallup's national poll. In each of the 9 times this poll has been conducted in America since 1981, the clear winner has been the response "God created human beings pretty much in their present form at one time within the last 10,000 years or so." The percentage of vote in 2008 - 44%.
Richard Dawkins is not a patient man. He is many things - reputed evolutionary biologist, author of some of the great popular science books of our time, an outspoken atheist, a lightening rod in debates about religion and science, a fellow of the British Royal Society as well as the Royal Society of Literature (I wonder how many people have that dual distinction). A man of many qualities. But he is not a patient man. His frustration with irrationality is all too apparant, never too far from the surface of The Greatest Show on Earth.
Dawkins has written nine books before this one, most of them on the broad theme of evolutionary biology. In The Greatest Show on Earth, he lays out for probably the first time in all his books, the real evidence behind evolution. For the first time, he sets out to convince readers that we were not all created in a week of really busy work, but evolved from a single organism over billions of years through a process of non-random natural selection.
Evolution is a fact. Beyond reasonable doubt, beyond serious doubt, beyond sane, informed, intelligent doubt, beyond doubt evolution is a fact. The evidence for evolution is at least as strong as the evidence for the Holocaust, even allowing for eye witnesses to the Holocaust. It is the plain truth that we are cousins of chimpanzees, somewhat more distant cousins of monkeys, more distant cousins still of aardvarrks and manatees, yet more distant cousins of bananas and turnips ... continue the list as long as desired. That didn't have to be true. It is not self-evidently, tautologically, obviously true, and there was a time when most people, even educated people, thought it wasn't. It didn't have to be true, but it is. We know this because a rising flood of evidence supports it. Evolution is a fact, and this book will demonstrate it. No reputable scientist disputes it, and no unbiased reader will close the book doubting it.
You get the point. Dawkins being who he is, the evidence he puts together is nothing short of spectacular. Below, I try to summarize the case he presents.
Note: This summary is more for deepening my own understanding of the story I just read. If this were a book of fiction, I would probably put a spoiler alert right about here. But of course, the very point of the book is that evolution is no fiction!
The case for evolution, as made by The Greatest Show on Earth
1. It is possible to create a wide diversity of plants and animals from common ancestor. Human breeders did it deliberately with the creation of 200+ breeds of wildly different breeds of dog, all 'hand sculpted' from the same parent, the wolf Canis lupus, over a span of just a few centuries.
2. Without deliberation, agents in nature often play the role of 'breeders' by creating an environment where one kind of characteristic in a species is preferred for reproduction and survival than another. A great example are insects that are attracted to a particular color more than others and hence preferentially pollinate certain flowers.
3. Many species have dramatically changed some of their more dominant features 'before our very eyes' in the last few decades because of clearly identifiable environmental changes that preferred the new features. Scientists have been doing it too in controlled experiments. The most dramatic form of this - the Lenski experiment. Lenski and his team at Michigan State have created, in a supremely controlled environment, 45,000 generations of E coli bacteria in separate flasks over the past two decades and more! The results are a thumping endorsement of every prediction that evolutionary bilogy would make. The Lenski experiment, which Dawkins explains in gory detail, is, I am pretty certain, the most beautiful scientific experiment I have ever heard of. Worth the price of the book just to read this chapter!
4. The fossil records are full of species that show partial transitions from one kind of animal to another. So many of these 'missing links' have now been found in fossilized form that there isn't much 'missing' in our understanding of the path evolution took.
5. No fossil has ever been found 'in the wrong geological stratum'. Not once has a single fossil been found of an animal that was supposed to have evolved after the time of that layer of earth.
6. The creation of a really compled organism from one cell happens every day, and all around us. It is called pregnancy!
7. The distribution of animals on different islands and continents is exactly as we would expect if they are all cousins evolved from shared ancestors.
8. Animals that are close cousins on the evolutionary tree have fundamental similarities in things like their skeletal structure that make it impossible to deny that they arise from similar recent parentage.
9. Animals all around us (including ourselves) have organs that serve no ostensible purpose. They remain vestigial reminders of a history long in the past when those organs were indeed useful, in a different evolutionary stage. Our evolutionary history, in other words, 'is written all over us'.
Each of the points above corresponds roughly to a chapter in The Greatest Show on Earth. And each is supported by some amazing pictures - I am sure a future release of the book will come out with a black and white version of the pictures to make the book cheaper. Take my word for it - buy the book with the color pictures.
There are two Richard Dawkins-es in The Greatest Show on Earth. One is the curmudgeonly, monomaniac who is forever belittling the creationists and the 'evolution-is-just-a-theory' brigade. While I get the point and can largely understand the frustration being expressed, this Dawkins started to get on my nerves after a while. But then there is the other Dawkins. The scientist whose pleasure in his subject is uplifting and infectious. The teacher who takes us on many, many digressions during the course of the story, each an exquisite ride. It is this Dawkins, the brainy, excited, goggle eyed one that I am a fan of. He is the guy who makes this book such a pleasure to read.
'There is grandeur in this view of life' says Dawkins, quoting Darwin. I could say the same about his book.