“This is a book about the positive evidence that evolution is a fact. It is not intended as an anti-religious book. I’ve done that, it’s another T-shirt, this is not the place to wear it again,” says Dr. Richard Dawkins in the introduction to his book The Greatest Show on Earth (17). This book is an organized presentation of copious numbers of the examples that support the evolutionary change over time via the process of natural selection. It raises many issues to a reader’s mind, and it helps provide a fuller understanding of the theory of evolution for the reader. In The Greatest Show on Earth, Dr. Dawkins clears away ambiguities.
Dr. Dawkins address evolutionary change via the process of natural selection – that is the process he is trying to help people to increase their understanding of in his book. It is important to know the difference between artificial selection, natural selection, and intelligent design. Dr. Dawkins gives an excellent explanation of artificial selection Chapter 2: Dogs, Cows, and Cabbages. Artificial selection is basically the process of breeding – it is what breeders do when they select animals that have the traits they want so that they can increase the expression of those traits thereby creating a breed. An example that Dr. Dawkins furnishes is that of the sculpting of the wild cabbage plant into domestic, delicious, and varied vegetables:
The wild cabbage, Brassica oleracea, is an undistinguished plant, vaguely like a weedy version of a domestic cabbage. In just a few centuries, wielding the fine and coarse chisels furnished by the toolbox of selective breeding techniques, horticulturalists have sculpted this rather nondescript plant into vegetables as strikingly different from each other and from the wild ancestor as broccoli, cauliflower, kohlrabi, kale, Brussels sprouts, spring greens, romanescu and, of course, the various kinds of vegetables that are still commonly called cabbage. (Dawkins 35)
As for natural selection, Dawkins explains, it is the same concepts as artificial selection. However, where breeders do the selecting in the process of artificial selection, nature does the selecting in natural selection. Also, in natural selection it is the gene pool that is randomly being sculpted, not just the appearance of the body of the cabbage that is consciously being changed. Natural selection contains the often-heard principle of “survival of the fittest.” For example, say there is a wild cat population, and a few cats have a gene that makes their claws grow longer, thereby making it easier for them to capture and kill prey, as well as climb and hide in trees. Now, these cats have a higher survival rate than the wild cats with claws that are a normal length. So, more of these cats with the mutant gene for longer claws survive and breed, thereby after many generations altering the appearance of the general wild cat population in the area. That is natural selection.
Intelligent design is completely different. It is not necessarily the belief that the Christian God created the universe and all the splendor in it, but it certainly is the belief that something created the universe, that everything did not just appear by chance. In essence, intelligent design says that when you look at a complicated watch or a breathtaking painting, you know there is a designer behind both things. Paint does not just slop over a canvas and turn into a Mona Lisa. Da Vinci had to paint it with his incredible talent. Intelligent design then says, if you ask who made a watch or a painting, it is reasonable to ask who made an intricate and unfathomable eye, or the fantastic supernovas instead of assuming they just fell together by chance.
After establishing his reasoned ground for natural selection, Dr. Richard Dawkins describes how scientists establish the ancient age of remains – one of the supports for the process of evolution via natural selection. He describes the procedures of evolutionary scientists as like that of “detectives who come late to the scene of a crime,” (83). By this he means that just as detectives go to pathologists with a murdered body and ask the pathologist to use their knowledge to determine the time of death by the rate at which a body cools after it dies and when rigor mortis sets in, an evolutionary scientist has time sensitive tools. Just as pathologists measure the temperature of the body and then compare the temperature to the rate at which a body cools, geologists, for example, measure the half-life of stable elements such as carbon – carbon dating – to determine how old a rock is. Once scientists can date their specimens, Dr. Dawkins explains, they can obtain a temporal sequence which helps them to establish the ancestry of species. He says:
Having established [the age of strata of rock]. . .we can then look at the fossils in successively younger strata, to see whether they constitute a sensible evolutionary sequence when compared with each other in sequence. Do they progress in a sensible direction? Do certain kinds of fossils, for example mammals, appear only after a given date, never before? The answer to all such questions is yes. Always yes. No exceptions. That is powerful evidence for evolution, for it was never a necessary fact, never something that had to follow from our method of identifying strata and our method of obtaining a temporal sequence. (Dawkins 96)
Creationists look at the fossil record and interpret it differently from evolutionists. The creationists say that no new species arise after the act of creation was done. Things were created in one week, and nothing new was created afterwards. Dr. Dawkins, however, says that speciation occurs continuously. He gives in The Greatest Show on Earth the example of the divergent fauna in African lakes:
There’s good evidence. . .that the level of Lake Malawi. . .rises and falls dramatically over the centuries, and reached a low point in the eighteenth century, more than 100 meters lower than the present level. Many of its islands were not islands at all during that time, but hills on the land around the then smaller lake. When the lake level rose, in the nineteenth and twentieth centuries, the hills became islands, ranges of hills became archipelagoes, and the process of speciation took off among the cichlids that live in shallow water, known locally as Mbuna. Almost every rocky outcrop and island has a unique Mbuna fauna, with endless colour forms and species. As many of these islands and outcrops were dry land within the last 200-300 years, the establishment of the faunas has taken place within that time. (236-237)
At another point in his book, Dr. Richard Dawkins presents another support for evolution by natural selection when he shows that evolution tweaks original organisms to create new ones rather than “going back to the drawing board” to create completely new organisms from scratch. He puts it this way: “we shall continually find examples of evolution correcting an initial ‘mistake’ or historical relic by post hoc compensation or tweaking, rather than by going back to the drawing board as a real designer would” (299). An example that Dr. Dawkins presents of such tweaking is the blowhole of a dolphin. He writes:
The dolphin’s blowhole goes to great lengths to correct a problem that would never have arisen at all if only it breathed with gills, like a fish. And many of the details of the blowhole can be seen as corrections to secondary problems that arose when the air intake migrated from the nostrils to the top of the head. A real designer would have planned it on the top of the head in the first place – that’s if he hadn’t decided to abolish lungs and go for gills anyway. (299)
The Greatest Show on Earth Dr. Dawkins’ organized presentation of copious numbers of the examples that support the evolutionary change over time via the process of natural selection. He helps to provide a fuller understanding of the theory of evolution for anyone who reads his book. Certainly, he helped to deepen my understanding of the subject matter. Dr. Dawkins states he is trying to reach the “history-deniers,” as he calls people who do not believe evolution is scientific fact, and change their minds. He also says he has a second audience, the audience of people who are not “history-deniers” but who are not equipped with a full understanding of the evolutionary process via natural selection. In order to accomplish this purpose he presents the foremost examples of evolutionary change in an easy to understand way. Through the baby steps that he takes with his readers, Dr. Dawkins succeeded in his mission to equip at least one more person with a deeper understanding of the process of evolution through natural selection. For now that I have read The Greatest Show on Earth I have a better grasp of the dating of fossil records and what fossil records tell scientists, how evolution works by correcting flaws and making tiny changes over a period of time, and the ongoing process of speciation to name just a few points.
Works Cited
Dawkins, Dr. Richard. The Greatest Show on Earth: The Evidence for Evolution. New York: Free Press, 2009. eBook.
