Prof. John A. Dern
Mosaic: Humanities Seminar 852
January 30, 2015
Gradualism—the Principle Flows Through the River of Time
Although the Darwinian evolution theory came out 150 years ago when it was first introduced in On the Origin of Species in 1859, nowadays there are still many people who firmly believe in the creationism, even some who are well educated. In chapter three of River Out of Eden Richard Dawkins brings out this situation and refutes creationism by citing scientific experiments, and finally he points out that gradualism is a principle of the evolution nature world, one that becomes indispensable when one is trying to explain complex phenomena. At the beginning of chapter three, Dawkins quote a letter from an American minister who was an atheist but became a theist after he read an article in National Geographic. The minister believed that an orchid has to look and smell like a female wasp perfectly, otherwise it would not have been pollinated by a male wasp. Dawkins uses this letter as an example for two reasons. First, the title of American minister gives the audience a feeling of a well-educated person so it is not a minority of people who have the same problem as him (Dawkins 59). Second, this example shows “the Argument from Personal Incredulity,” by which many people use their own perspective as the standard by judge the whole of nature and many “obvious” events that not make sense in the natural world at all. Dawkins further explained his argument: “The general lesson we should learn is never to use human judgment in assessing such matters. Never say, and never take seriously anybody who says, ‘I cannot believe that so-and-so could have evolved by gradual selection’” (Dawkins 70). Dawkins refutes personal incredulity based on people’s cognitive process. Although he does not order the objects by intelligence, the examples show a strong recursive relationship among them. Humans are the cleverest among birds, fish and swaps, while birds have bigger brains than fish and fish have bigger brains and better eyesight than swaps. Initially, Dawkins makes a very simple and real-life example: “the stuntman’s resemblance to the star is usually extremely superficial, but in the fleeting action shot it is enough to fool an audience” (Dawkins 62). Despite the fact that humans have the most developed brains among all the tellurians and the best eyesight among vertebrates, we cannot say that we are hard to be fooled. In fact, we are much easier to be fooled than we imagine. This example should be considered as a foreshadowing before Dawkins officially refutes the minister’s statement by using scientific experiments which makes the audiences or the opponents realize that we should put ourselves in the object’s position instead of using our own judgment arbitrarily. Dawkins further explains his reason by an example of insects: “It is known that insect eyes see the world in a completely different way from our eyes. The great Austrian zoologist Karl von Frisch discovered as a young man that they are blind to red light but they can see—and see as its own distinct hue—ultraviolet light, to which we are blind” (Dawkins 66). Dawkins, to make his point, introduces two experiments on black-headed gulls and stickleback, done by Robert Mash and Niko Tinbergen, respectively. Mash pointed out that black-headed gulls would consider a black wooden model as a real gulls, yet it is only a wooden rod without any body, legs, wings or tail. Dawkins’s teacher, Tinbergen found out that stickleback fish mistakenly thought a red mail van and a silvery dummy were their same species! By citing these two experiments, Dawkins gives adequate evidence to prove that limited intelligence and eyesight suggest that organisms do not have to be “perfect” to work and that they can be easily fooled. Instead, most of the animals judge whether an object is their same kind by only one or few characteristics. After offering these experiments, Dawkins summarized that:“The reason eyes and wasp-pollinated orchids impress us so is that they are improbable by luck are odds too great to be borne in the real world. Gradual evolution by small steps, each step being lucky but not too lucky, is the solution to the riddle” (Dawkins 83-84). This summery reflects the relationship between the experiments and gradualism where profound change is the cumulative product of slow but continuous processes. Dawkins used the river metaphor to reflect the species’ separation: “The two rivers are separate and destined to become more and more separate” (Dawkins 7), the long goodbye occurs when the river splits, the point at which the river splits represents speciation. And the meaning of gradualism exactly complements his statement which the evolution of new species by gradual accumulation of small genetic changes over long periods of time (Dawkins 83-84). Moreover, the discussion of gradualism relates to the discussion about speciation in chapter one. For instance, when Dawkins talks about the speciation of gray and red squirrels he mentions,: "Their genetic rivers have drifted too far apart, which is to say that their genes are no longer well suited to cooperate with one another in bodies" (Dawkins 7). In chapter 1 Dawkins only gives the conclusion that only after a whole process starting when the ancestors of gray and red squirrels were separated by the Atlantic, now they can no longer interbreed with each but he does not explain what exactly the process is. After we finish the chapter three, which is based on the gradualism, we finally know the answer of this question of why the genes of gray squirrels and red squirrels were evolved too different to act as good companions after thousands of years’ of reproduction. Gradualness has played a critical and irreplaceable role in species’ evolution since billions of years ago and almost no living things escape this principle. The evolution of species happens silently throughout time since a human lifetime is too short to realize the changes, compared with evolutionary history. Even though human being are dominating the Earth, we are only like a fleeting shot in the “evolution movie” and gradualism is probably one of the most crucial ways to recognize ourselves and predict what we will be in the future.
Dawkins, Richard. Preface. River Out of Eden. New York; Basic Books, 1995.1-93. River Out of Eden. New York; Basic Books, 1995.