In The Ancestor’s Tale Richard Dawkins narrates human evolution backwards, from the current point in time into the past, stopping at each point where the line of evolution converges with another line in a common ancestor, which Dawkins calls a concestor. Dawkins pretends that he is organizing the book in the same way as Chaucer organized his Canterbury Tales, but in fact this is just a pretense. With a few minor exceptions, Dawkins tells the concestral stories in his own voice. He moves backwards, systematically, through 36 or so points of convergence, until finally he reaches the starting point, the origin of life, which for Dawkins means the moment, some one billion or two billion or three billion years in the past, when a complicated set of chemical molecules developed the capacity to replicate themselves, and to pass their basic characteristics on to their replicated offspring.
This organizational pattern at first seemed perverse, but finally it worked. Dawkins uses the opportunity posed by each concestor to discuss the species, phyla, and specific evolutionary issues the concestor raises. By the end of the book, he has covered most of the major and many of the minor forms of life on the earth. Not surprisingly, mammals get a lot of emphasis.
Dawkins is the author of the The Selfish Gene, an influential and well known book that I found harder going than this one, though the length of The Ancestor’s Tale, 614 pages of text, not counting notes and bibliography, was a challenge. He is one of the leading geneticists in the world, and well known as an arch evolutionist, an opponent of all who would substitute supernatural explanations for science. He does not hesitate to admit points where science as yet remains uncertain. A primary example is the presence of “wheels” that spin on a central hub inside a large number of microorganisms. Advocates of intelligent design point to this element as proof of a Creator—they believe it represents too complicated a feature for evolution to produce alone. Dawkins, though he does not know how to explain the presence of these wheels, is confident there is a scientific explanation. He bases this confidence on the fact that for so many other aspects of life there are logical, scientific explanations. He doesn’t discount the existence of a supreme being, but he doesn’t accept any such being’s role as necessary in the process of evolution.
Dawkins can be cranky. He stops now and then to complain about George Bush or war policy. He takes potshots as the opportunities come along at creationists and others who reject evolution. This adds flavor and vigor to the book. But these are minor undercurrents. His main focus is on evolutionary processes and the development of life.
My favorite chapters were the early ones in which he discussed recent evolutionary developments leading up to modern humans. His discussion of our shared common ancestry with chimpanzees, and the divergence of our two evolutionary paths some seven million years in the past, is fascinating. The further back in time he moves, the more challenging the book becomes. It is easier to identify with a gibbon than it is with a shrew or a sponge. He often stops along the way to talk about various scientific concepts, such as continental drift and its effect on human evolution, or about dating techniques used by biologists in speculating when certain events occurred, and so on. He is always willing to consider various scientific explanations for why certain things happened. He is never willing to accept supernatural explanations. He has a passionate faith in the power of science to explain, a passionate faith in the all-encompassing power of evolution.
I especially enjoyed the chapter on the development of eukaryotic cells, that is, cells that incorporated bacteria in their structure to accomplish various purposes. Their development made the development of more complex life forms, such as our own, possible. I also enjoyed the discussion of the development of multi-cellular organisms. I was particular interested in Dawkins’ insistence that evolution is not necessarily a process of improvement. Rather, it is a process of development, from point A to point B. Creatures that exist today—bacteria, sponges, elephants, people—do not represent organisms that are necessarily more “advanced” than organisms from the past—they are merely evolved. They represent another step in the evolutionary process. Late in the book, Dawkins does talk about the notion of progress, and how it can, in a sense, happen as a result of evolution.
A major development in evolutionary biology since I began to study it in high school in the 1960s is the use of molecular analysis. Rather than relying on morphological similarities in fossilized bones, scientists can analyze with relative certainty the DNA and other organics properties of organisms and determine how closely they are related to each other. This process of analysis is in fact what makes this book possible: it enables Dawkins’ effort to trace human evolution, and the development of life itself, back some billion years and further.
What the backwards narrative structure of The Ancestor’s Tale allows Dawkins to do is discuss the development of life, the process of evolution, and the great biological diversity that has developed on this planet over the past four billion years.
For those of us schooled in the humanities, conditioned to anthropomorphize, to view the human being as the center of all things, Dawkins' method can be unsettling. Humans from his point of view are simply organisms; their distinguishing characteristics are their large brains, their use of language (unique among animals) and their capacity for self-reflection and abstract thought. Life for Dawkins is a series of chemical reactions and biological processes. He is confident they can be explained in a cold, rational, logical way, using the scientific process. One may at first resist this way of looking at life and our existence on earth, but Dawkins is confident, logical, and informed, and he gradually wins you over.
In the final chapter, Dawkins grows reverential. There is a clear sense of piety, but it is piety for the diversity and complexity of life on earth, and of the human mind’s ability to study, appreciate, and ultimately to understand it. Concluding, he writes:
“Pilgrimage” implies piety and reverence. I have not had occasion here to mention my impatience with traditional piety, and my disdain for reverence where the object is anything supernatural. But I make no secret of them. It is not because I wish to limit or circumscribe reverence; not because I want to reduce or downgrade the true reverence with which we are moved to celebrate the universe, once we understand it properly. “On the contrary” would be an understatement. My objection to supernatural beliefs is precisely that they miserably fail to do justice to the sublime grandeur of the real world. They represent a narrowing down from reality, an impoverishment of what the real world has to offer. [614]
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