River Out of Eden

Title: River Out of Eden

Author: Richard Dawkins

Publisher: Phoenix 2004 (First published 1995)

ISBN: 9781857994056

Pages: 196

Reading Richard Dawkins is an inspirational venture. What makes the experience so rewarding is the clarity of thought and logical propositions that abound in the book. The explanations are so crystal clear that it would bathe the mental landscape in the pristine light of true knowledge. As the most convincing author in the genre of popular science, as well as being the most down-to-earth one, Dawkins has published many books, each of which is a gem in its own right. Many books are reviewed earlier in this blog itself and I am not a person who would waste an opportunity to get hold of one of Dawkins’ books. ‘River out of Eden’ is a great book that exposes the secret of the river of life that flows uninterrupted from the origins to the present moment. Conflicting and confusing responses may be elicited if one were to ask the reason for life existing on earth. Keeping aside philosophical and religious responses, what we learn from the book is that life’s only purpose is to perpetuate the genetic code that made it in the first place. All the infinite variations and subtle nuances exist for only one purpose – to replicate the DNA that is the basis of heredity – and to ensure its continuity in the world in the form of other beings spawned from the parent. This line of argument may seem blasphemous to some, outrageous to some other, but calm pondering of the basic issue of debate vindicates Dawkins’ stand. The book is adorned with an impressive list of books for future reading and sports a good index. Illustrations are done by Lalla Ward, the author’s wife, which blends harmoniously with the content.

The river flowing out of Eden is a stream of genes, forking billions of times along the way. When a species begins to separate in some way – geographic separation is the most common cause – a bifurcation is said to have taken place in the course of the river. Animals in the two separated streams can still produce offspring during the initial stages, but they don’t do it actually, because of the physical separation. Dawkins postulates that living bodies are only temporary vehicles in which the self-replicating genes find expression, in their flow through time. In fact, he likens the living organisms to the banks of the river, which helps the current to follow its course and not spilled over to other channels. Indian philosophers may bring to notice an arresting resemblance to the ancient spiritual speculation that the body is only a temporary seat of the soul, which itself is immortal. If the term, ‘soul’ is replaced with genes, Dawkins’ example emerges full blown out of the picture. But nothing like this can be further from the spirit of the book as well as Dawkins’ imaginative thought. Deceptive pitfalls await readers who connect science’s discoveries which are based on proof to idle speculation that masquerades as ancient philosophy. Explaining the concepts of mitochondrial DNA, the author establishes that all the people now alive on the planet descended from a single woman who lived around a quarter of a million years ago, most probably in Africa. This great great grandmother, also called Mitochondrial Eve for obvious reasons, was definitely not the only woman alive at that time. There might have been many males in that generation who have descendants today. But the DNA carried forward through the male line is resident in the nucleus of cells and gets eventually lost through sexual recombination. But mitochondrial DNA is passed only through the mother and is uncontaminated. Taking the frequency of random mutations into account, the period at which the ancestor lived could be estimated.

Every one of Dawkins’ books attempts to answer the probing questions posed by creationists to mock at evolution and its mechanisms. One of the commonplace tricks of the creationists is to describe the complexity of a biological artifact, like the eye, and then argue that such a complicated system will not function unless all its parts are complete. There will not be half an eye which would function, they would say. Now comes the statistical part – if an eye can’t function unless it is assembled in full, what are the chances that an entire eye is evolved wholesale by random mutation? Obviously, such a proposition would take a long time to accomplish. In fact, very long in the sense that the time required will be several orders of magnitude greater than the life of the universe! Dawkins, however, damns the argument in his exemplary style. He postulates that the eye need not be a whole organ to perform its function well. Hundreds of eye designs are seen in nature that varies in utility from rudimentary light detection to complex 3-D full-colour vision. All intermediate eyes are living contented lives in their animal bodies. In fact, evolution of the eye has taken place independently around forty times in the animal kingdom. This topic is a favourite one of the author, as we can see it mentioned in his other books as well, notably The Greatest Show on Earth. He adds dance of honeybees as a bonus in this book. This tells about the way in which a bee ‘describes’ about the location of food to its fellows in the hive in the form of a peculiar dance following the figure of ‘8’. What the author asserts is that even though the information interchange is very complicated and ingenuous, its development was not the result of any design, but only by the evolutionary pathways.

Dawkins appears to be well versed in programming and with concepts in modern communication engineering about how to transmit sound and picture over long distances without much loss. His narration of the differences between analog and digital signals is impressive. The supreme ease with which he makes comparison with the digital engineering systems and its biological counterparts helps readers to understand the concepts very well. The most commendable achievement might be the correct identification of DNA coding to be digital. Just as a digital system is a way of working with 1s and 0s, or two states of voltage levels, the DNA is coded with four digits, usually abbreviated as A, T, C and G. Dawkins assumes a fictitious scenario in which a message in ordinary English is interspersed in the genetic sequence of a life form without losing its effectiveness in carrying genetic information that is absolutely necessary for the life of the animal. A queer thought may be presented here as an armchair exercise. What if our entire genome are in fact messages in the language of a super-powerful alien race that somehow colonized the earth in its early phase and deposited the primordial DNA to see how it works? Most of the DNA is believed to be junk in the sense that no useful genes have been detected on these portions. But it is inconceivable that nature would go to the trouble of maintaining so large a part of the DNA for no apparent reason. Isn’t the thought intriguing that these junk regions contain some coded message from another race? It is the realm of science fiction, and if you replace it with divine language, believers could also be taken along. So, it is a double edged sword.

The book is highly recommended.

Rating: 4 Star