The Greatest Show on Earth: The Evidence for Evolution

Richard Dawkins’ latest book The Greatest Show on Earth: the Evidence for Evolution is a great read. If you don’t believe in evolution (Dawkins would call you a ‘history-denier’) the book won’t be of interest to you. If you believe in evolution and want to go deeper into the subject, want to know more about examples of evolution in everyday life and a load of other interesting facts (does a whale have hind legs?), then this book is for you.

The thirteen chapters are an easy and engaging read. The only place the reading gets hairy is in Chapter 5 where the evolution of E. coli in test tubes for 20 years is discussed (which is nonetheless fascinating). The standout ideas for me were the following:

- Chapter 8, You Did it Yourself in Nine Months, is about embryology with the main take away that DNA is not a ‘blueprint’ for building the body. Blueprints are reversible and are 1-to-1 where DNA-to-final-body is not. A better analogy is a recipe.

- In the same chapter, the roundworm Caenorhabditis elegans is discussed. In this discussion Dawkins gives a simple overview of how from the original egg you get a newly hatched larva of 558 cells. The key to it (and similarly in the human egg cell) is asymmetric cell division. The original cell has a front and rear end so that when it divides they go on to form (like a recipe) the front and rear of the worm.

- Chapter 13, There is Grandeur in this View of Life, has a section talking about what Dawkins calls the four ‘memories’ or ways in which information from the past is recorded for future use. The memories include the gene pool, the immune system, the nervous system, and culture. The four memories are all made possible by the Darwinian process of non-random DNA survival.

In the last chapter, Dawkins gives this definition of natural selection: “… the case of DNA, we understand pretty well how the information content builds up over geological time. Darwin called it natural selection, and we can put it more precisely: the non-random survival of information that encodes embryological recipes for that survival.”