The Greatest Show on Earth: The Evidence for Evolution by Richard Dawkins
While Richard Dawkins has been publishing works popularizing aspects of the theory of evolution by natural selection since The Selfish Gene in 1976 (which I reviewed), he had never set out in one volume the case for the evidence for evolution, assuming it as given in his previous works and exploring other aspects or the implications of the theory. To rectify this gap in his oeuvre, he sets out the multiple lines of evidence in 2009’s The Greatest Show on Earth (the only game in town), and begins by explaining what we mean when we refer to a scientific theory as compared to the colloquial use of the term in the chapter “Only a Theory?”
The next two chapters cover breeding, both “artificial” and “natural”, where we get a hint for the power of natural selection acting over many millions of years when we see what can be wrought over just a few centuries in things like dogs and corn. The evidence for this great span of time is addressed in the following chapter, which discusses things like radiometric dating. I need to point out a very minor gripe here, as somebody with some physics training and who has worked with radioactive decays. Dawkins says “The favoured measure of the decay-rate is the ‘half-life’.” I don’t really know what “favoured” means, but though the half-life is a popular measure, it’s not the most natural measure. That would go to the so-called “lifetime”, which is when you’d expect to find 1/e of the original substance, whereas the half-life is 1/2. Minor gripe concluded.
The fifth chapter discusses the long-term experiment by Richard Lenski’s team on E. coli bateria which provides copious evidence for evolution right “Before our very eyes.” Check the Wikipedia page or read the book, because this is just one awesome experiment. Dawkins then goes on to discuss the fossil record and human evolution, the latter part includes a truly cringe-worthy transcript of a discussion Dawkins had with a creationist. As he points out, fossils are a bonus we get when counting up the evidence, the theory does not rest upon them as creationist critics assert. The best evidence is genetic, which he discusses in a later chapter. Before that he also talks about embryology and plate tectonics.
After going through the genetic evidence and the construction of a tree of life, Dawkins points out (as Gould also did) that the best place to look to distinguish creation from evolution is in instances of bad design, like the ostentatiously long larygneal nerve in the giraffe. The penultimate chapter of the book is similar to one from The Blind Watchmaker (which I also recently reviewed) about evolutionary arms races, for example between predator and prey. The cheetah seems exquisitely designed to catch the gazelle, and the gazelle seems exquisitely designed to evade the cheetah. Could the Designer perhaps not make up its mind?
The final chapter is a rather beautiful line-by-line discussion, with asides on topics like the second law of thermodynamics and the origin of life, of the concluding paragraph of Darwin’s On the Origin of Species:
“Thus, from the war of nature, from famine and death, the most exalted object of which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.“