The Story of Evolution in 25 Discoveries The Evidence and the People Who Found It

After three previous books in this format on fossils, rocks, and dinosaurs, geologist and palaeontologist Donald R. Prothero here tackles the story of evolution in 25 notable discoveries. More so than the previous trio, this book tries to be a servant to two masters, resulting in a mixed bag.

Prothero has organised The Story of Evolution in 25 Discoveries in a logical fashion. After convincing the reader that the universe and our planet are, indeed, really old, he considers some of Darwin's lines of evidence for evolution, followed by several great transitions in evolution as revealed by the fossil record, more recent evidence from genetics and molecular biology, and, of course, evidence for the evolution of humans.

As in his previous books, Prothero manages to dig up some remarkable stories. For example, Darwin initially mistook the finches on the Galápagos for wrens, blackbirds, and other species. Only when he handed them to the famous ornithologist John Gould for a second opinion did it become clear that these were all finch species adapted to local conditions on the different islands. It later fell to others such as Peter and Rosemary Grant to do the long-term studies that elevated them to the icon of evolution they have become. Meanwhile, Othniel Charles Marsh's monograph on primitive birds that still had teeth was unexpectedly branded a waste of taxpayer's money when US congress was looking for excuses to cut funding to the US Geological Survey in the 1890s.

In many places, Prothero is careful and balanced in his coverage. He highlights the contribution of the historically overlooked Alfred Russell Wallace who independently stumbled on the idea of natural selection after Darwin had already been labouring on it for decades. And while Ernst Haeckel was accused of fraud over his famous drawings showing the embryonic development of different vertebrates, Prothero explains how there is a kernel of truth to Haeckel's claim that ontogeny recapitulates phylogeny, even if "he may have been a bit overzealous in his drawings" (p. 69). On Jean-Baptiste de Lamarck and his ideas, Prothero clarifies how there was much more to him than the caricature of the "guy who got evolution wrong" (p. 198) that he became.

There are classic topics such as convergent evolution, the evolution of the eye, and Lynn Margulis and her theory of endosymbiosis. The relatively young branch of evolutionary developmental biology and the discovery of Hox genes showed that, actually, yes, nature does make leaps and does not always result in slow and gradual changes. Throughout, Prothero repeatedly reminds you that the evolutionary relationships between organisms are like a bush, and not a linear progression from primitive to more advanced creatures. He explains that evolution does not always result in perfect adaptations – they only have to be good enough to help in producing the next generation. And he points out that natural selection can only ever work with the material at hand, resulting in many jury-rigged contrivances, including in humans.

Now, Prothero is also a noted sceptic. A good deal of this book has the secondary aim of showing that creationism is an utterly flawed idea and that the evidence for evolution reveals no traces of intelligent design whatsoever. The thing is, he already did this exercise in Evolution: What the Fossils Say and Why it Matters, so does it need repeating? He spends no fewer than seven chapters here on examples of transitional fossils that provide a detailed picture of fish leaving the water, whales returning to it, birds evolving from dinosaurs, giraffes evolving longer and elephants longer trunks, horses losing their toes and snakes their legs, and turtles acquiring shells. You almost get the feeling that he just cannot help himself.

I have few gripes with the topics that Prothero chose to include here, but I felt somewhat disappointed by all the topics he left out as a consequence of this secondary mission. Two notable omissions are the process of domestication, even though Darwin used numerous examples of it in On the Origin of Species and then wrote a separate book about it. The same is true for Darwin's other big idea: there is no mention of sexual selection, sperm competition, or mate choice.

Beyond these, there is little on speciation and biodiversity, the formation of higher taxa, or the difficulty with species concepts. Epigenetics is mentioned, but not by name. The textbook example of the peppered moth is included, but there is no further discussion on camouflage, mimicry, or warning signals. Richard Dawkins has to make do with two brief mentions, but there is nothing about the different levels of selection, whether selfish genes or group selection. And I am sure Prothero could have beautifully explained the difference between the modern and extended syntheses.

The focus on convincing the reader of the evidence against design raises the question of who this book is written for. For evolutionary biologists like myself, Prothero is preaching to the choir, while creationists are unlikely to pick this book up. The best this might achieve is to remind biologists of the evidence for evolution if we ever find ourselves debating creationists.

Prothero is a fantastic science communicator, and I really enjoy this format of 25 vignettes by which to examine the many facets of a topic. The material that he did choose to include is written with verve and balance. In my opinion, however, the dual motive underlying The Story of Evolution in 25 Discoveries means that he left out many relevant topics and has written a book of narrower focus than the title might suggest.