Book review – The Earth: A Biography of Life

6-minute read

I have previously jokingly called the “Earth biography” a rite of passage for science writers; many authors try their hand at it at some point. Fortunately, the Earth is big and time is deep, so there are numerous ways to tell this story. Here, it is palaeontologist Elsa Panciroli’s turn. Next to many unusual examples by which to tell the story of life’s evolution, her writing stands out for correcting common misconceptions and for its inspired language.

Panciroli has rounded up the most iconic and important organisms into 47 vignettes. The selection of organisms includes some of the usual suspects; after all, no self-respecting earth biography could do without trilobites, ammonites, or Archaeopteryx. More interesting are the lesser-known representatives of some of life’s major evolutionary transitions. So, as an example of the first animals with a notochord (the precursor of the backbone), she discusses Myllokunmingia found in China rather than the usual example of Pikaia. And as an example of the water-to-land transition of vertebrates, she includes Acanthostega rather than Tiktaalik. When discussing marine reptiles, you learn of Utatsusaurus and the fact (why did I not know this?!) that the evolution of marine reptiles saw terrestrial animals do a U-turn and return to the sea, much like whales would later do.

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Panciroli does her best to balance the coverage and there is a nice spread of vertebrates, invertebrates, plants, and (slightly underrepresented) fungi. That last one comes in the form of Prototaxites, a giant fungus that was initially mistaken for a tree because of its concentric growth rings. What I appreciated is that Panciroli includes groups that are not necessarily always considered eye-catching, but that are keystone species in ecosystems (e.g. earthworms, beetles, bees, grasses, or kelp) or are incredibly important to geologists and palaeontologists as index fossils (e.g. trilobites, ammonites, and microfossils such as conodonts, graptolites, and foraminifera). Index fossils are named thus because they are abundant and diverse enough, and show sufficiently rapid species turnover, that you can use them to define different time periods and determine the relative age of rock layers. Or, as Panciroli puts it nicely: “Most of the rock layers of the Cambrian are marked by changes in trilobites, like a fossil clock ticking through deep time” (p. 42).

“Everyone can name clear examples of living and non-living things. However, as so often in biology, there is no sharp demarcation between the two.”

Beyond interesting facts and unusual animals, what ties it all together and elevates this book is the writing, both on account of the excellent explanations and the beautiful phrasing. I keep returning to good explanations in my reviews as I think this is incredibly important, especially where evolution is concerned. Panciroli again: “[evolution] is a seemingly simple concept […] but encompasses such intricate complexity that it is easily misunderstood and mischaracterized” (p. 12), and this is before we get to the deliberate distortion by some groups. Thus she sets you straight on commonly-heard phrases such as living fossils: “thanks to the process of natural selection, no animal remains static, even if superficially their outer appearance changes very little” (p. 70), or missing links: “an outdated term based on the idea of evolution as a straight line. The reality is much messier, with branches shooting in all directions and often ending in extinction” (p. 162 & 164). Or, particularly common, goal-directed explanations: “Despite the misconception that legs evolved ‘to allow’ animals to walk, this phraseology approaches the process of evolution back-to-front” (p. 88). This was an important theme in Neil Shubin’s book Some Assembly Required: major evolutionary transitions often come about as a result of reusing, repurposing or rejiggling already existing structures and processes. And I could not help but smile at her description of ecosystems, which “can be understood through the flow of energy and materials, which cycle in a pass-the-parcel game through ecosystems via photosynthesis, predation, decomposition and nutrient recycling” (p. 13).

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Her effective explanations are, as in her last book, complemented in places by some particularly inspired writing that describes the K–Pg extinction as “the most famous punctuation mark in our planet’s evolutionary story” (p. 167) and supercontinent formation as “a geological rugby scrum” (p. 109). She injects a degree of poetry that makes you see extinct organisms in a new light. Foraminifera have “survived multiple mass extinctions, and now whisper stories of climate change and environments through deep time” (p. 198), while “In the Jurassic[,] beetles suddenly infest the pages of deep time, munching their way across the landscape and leaving behind a glittering confetti of wing casings” (p. 158). And her description of Archaeopteryx made me want to cheer on this audacious little critter: “At the end of the Jurassic, there lived an animal that was part reptile, part bird, and 100 per cent astonishing […] They are sometimes preserved with a halo of feathers, like snow angels in the rock” (p. 162).

“Everyone can name clear examples of living and non-living things. However, as so often in biology, there is no sharp demarcation between the two.”

Panciroli previously impressed me with her debut Beasts Before Us which covered the evolution of early mammals. The current book is, in some ways, a more challenging one to write; it could have ended up as a random collection of interesting factoids and eclectic tidbits. However, she ties the book together by punctuating the short vignettes with introductions to the different geological periods that stress the connections and interactions between evolution, geography, and geology. There are numerous examples of plate tectonics shaping the whole world: the breakup of Pangaea reproductively isolating animals and plants, contributing to increased speciation; the break-up of Europe and North America causing extensive volcanism that led to the Palaeocene–Eocene Thermal Maximum; and subsequent cooling thanks to mountain-building episodes such as the Himalayan orogeny leading to increased silicate weathering that drew down atmospheric carbon dioxide, the Antarctic Circumpolar Current putting Antarctica in the deep freezer, and the Isthmus of Panama interfering with global ocean circulation by preventing warmer Pacific water from entering the Atlantic.

The book is complemented by a nice selection of period and modern illustrations from various picture libraries, as well as drawings by Grace Varnham, all of which have been rendered in the same two-tone pink-green style for a unified look. If The Earth – A Biography of Life is Panciroli’s trial by fire, then she has passed the test as far as I am concerned. The combination of interesting popular science facts, inspired writing, and a mission to correct common misconceptions make this book easy to recommend, and would make for a great gift.


Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

The Earth – A Biography of Life

Other recommended books mentioned in this review:

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