A History of Life in with inorganic minerals. The study of early A History of Life in 100 Fossils is 100 Fossils life is not easy. historical in placing interesting fossils An indisputable signature of early where they belong in time, but it also By Paul D. Taylor and life occurs in the form of fossilized describes the interactions between these Aaron O’Dea stromatolites. Still found today, animals and their place in the environment: stromatolites are formed by microbial introducing arms-race escalation, NATURAL HISTORY communities that now include continental drift, dwarfing, extinction, MUSEUM, LONDON: microbes capable of oxygen-producing flight, geographic refuges, life habits, 2014. 224 PP. £20.00 photosynthesis. Similar communities are living fossils, mass mortality, parasitism, recognizable on an early Earth, possibly parental care, predation, preservation, as far back as 3.5 billion years. More punctuated equilibria, return to the sea, ife is a miracle relived when every child advanced organisms appeared much later, sexual selection, stratigraphic correlation, is born. We take life for granted. It is at 600 million years or so, in the Ediacaran survivorship, swimming, symbiosis, Leasy to imagine life now to be what biota. These soft-bodied impressions — symmetry, vision, and other intriguing it was in the beginning and what it ever found not only in Australia, but also in a subjects along the way. Small mistakes are shall be, world without end. But our Earth few select locations including England, inevitable when authors cover so much tells a different story, a story of unceasing Namibia and Canada — are generally material, and I saw a few in the subjects I evolutionary change. Life appeared very regarded as multicellular animals but there know best. These are minor, and I found long ago, and was very simple — so simple are competing interpretations, too. myself wondering if they were cleverly that we have difficulty recognizing life in Moving into the Phanerozoic eon — deliberate to engage the attention of experts its earliest forms. How did we get from the the ‘time of abundant life’ — signs of life (for example, on page 116, is ‘survival of the beginning to where we are now? That is the become clearer, but the history reflected fittest’ really Darwin’s phrase?). story of this book. by these signs becomes more complicated. Each illustration of a fossil is A History of Life in 100 Fossils looks like The Phanerozoic started with the Cambrian accompanied by an engaging essay a coffee-table picture book — which it is, explosion, when animals with mineralized explaining what is interesting about the with wonderful illustrations — but the book skeletons appeared more or less everywhere. fossil or how the fossil sheds light on a is also much more: one hundred stepping This early burst of diversification resulted in bigger question. The book could easily stones from the Earth’s deep-time past to its the emergence of representatives of most of serve as a self-guided overview of the fossil shallow present, each artfully illustrated by the animal phyla living today. record, or as a valuable source of visual an iconic fossil. There were in fact billions Eighteenth- and nineteenth-century material and text for a formal course in of steps in an uncountable number of study of the fossil record led to recognition palaeontology. The fossil record is more evolutionary lines, many still unknown. But of successive Palaeozoic, Mesozoic, and complicated and even more interesting than one hundred steps in a few of these lines are Cenozoic eras within the Phanerozoic, can be represented by 100 fossils, but this is enough to engage us as readers and give us filled with ancient, middle, and recent a great place to start. a sense of how life has changed through the animals, respectively. And thus the Human lives are short. The scale course of time. geological timescale was born. Radiometric of geological time and the ubiquity of The book starts in Australia with calibration in the twentieth century told us evolutionary change are thus sometimes fossilized filaments described from the the Palaeozoic ‘era of trilobites’ began about hard for people to grasp, but the evidence 3.5-billion-year old Apex Chert. These 540 million years ago, the Mesozoic ‘era of is preserved in the rock and fossil record filaments are so small they cannot be dinosaurs’ started about 250 million years on every continent. The history of life is seen with the naked eye. They were ago, and the Cenozoic ‘era of mammals’ one of unceasing change, slow or fast, and first interpreted as photosynthetic blue about 65 million years ago. Further, we now the change will undoubtedly continue. bacteria — known as cyanophytes — but know these eras were discrete, separated Keep in mind as you read and enjoy the not surprisingly subsequent authors have by catastrophic extinction events that were photographs that it is a miracle we know argued that they are hairline fractures filled followed in turn by bursts of new diversity. anything at all about the history of life. It is a blessing that we have fossils like the ones illustrated here. These are the classics, but also remember that beautiful and informative fossils are being found all the time. ❐
REVIEWED BY PHILIP D. GINGERICH
Philip D. Gingerich is in the Department of Earth and Environmental Sciences and Museum of Paleontology, University of Michigan, Ann Arbor, Michigan 48109, USA.
© TRUSTEES OF THE NATURAL HISTORY HISTORY OF THE NATURAL © TRUSTEES LONDON MUSEUM, e-mail: [email protected]
2 NATURE GEOSCIENCE | VOL 8 | JANUARY 2015 | www.nature.com/naturegeoscience
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