Review of Cowen's History of Life, 6th Edition
Edited by Michael Benton
Supervised translation by Robert Jenkins, translated and edited by Yasushi Kubo
Tokyo Kagaku Dojin Publishing
Issued July 21, 2023
page 304
4,900 JPY (excluding tax)

"The History of Earth's Life" (hereinafter referred to as "this book") is a book packed with very interesting content that covers a wide range of topics related to the evolution of life and the transition of the Earth. In this book review, we would first like you to read an excerpt from the "Preface" written by the authors of this book. By reading this powerful and sincere sentence, which most concisely expresses the significance of publishing this book and the authors' sentiments, we hope to increase the chances that you will read this humble review through to the end.

(Excerpt from the "Preface" below) Why must we think about the past? If we do not understand the past, how can we wisely deal with current problems? ... On this planet, nature has spent 3.5 billion years changing the climate and geography, introducing new life forms, and conducting every possible experiment. If we can read the results of these experiments from the fossil record, we will also be able to understand the limits of the current biosphere. Doing so might allow us to prolong the life of our current biosphere before a catastrophe occurs. (End of excerpt)

The table of contents, presented following the ”Preface” and "Translator's Preface" at the beginning of the book, will help provide an overview of the book's structure, which consists of 23 chapters. The titles of each chapter, as well as the sub-items under each chapter, are presented in brief terms, making it easy even for beginners and readers unfamiliar with the field to grasp the overall picture. Another notable feature of the table of contents is that out of a total of 230 chapter items, 16 items covering "fundamental knowledge for studying paleontology" are highlighted. The contents are as follows: (Quoted from the table of contents below) How to determine the age of fossils? / Use of isotopes in biology / Cladistics / Molecular clock / Biotic communities and biogeography / Air breathing / Amniotes and the amniotic egg / How did herbivory evolve in tetrapods? / Thermoregulation in primitive reptiles / Types of flight / Reasons for the success of angiosperms / Proxies: Understanding paleoclimate / Scientific ocean drilling and proxies / Major classifications of mammals / Island biogeography / Ancient DNA (End of quote). By appropriately following these lists and navigating back and forth between the contents of chapters that spark their interest, readers will gradually become familiar with the worldview of paleontology as an academic field, as well as its fundamental research techniques and methodologies.

The main body of the book consists of 23 chapters spanning 281 pages. Each chapter contains between 8 and 14 pages and is organized into 5 to 17 sections (totaling 230 sections), some of which serve as the aforementioned ”basic knowledge for studying paleontology.” Particularly effective for the reader's comprehension are the headings starting with ”?” that appear directly after each chapter title, just before the beginning of the main text. Each chapter presents 3 to 4 questions or topics for consideration. For example, Chapter 1, "The Origin of Life," presents the following questions: (Quoted below from Chapter 1) After the early Earth cooled, comets and meteorites brought ice (water) and a wide variety of organic compounds. Many researchers believe these were crucial elements in the birth of Earth. The same process must have occurred on Mars, Venus, and even the Moon, so why did life emerge only on Earth? Where on Earth did life originate? Think about this for yourself and explain which scenario is the most plausible, along with reasons and evidence. Since it is impossible to directly observe the living forms of extinct organisms, some might argue that "paleontology is a fantasy." Share your opinion on this claim. (End of quote) To paraphrase these briefly: "Why was life able to emerge only on Earth?", "Where on Earth did the first life originate?", and "Can we truly understand the mechanism of the origin of life through current human activities (research)?" These questions are likely "familiar" ones in a sense—questions that anyone who has ever taken even a slight interest in the Earth, the universe, living organisms, and "being alive"—that is, all of us, without exception, have imagined at some point.

Starting from asking such basic and fundamental questions, this book carefully traces the 4.5-billion-year history of life on Earth. The titles and summaries of each chapter are as follows.
1. The Origin of Life: Gracing the beginning of "Earth's Life History," this chapter addresses fascinating topics that probe the mystery of life's origin. The authors explore the possibility that meteorites and comets provided the building blocks of life after the early Earth cooled. Furthermore, they raise the question of why life originated exclusively on Earth, prompting readers to ponder the answer. Additionally, refutations are presented against the view that "paleontology is fantasy," emphasizing just how important scientific progress is.
2. Early Life: Exploring the mysteries of early life through rocks and fossils. The difficulties of radiometric dating and the hypothetical approach of observing Earth's past evolution from a spaceship are also discussed. This will provide readers with an opportunity to engage their imaginations and consider the evolution of early life while being exposed to scientific methodology.
3. The Birth of Eukaryotes: Focusing on the origin of eukaryotes and their evolution, this section explores fundamental questions regarding biological evolution, such as the concept of species, the advantages of sexual reproduction, and how to handle information from unicellular-like fossils. Readers will be stimulated to think about biodiversity and the mechanisms of adaptation.
4. Evolution of multicellular animals: This chapter discusses the body structure and ecology of Rangeomorphs, ancient organisms that flourished during the Ediacaran period. It also examines mass extinctions and shifts in ecosystems during subsequent evolution. Readers can use this chapter as an aid to understanding the complex intertwining and changes of past ecosystems.
5. Cambrian Explosion: This section focuses on the diverse biota of the Cambrian period and its evolution. Discussions on the bizarre Burgess Shale fauna and the role of biominerals reveal to the reader the complexity and wonder of ancient ecosystems. It also provides information on the relationship between predators and biodiversity, as well as the importance of biominerals.
6. Changing Earth and Life: This section focuses on major shifts in the Earth's history and fluctuations in the diversity of marine life. Discussions on mass extinction patterns and factors influencing biological evolution provide readers with material for deep reflection on the Earth's historical changes and the adaptability of life.
7. Early Vertebrates: This section addresses important questions regarding the evolution of early vertebrates. The evolution of fish, the advantages of air breathing, and the evolutionary process are explained in an easy-to-understand manner, which will help readers comprehend the process of diverse adaptation in vertebrates.
8. Leaving the Water: This section focuses on the adaptive evolution of aquatic organisms as they moved onto land. It provides a deep exploration of the evolutionary processes of both plants and animals, as well as the impact of these evolutionary steps on the global environment. Special attention is given to the rise in atmospheric oxygen concentrations and changes in biogeochemical cycles caused by the terrestrialization of plants.
9. Early Tetrapods and the Origin of Amniotes: This section explores in detail the evolution of early tetrapods and amniotes. It explains the development of fleshy fins, the challenges tetrapods had to overcome on land, and the adaptation of early insects to herbivory, allowing readers to understand the diverse evolutionary processes of tetrapods.
10 Early Amniotes and Their Thermoregulation: Focusing on the evolution and thermoregulation of early amniotes. It discusses the evolutionary processes and adaptive outcomes of amniotes, along with the advantages and disadvantages of thermoregulation, allowing readers to gain insight into the complexity of adaptation in biological evolution. It also touches on the impact of geographical changes on fauna and flora.
11. Mesozoic Marine Revolution: Discusses in detail the Mesozoic Marine Revolution and its impacts. It provides interesting information on changes in marine ecosystems, biological adaptation, and the evolution of marine animals. It also examines the impacts of climate change on marine ecosystems and their connectivity to the Earth as a whole.
12. The Triassic Turnover: Focusing on the Triassic turnover and the evolutionary stage resulting from it. Examples of vertebrate evolution and convergent evolution are featured, which will help readers understand the interaction between ecosystem changes and evolution.
13 Dinosaurs: Fascinating information regarding the evolution, diversity, and extinction of dinosaurs is explored. The gigantism of dinosaurs, the evolution of air-breathing, and the role of feathers are explained, allowing readers to understand the depth of dinosaur ecology and evolution.
14. Evolution of Birds and Flight: Addresses key issues regarding the evolution of birds and flight. Detailed explanations cover patterns in the evolution of flight, comparisons between birds and pterosaurs, and different theories on the origin of avian flight. It offers readers an opportunity to think deeply about the evolution of flight and its impact on ecosystems.
15. The Cretaceous Terrestrial Revolution: This section focuses on changes in Cretaceous terrestrial ecosystems and their impacts. It provides a detailed explanation of the emergence of angiosperms, the diversification of insects, and the accompanying ecosystem fluctuations. It also explores the reasons for the success of angiosperms and other evolutionary factors.
16. The End of the Dinosaurs: Focuses on the causes and impacts of the dinosaur extinction at the end of the Cretaceous period. Different hypotheses, such as the asteroid impact theory and volcanic activity theory, are explained in detail, allowing readers to gain fascinating insights into the mystery of the dinosaur extinction.
17. The Changing Ocean and Climate: Important themes regarding global climate change and changes in marine ecosystems are explored. Information is provided on climate change proxies, the transition of marine ecosystems, and the impacts since the Industrial Revolution, allowing readers to consider the complex relationship between global environmental change and ecosystems.
18. Origin of Mammals: This section focuses on the evolution and characteristics of mammals. It explains adaptations in permanent teeth, cranial and jaw features of mammals, and the differences between marsupials and placentals, which will help in understanding their diverse evolutionary processes. It also discusses the standing of mammals in the Cretaceous period and evolutionary constraints.
19 Cenozoic Mammals: This section focuses on the evolution and diversity of Cenozoic mammals. It provides a detailed explanation of ecosystem reorganization after the extinction of the dinosaurs, biological adaptation, and the origins of modern mammal diversity. It also examines the impact of human activities on ecosystems since the Industrial Revolution, offering readers insight into the relationship between environmental change and biological evolution.
20. Geography and Evolution: This section focuses on the relationship between geographical distribution and evolution. It explains continental drift, the formation of ecosystems, and the interconnectedness of plant and animal evolution, which will help readers understand the impact of Earth's diverse environments on biological evolution. It also examines the impact of human activities on ecosystems.
21 Primates: Focusing on the evolution and characteristics of primates, this section explains their evolutionary process, the diversity of modern species, and their relationship to humans, allowing readers to deeply understand the evolutionary history and diversity of primates. Furthermore, the elucidation of evolution using genetic data and fossil records is discussed in detail.
22 Human Evolution: Focusing on human evolution and its history. The evolution of Homo erectus and Neanderthals, as well as analysis using ancient human DNA, are explained in detail, helping to understand the complexity and diversity of human evolution. It also examines how human evolution is related to geographical factors and environmental changes.
23 Ice Age Organisms: Focuses on Ice Age organisms and their evolution. It provides discussions on the extinction events at the end of the Ice Age, changes in ecosystems, and the causes of extinction. Additionally, it mentions regions and organisms that were less susceptible to the impacts of extinction, exploring fascinating information regarding the biological evolution of the Ice Age.

Following the full text of all chapters are the "References (113 English papers)," "Index (approx. 1,100 words)," and the supervising translator's commentary on the "Cover Art: The Spiral Staircase of the History of Life." This concludes the overview of the book.

For me personally as the author of this humble text, the chapters that intrigue me the most and that I would want to read above all others are the four chapters spanning from Chapter 13, "Dinosaurs," to Chapter 16, "The End of the Dinosaurs." Prompted by exciting questions—such as how dinosaurs represented by sauropods (like Diplodocus, Apatosaurus, and Brachiosaurus) were able to grow to such gigantic sizes, the common and differing traits of birds and pterosaurs as contemporary flying animals, why birds survived the extinction at the end of the Cretaceous while pterosaurs did not, what is believed to have happened as a result of the Cretaceous-Paleogene (K-Pg) mass extinction and meteorite impact, and what the differences were between the organisms that went extinct at the K-Pg boundary and those that survived—each chapter presents fascinating scientific facts and the authors' resulting discussions, even for a dinosaur fan like myself who has almost no academic preliminary knowledge.

In the ”Preface” at the beginning of the book (mentioned above), the authors also write the following: (The following is a quote from the ”Preface”) We have something to tell you. You do not need to accept the interpretations in the book as they are. Unlike "facts" such as the fossil record itself, interpretations and hypotheses are merely opinions. If you come up with an idea better than the hypotheses written in this book, please consider it. First, consult the cited literature. ...The slogan frequently used in the 1960s, "Question Authority!" is still valid today. (End of quote) When faced with a book of such vast and grand scale, we are often prone to remaining uncritical and passive readers throughout. This can be described as a warm, gentle, and encouraging warning from the authors against that tendency. We should read on mindfully, with critical thinking, and with enjoyment.

Through the process of reading and analyzing to write this book review, an old, evocative question resurfaced in my mind: "Where do we come from? What are we? Where are we going?" As many of you likely know, this is the title of a famous painting left behind by the French painter Paul Gauguin, and it is my absolute favorite question. The life science research that I make my living from focuses on various issues surrounding frog eggs (such as morphogenesis, maturation, fertilization, and cell death). However, like all other life science research (or so I personally believe), its purpose is to clarify the origins and future of us humans as living beings. In that sense, this book is not only an excellent textbook for exploring the specialized field of paleontology, but it is undoubtedly a fine book that prompts researchers, students, and general readers with a broad interest in the life sciences to deeply contemplate: "Where do we come from? What are we? Where are we going?" Finally, I would like to conclude this review by quoting a powerful, self-recommending sentence written by the supervisor of the translation in their afterword. I fear this has been a very long and clumsy book review, but I would like to express my heartfelt gratitude to those who have patiently read it. Thank you very much.

(Quoted below from the "Translator's Afterword") I am confident that we have created one of the best books available for learning the history of life and the principles of paleontology. ...For the many people interested in global environmental issues such as global warming and biodiversity, this book will also be useful for gaining an overview of past global environments and life in order to view our current situation objectively. (End of quote)

August 2023
KENICHI, the ultimate dinosaur fan (Kyoto Sangyo University, Faculty of Life Sciences, Department of Industrial Life Sciences)
Kenichi Sato

Book Review: Cowen's History of Life, 6th Edition (PDF file)