book review: This Is Life by Christophe Galfard

⭐️ ⭐️ ⭐️ ⭐️ ⭐️ 5/5

Thank you University of Chicago Press for providing an ARC for review consideration via NetGalley! All opinions are my own.

This Is Life was my first introduction to theoretical physicist Christophe Galfard - a former graduate student of Stephen Hawking - but it won't be my last! It took Galfard eight years to write this volume, which is not surprising since it is packed with information presented in such a thoughtful way.

Parts one through three cover evolution, earth's history, and various mass extinction events. The last two parts discuss our likely origin story and the potential for extraterrestrial life. These areas are my jam so I could have had the entire book revolve around just these topics and been completely fulfilled. Yet the book is about life so, while not my favorite topics to learn about, the center part importantly dives into DNA, RNA, nucleic acids, and the like.

Galfard illustrates the extreme fragility and precise conditions required for life with jaw-dropping historical facts. For example, the fifth mass extinction (which wiped out the dinosaurs) was actually the weakest one. By contrast, a separate volcanic event lasted tens of thousands of years, burying an area six times the size of the UK under 2.5 kilometers of lava. During the Cryogenian ice age, the planet froze from pole to pole into a giant ball of ice for 100 million years. Meanwhile, tectonic plates shifted continents at a slow 3mm a year—a reminder that our planet is never stagnant. Earth's tumultuous past is filled with extinct species, extreme climates, glaciations, and meteor impacts. It proves that nothing looks the same as it did then, nor will the future look like today. Evolution even gives species latent abilities they might never use unless a specific need arises. Remarkably, we still share common ancestors and DNA with all species—even fruit flies and bananas—and with organisms living by deep undersea hydrothermal vents, the future of life remains excitingly unpredictable.

Galfard’s approachable style mirrors Carl Sagan; reading it feels like chatting with the author or attending an intimate lecture. He seamlessly layers facts with memorable stories to prevent information overload. Best of all, he injects a soothing, almost ASMR-like tone, inviting readers to pause, breathe, and imagine themselves inside deep space, on Earth, or within the human body.