The two most fascinating questions about extraterrestrial life are where it is found and what it is like. In particular, from our Earth-based vantage point, we are keen to know where the closest life to us is, and how similar it might be to life on our home planet. This book deals with both of these key issues. It considers possible homes for life, with a focus on Earth-like exoplanets. And it examines the possibility that life elsewhere might be similar to life here, due to the existence of parallel environments, which may result in Darwinian selection producing parallel trees of life between one planet and another. Understanding Life in the Universe provides an engaging and myth-busting overview for any reader interested in the existence and nature of extraterrestrial life, and the realistic possibility of discovering credible evidence for it in the near future.
1. The search for extraterrestrial life
2. Where in the universe to look?
3. Evolution – here and elsewhere
4. The key concept of habitability
5. Life in the solar system
6. Life in other planetary systems
7. The nature of extraterrestrial life
8. Intelligence – here and elsewhere
Summary of common misunderstandings
References and further reading
Wallace Arthur is an evolutionary biologist with an interest in how life evolves on other planets, and in particular how similar the life forms that evolution produces on one inhabited planet may be to those on another. He is the author of The Biological Universe (Cambridge University Press, 2020) and Understanding Evo-Devo (Cambridge University Press, 2021).
"A fascinating overview of life on Earth and the prospects of finding parallel forms of it on habitable exoplanets. Wallace Arthur provides an engaging, yet scientifically accurate, overview of the current knowledge and what to expect from the next Copernican revolution looming on the horizon of astronomy."
– Avi Loeb, Professor of Science, Harvard University, USA
"From the origin of the universe through to the search for oxygen biosignatures on exoplanets, this book is a marvellous and broad introduction to our efforts to find out if this fascinating replicating material we call life is to be found elsewhere in the universe, and where we might find it. It will appeal as much to a professional seeking a good review as to the layperson wanting an introduction to the subject."
– Charles Cockell, Professor of Astrobiology, University of Edinburgh, UK
"Beginning with a guided tour of life on Earth, Wallace Arthur reaches out to explore the possibility of alien life deep in the cosmos. In this provocative but scientifically argued treatise, he describes what form such life might take and the technological means by which we might discover it. A thoughtful and riveting read that excites like science fiction yet rests on science."
– Addy Pross, Emeritus Professor of Chemistry, Ben Gurion University of the Negev, Israel
"A tremendously broad and comprehensive look at the whole panoply of issues surrounding our search for extraterrestrial life. A very useful text for anyone just starting on an exploration of the possibilities of life in the universe."
– Arik Kershenbaum, University of Cambridge, UK, author of The Zoologist's Guide to the Galaxy