Chapter 1: The Quest for Extraterrestrial Life

Humanity's pursuit of extraterrestrial existence has captivated us for millennia. This fascination significantly influenced my academic journey; during my undergraduate years in microbiology, I dedicated two years to a research lab focused on discovering and classifying life beyond our planet. Our team, led by a Principal Investigator, grappled with fundamental queries: Will alien life forms be microscopic, akin to Earth's bacteria or fungi, or will they be completely alien in appearance? How can we determine if we’ve encountered life from another world? What might these beings look like, and how would they communicate or move?

For answers to such compelling questions, look no further than the engaging and well-researched book, The Zoologist's Guide to the Galaxy: What Animals on Earth Reveal about Aliens — and Ourselves (Viking Press, 2020). Authored by zoologist Arik Kershenbaum, a lecturer at Girton College, University of Cambridge, this book posits that the same physical laws we understand on Earth apply universally. Just as gravity operates throughout the cosmos, the principles of biological evolution do too, regardless of reproductive methods. Thus, similar to how physicists can predict gravitational behavior on other planets, Kershenbaum suggests we can extrapolate evolutionary patterns elsewhere.

Chapter 2: Predicting Alien Life Forms

While we may not know precisely what extraterrestrial beings will resemble, we can make educated guesses about their potential modes of movement, communication, and social interaction in imagined extraterrestrial environments. In this enlightening text, Professor Kershenbaum delves into a spectrum of conceivable alien life, asserting that the diverse adaptations found on Earth can inform our understanding of life on other worlds.

Drawing inspiration from Earth's electric fish that utilize electrical impulses for hunting, mating, and social interaction, we can envision planets where such signals dominate communication. Alternatively, considering Enceladus—one of Saturn’s fascinating moons, believed to harbor a vast ocean—we might imagine life forms akin to Earth's squids, which use vivid colors to convey complex messages.

Despite the audacity of our hypotheses regarding alien life, the scientific inquiries stem from a profound comprehension of the biological principles that govern all life on Earth: the evolution of life itself, the necessary biochemistry, and the essential environmental conditions.

In a discussion with Louis Gross, Arik Kershenbaum elaborates on the key themes of his book and the scientific basis for imagining alien life forms.

Chapter 3: Communication Beyond Earth

Kershenbaum employs humor to make complex ideas accessible to a broader audience. For instance, he uses characters from Winnie the Pooh to illustrate the flexibility of language, showcasing how a limited set of words can convey infinite meanings. His insights into extraterrestrial communication are particularly enlightening, suggesting that advanced civilizations might rely on vocal rather than scent-based communication.

Perhaps the most thought-provoking aspect of Kershenbaum's work is the exploration of how discovering intelligent alien life might redefine our understanding of personhood. He provocatively questions whether we might consider such beings human if they possess intelligence comparable to ours. Personally, I find terms like "sentient beings" or "nations" more fitting, as "human" specifically refers to our species, Homo sapiens.

In this YouTube video, Kershenbaum further discusses the implications of his findings and the fascinating intersection of zoology and astrobiology.

A Profound Read for Science Enthusiasts

This intriguing book is a must-read for anyone captivated by the science behind science fiction. Whether you're a student, a professional in another scientific field, or simply a curious mind looking to grasp the significance of natural selection in explaining Earth's biodiversity, The Zoologist's Guide to the Galaxy is an essential addition to your reading list.

Note: A hard copy of this book was provided by the publisher for an unbiased review. As an Amazon Associate, I may earn small commissions from qualifying purchases made through links in this article.

Originally published at Forbes.com on January 28, 2022.