Ed Yong is one of the most talented science journalists writing today. He has previously won a Pulitzer Prize for Exploratory Reporting for his work documenting the COVID-19 pandemic in articles published in The Atlantic. I have followed his work with pleasure for years.
At the start of a long drive from St. Louis to Austin, I loaded up the audiobook of his most recent work, “An Immense World: How Animal Senses Reveal the Hidden Senses Around Us.” It’s delightful and informative, written with a clear eye, light touch and flashes of humor.
Yong’s method involves interviewing scientists working on animal senses. He goes into the labs and into the field with them, and he offers specific anecdotes of his own interactions with some of the reptiles, mammals, cephalopods, and insects whose senses he describes.
His main concern is to imagine what the sensory worlds of animals look like, their Umwelt, a German word referring to the autonomous sensory environment, or lived environment, of sentient people and animals. Yong also repeatedly references a famous 1974 essay by philosopher Thomas Nagel, “What Is It Like to Be a Bat?” which has been described as the most widely cited thought experiment on consciousness.
The book is organized in chapters around different senses: smell, taste, sight, heat, touch, pain, hearing, surface vibrations, echolocation, electric and magnetic fields.
It begins with the related senses of smell and taste, describing, for example, how a snake’s forked tongue senses its surroundings, followed by a personal description of a walk with its dog. The chapter on surface vibrations was fascinating. Tiny insects create rhythms on plants that can be picked up by microphones.
Perhaps the best chapters in the book are the two on vision. Eagles and vultures tend to crash into wind turbines because their eyes look down, not forward. Most mammals, like dogs, have two types of cone cells in their retinas that allow them to see color, but not as well as most non-colorblind humans. Most of us, like most primates, are trichromatic, meaning we have three types of colored cone cells in our eyes.
Three types of cones allow us to see the world in color, but most fish and many birds can see many more colors than we can because they have four types of cones in their retinas. They can see colors in ultraviolet wavelengths that we cannot. Many species in which males appear indistinguishable from females do not look like this in the ultraviolet.
Fascinatingly, a small number of women are tetrachromatic. They usually don’t even realize that they can see colors better and perceive color combinations better than the rest of us can. Yong fancifully calls these colors “rurple, grurple, and yurple.”
The eyes evolved independently up to 40 times. Yong focuses on the mantis shrimp’s unusual eyes which give it polarized vision. It also tells us that although some creatures like eagles have much sharper eyes than ours, humans have greater visual acuity than most species.
We learn a lot here, and how we know it. We can try to imagine, imperfectly, the world as it is perceived by living beings by looking at their sensory organs, their behaviors, their bodies, their environments and their evolutionary histories.
It ends with a plea to restrict lights and sounds that interfere with the natural world, which is bigger than we realize.
Yong inspires imagination and wonder at Creation. It reminds us that we are the only species capable of imagining the Umwelten of other animals. This book on the perceptual senses expands our moral senses.
– Frank T. Pool is an award-winning columnist and poet who grew up on Maple Street in Longview and graduated from Longview High School. He is a semi-retired teacher living in Austin. FrankT.Pool@gmail.com.