The brilliant, Pulitzer-prize-winning science writer, Ed Yong, has just published his latest book: An Immense World: How Animal Senses Reveal the Hidden Realms Around Us. I've only just started reading it, but it is living up to his reputation so far.
In the first few pages, he introduces the reader to the intriguing concept of "Umwelt." It is a German word put into use in 1909 by a German zoologist whom Yong describes as having defined it as "…specifically the part of [an animal's] surroundings that an animal can sense and experience –– its perceptual world." Yong tells us that the world presents living organisms with countless physical stimuli, for which most creatures, including humans, can only sense and interpret a few. This restricted experience of reality creates a sort of "sensory bubble" that is the umwelt of a particular creature.
As an example, the umwelt for birds and bees includes the ability to see ultraviolet light, which we humans cannot see. Birds can detect Earth's magnetic field and use it to navigate migrations that can be thousands of miles long. Did you even know that Earth had a magnetic field? If you know that, it is because you read about it in a book and not because you ever felt it, because you can't. Snakes can "see" the infrared radiation given off by other animals, but we can't unless we have night-vision goggles. The list of senses we don't have is long, which is not to suggest that evolution short-changed us. Yong points out that no creature can sense every stimulus, which would be overwhelming if it did.
We have, as humans, a remarkable sensory system that gives us a rich experience of our world. Yong wants us to understand that all animals have rich sentient lives that are often quite different from ours because they can experience phenomena that we cannot detect. It is not an issue of which species has the best sensory apparatus but rather an issue of recognizing and respecting the diversity of conscious experience. There are observable differences in the sensory capabilities between species, but individuals within every species will have subtle genetic differences in sense organ receptors. This genetic variability creates a situation where every individual umwelt, even within a species, is at least somewhat unique. In a world filled with perhaps hundreds of billions of sentient beings, every perceptual experience is one-of-a-kind.
Yong, whose writing is sublime, says about the senses: "The senses transform the coursing chaos of the world into perceptions and experiences––things we can react to and act upon. They allow biology to tame physics. They turn stimuli into information. They pull relevance from randomness and weave meaning from miscellany. They connect animals to their surroundings. And they connect animals to each other via expressions, displays, gestures, calls, and currents."
In his introduction, Yong uses a quote from Henry Beston; it is probably my favorite quote from nature writing in a lovely book about nature that I've read more than once: The Outermost House, published in 1928. Beston lived for a year in a small cabin on Cape Cod and observed the animals and people around him, especially the birds. In chapter two of The Outermost House, entitled Autumn, Ocean, and Birds, Beston writes, "We need another and a wiser and perhaps a more mystical concept of animals." Getting started on Yong's book about sensory biology gives me a new way of thinking about Beston's nearly century-old observations. The expanding research in the field of sensory biology that Yong is writing about seems to support Beston's intuitions. The quote from Beston that Yong uses always makes me choke up a bit when I read it: "…the animal shall not be measured by man. In a world older and more complete than ours, they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear. They are not brethren, they are not underlings; they are other nations, caught with ourselves in the net of life and time, fellow prisoners of the splendour and travail of the Earth."
Humans have created a global culture centered around acquiring money and power without regard for the consequences this quest might have on the nature that makes our existence and our experience of that existence possible. We can do better. Ed Yong's book will be a valuable guidebook for those who want to do better.
I expect as I continue reading Mr. Yong's book, I will want to write more blog posts about it.
Monte