Science fiction has provided a galaxy’s worth of depictions of aliens, from cuddly animal-like creatures such as Baby Yoda to sagacious humanoids like Mr. Spock. What’s lacking, though, are representations of extraterrestrials based on actual scientific principles.
That’s where Arik Kershenbaum comes in. An Israeli-educated zoologist now at the University of Cambridge, Kershenbaum argues that we can and should consider aliens from a new perspective — the evolutionary biology reflected in all creatures great and small on Earth. He’s sharing this perspective in a new book, “The Zoologist’s Guide to the Galaxy: What Animals on Earth Reveal About Aliens — and Ourselves.”
“Most of the concepts I deal with are very firmly based in evolutionary theory here on Earth,” Kershenbaum told The Times of Israel. “It did not take a lot of radical new theories to put it together.”
But it did take Kershenbaum applying what he has learned from studying animals in the wild — including rock hyraxes and dolphins in Israel, and wolves in the western United States.
Kershenbaum wondered whether the varying pitches of wolf howls constitute a complex language, one based on sounds and not words. That got him thinking about the radio signals from outer space received by the Search for Extraterrestrial Intelligence (SETI). As SETI analyzes these signals for evidence of an alien response, Kershenbaum asks whether such a response might come in an unexpected format — just as the sound-based communication of wolves challenged his idea of what represents language.
Kershenbaum said that “the main driver for the book” is the kind of work he does, “looking at the evolution of all kinds of traits in animals — not just communication, but everything animals do.”
“In the last 50 years, we’ve had really good evolutionary models of how all life evolved and became more complex. Evolutionary rules are universal rules not specific to Earth. They can apply everywhere, a natural extension of why things are the way they are on Earth,” he said.
The early chapters of the book address “what you might think of first [regarding] alien life,” Kershenbaum said. “What they look like, how they move, things like that. It’s heavily constrained by physics and the laws of mathematics.”
Later, the book explores what he calls “[the] more interesting question that people really want answered,” namely, “How much are [aliens] going to be like us? How likely will alien life be anything like us?”
In the book, Kershenbaum considers similarly provocative questions such as alien sex, reproduction and death. Of this last subject, he said, “there’s not a great deal of sci-fi. It’s a slightly morbid topic.” He also discusses possibilities for humanoid aliens and extraterrestrial artificial intelligence (AI).
How much are aliens going to be like us? How likely will alien life be anything like us?
Describing the book as “a popular science book,” he notes that overall, “very little has been written about this,” but adds, “a lot has been written on different elements of evolutionary theory,” from Richard Dawkins to “really thoughtful sci-fi.”
On the origins of alien species
For Kershenbaum, it all goes back to Charles Darwin. His rescue dog is even named after the theory of evolution’s founder.
“Up until Darwin, we humans didn’t realize that all life was related,” Kershenbaum said. “If you follow things back far enough, there’s a connection between any two individuals from any species. Without that, we can’t understand how life evolved, how complex life evolved.”
If you follow things back far enough, there’s a connection between any two individuals from any species
Billions of years ago, all life on Earth shared a last universal common ancestor, or LUCA, for short. Yet as organisms faced challenges such as how to obtain food, some survived by evolving to meet these challenges, outlasting rivals while becoming more complex. Consider the nuanced behavior of the rock hyraxes Kershenbaum has studied.
“They’re everywhere in Israel,” he laughed. “You barely need to go out of your house.”
Instead of competing against each other for food, they cooperate. One altruistic individual stands guard against predators while the others forage.
“When there are challenges to be faced — difficulties and adversity when food is short and it is difficult to live your life — any and every opportunity will be exploited,” Kershenbaum said. “Organisms will adapt themselves.”
And, he said, “If the problems animals face on Earth are similar to difficulties other planets will have, and there aren’t an infinite number of solutions to particular problems like getting energy from the sun and stars, planets will tend to evolve similar solutions to similar problems on different planets.”
The book examines two intriguing moons of Saturn — Titan and Enceladus. Both have the liquid that is necessary for chemical reactions that will produce life, yet in each case, the circumstances differ dramatically from Earth. On Enceladus, liquid is present as an underground ocean beneath a thick surface crust of ice. Titan, conversely, has liquid on its surface, but in the form of liquid natural gas, specifically methane and ethane.
Noting the particularly unusual conditions on Titan, Kershenbaum said, “That’s a really good reason to go there and investigate. There may be mechanisms we are not aware of, biochemistry we’re not familiar with.”
Kershenbaum is willing to think creatively about how life may arise elsewhere in the universe. Here on the blue planet, many marine organisms live on the ocean floor and go up to the surface to feed. For any life in Enceladus’s ocean, maybe it’s the other way around, with the crust of surface ice serving as the sea floor in this scenario. Kershenbaum is also resourceful in thinking about alien communication. Maybe, he said, extraterrestrial conversation could occur through such diverse ways as sound, light and chemicals, even magnetism and electricity.
“There could be other planets where electricity and magnetism are very common,” Kershenbaum said. “We can look at life on Earth that does use electricity [such as cephalopods]. We can use this to understand why, where and how it could be [used] on other planets.”
Data versus Spock
Part of the book considers more complex forms of alien life such as humanoids and AI. Kershenbaum argues that we shouldn’t confuse humanoids with humanity — and that we shouldn’t assume that something non-biological like AI is outside Darwin’s laws.
Regarding humanoids vis-a-vis humanity, Kershenbaum said, “If we discover an alien species almost exactly like us,” it would “not be related to us at all, no genetic relationship whatsoever. Would you feel comfortable calling them human? They would not be Homo sapiens.”
“I suppose the core of the book is the question, what is humanity?” Kershenbaum reflected. “We know [humanity] won’t be related to any alien species. The brilliance of Charles Darwin was to understand that every individual on the planet is related to every other, no matter what species. It does not apply to aliens.”
I suppose the core of the book is the question, what is humanity?
He made a similarly bold point in thinking about extraterrestrial AI.
“Just because it’s AI doesn’t mean it’s exempt from evolution,” Kershenbaum said. “It does not mean it’s exempt from competing for limited resources. It must be that resources are always limited. [AI] would have similar evolutionary processes — not the same, they are not biological — but you would still see competing AIs.”
He adds that AIs might evolve to not only compete against each other for limited resources but also cooperate with each other for these resources. Maybe they wouldn’t be that different, in this regard, from the altruistic rock hyraxes of Israel.
Some fear that aliens, in whatever form, would be anything but altruistic toward humanity. One adherent to this belief is theoretical physicist Michio Kaku.
“Michio Kaku said it was a terrible notion to contact aliens, they would come eat us,” Kershenbaum said. “It’s a quite popular idea. I don’t hold with that… Any civilization that has the technology to travel between stars, far, far beyond anything we can imagine, will have no need to conquer us, dominate us, eat us.”
“We don’t pose a threat to any alien civilization that will be as full of scientists and engineers as us,” Kershenbaum said. “They will be just as interested in us as we are in them.”
At least for humans, interest is on the rise.
“Scientists genuinely believe we are not far away from discovering signs of extraterrestrial life,” Kershenbaum said. “It means we are starting to raise questions we don’t talk about enough… ‘What does it mean to be an alien? What would our relationship be like? How should we treat, look at, think about them?’ It requires us to think about alien life the same way we think of life on Earth.”
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