Becoming Martian is an inspiring deep dive into how humans might live, thrive and conceive future generations on Mars.
But it also explores how those humans could grow to regard the Red Planet as their home, underpinned by evolutionary changes wholly incompatible with life on Earth.
Evolutionary biologist Scott Solomon expertly guides us through the technical, biological, social and psychological minefield facing the first Mars settlers, challenges that could transform us not just into a multi-planetary species, but perhaps a different species altogether.
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The book examines the Chicxulub impact that obliterated the dinosaurs 66 million years ago, raising a ‘when, not if’ likelihood that a similar event could precipitate our own demise.
Solomon considers three hypothetical evolutionary trajectories: we remain as we are; we go extinct; or we evolve into something different, “a new type of human”.
And that tantalising third option is the driver of this book.
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Solomon argues that humans leaving Earth for Mars may bring about an evolutionary ‘splitting’ of the species.
The Red Planet’s low gravity, a third as strong as Earth’s, could yield future humans that have weaker bones and muscles, less pronounced foot arches, different sweat glands and maybe new skin pigments that guard against Mars’s extreme radiation.
He considers that life in underground Mars habitats, tightly climate-controlled, could lead to reduced tolerances to the microbial diversity we are used to here on Earth.
Asthma, type-1 diabetes and even eczema, Solomon ponders, could sit among a raft of conditions that might prove highly common in future Martians.
The book sets its discussions against our growing corpus of Mars knowledge and how we’ve learned to live and survive away from Earth.
Solomon closes with his personal desire “to remain here, along with my fellow humans, on the planet of our ancestors”.
Yet Becoming Martian is a thought-provoking reminder that evolution may be far from done with us and that perhaps our most fundamental change of all could still lie ahead.
We got the chance to speak to Solomon and ask him about what lies ahead for a humanity that becomes truly interplanetary.
Is our becoming an interplanetary species either inevitable or necessary?
"There are many motivations for living on other worlds, whether it’s the moon, Mars, or elsewhere. Some see potential profits, some want the thrill of adventure and discovery, while for others there are geopolitical forces at work.
Ultimately, we may be driven to become interplanetary as a way to avoid extinction: at present we have all our eggs in one planetary basket, which makes us vulnerable to major disasters like nuclear war or a large asteroid impact."
How would a child born and growing up off-Earth be different from their terrestrial ancestors?
"We know very little about whether human reproduction is affected by conditions on the Moon and Mars like lower gravity and higher radiation. If children were to be born on other worlds, they would likely grow and develop in different ways.
Muscles and bones respond to gravity, and both could be weaker. The immune system could be affected by developing in an environment that lacks the rich microbial diversity of Earth. These effects could make it difficult or even impossible for a child born and raised on another celestial body to visit Earth."
What are the key ways evolution might alter a space-faring humanity over time?
"Plants and animals that become isolated on islands evolve through forces like natural selection and genetic drift. The same forces would affect future generations of people living in space settlements. The number of initial settlers, and the genetic diversity they represent, would have a large effect on how well natural selection to the new environment would lead to adaptation.
The less interaction there is between people living on different planets, the more rapidly they would evolve in different directions."
Are there solutions to the practical issues that would arise if we wanted to send long-duration crewed missions to the nearest stars and exoplanets?
"Visiting other solar systems would require spending more than one human lifetime on a spacecraft. If that were possible, children could be born and raised in space and might spend their entire lives there. Generating artificial gravity would likely be necessary to avoid serious health consequences. They would need to grow their own food and recycle all water, nutrients, and materials.
Another alternative would be to use hibernation or cryogenic preservation to all individuals to survive the long journey and be awakened once the ship arrives. While researchers are exploring some of these ideas, we are a long way from having this type of technology. For now, we should focus on figuring out how to love on the Moon and Mars."
Becoming Martian by Scott Solomon is published by MIT Press
