We Can Never Go Home: How Becoming an 'Interplanetary Species' Means We Won't Be a Single Race Anymore

What will happen if we succeed and start inhabiting the rest of the solar system’s planets in the long term?

How becoming “interplanetary species” means we’re not a single species anymore
No comments Twitter Flipboard E-mail

We’re alone. I don’t know if we're alone in the universe, but we certainly are on Earth. The past few decades and the rosary chain of Neanderthals, Devinsonians, and homo floresiensis, show there there was a time where there were other human beings on Earth, and that we’re the last ones. But not for long.

One thing is clear: When we become an “interplanetary species,” in the famous words of SpaceX CEO Elon Musk, we’ll take evolution with us. What will happen if we succeed and start inhabiting the rest of the solar system’s planets in the long term? We'll change radically.

Evolution Up There

I'm sorry, the gravity of a real planet hurts

Scott Solomon, a professor of biology at Rice University, wondered what would happen to space colonies over time. “What’s interesting to me as an evolutionary biologist is thinking: What if we’re actually successful?

“I don’t think there has been nearly as much discussion about what would become of the people that are living in these colonies generations later,” Salomon added. And if we exclude things like the colossal sci-fi TV series The Expanse, he’s right. Exposed to environmental conditions radically different from those on Earth, the human genome would undergo a series of mutations.

Solomon has a TED talk where he outlines some of the effects that colonists will likely undergo. The biologist explains that in just two generations, Martians will need glasses for nearsightedness and suffer serious immune problems. Pregnancies and childbirth on Mars will also become more dangerous, the professor stated, and those are just a few of the health issues.

However, those aren't the most striking of Solomon’s ideas. According to the professor, Martians should stop interbreeding with Earthlings after two generations. The long-term survival of Martian communities requires specific biological adaptations—such as those of the Inuit of the Arctic—and genetic mixing with humans on Earth would only delay this process. As such, unity as a species could be detrimental to the adaptive success of extraterrestrial humans.

We’ll Never Go Home Again

Spacecraft launching

For Solomon, even contact between the different communities will be challenging because the anti-pollution protocols would lean towards to creating aseptic spaces in space and depress Martian nervous systems. In this scenario, any contact with the “dirty” Earthlings will be dangerous. (I think he underestimates the ability of microbes to stay with us even when we don’t want them to).

But even if we keep our immune systems strong, pathogens will evolve as fast as we do. It’s unclear whether we would be prepared to fight new diseases. However, the conclusion is that “if we eventually come to inhabit multiple worlds scattered throughout the solar system over time, we may see the evolution of a plethora of new human species.”

We should consider this, especially now that Amazon and Blue Origin founder Jeff Bezos “sees a trillion people living in space” and wants to return to the Moon, “but this time to stay. Meanwhile, Musk is determined to get to Mars. It’s not about making us an interplanetary species; it’s about making new humans.

But in the end, it won't be goodbye. It'll be a "see you later." After all, no one really knows what the future holds.

Related | Artemis: Dates, Plans and Everything We Know About the New Space Mission to Put People on the Moon

Home o Index