What Earth creature is best-suited for space travel? If you said the one with the smartest brain and opposable thumbs, you’d be half right. If you said the eight-legged one that looks like a micro-sized water bear, is found thriving in the most hostile environments on the planet, and has already survived in the vacuum of outer space without the benefit of a million-dollar space suit, you’d be half right as well. Researchers are seriously studying ways to combine human and tardigrade DNA to create a radiation-resistant hybrid to colonize Mars. Will their spacesuits need more legs?
"If we have another 20 years of pure discovery and mapping and functional validation of what we think we know, maybe by 20 years from now, I'm hoping we could be at the stage where we would be able to say we can make a human that could be better surviving on Mars."
While humans might visit Mars before 2039, that date is well-within the projections for setting up a permanent settlement there, and it’s the survival of those humans Chris Mason, a geneticist and associate professor of physiology and biophysics at Weill Cornell University in New York, is focused on. In a presentation at the 8th Human Genetics in NYC Conference, Mason talked about what he learned as a member of the NASA team studying the twin astronauts Mark and Scott Kelly and how his physiology changed after Mark spent a year in space. That research highlighted the damaging effects of cosmic radiation on the human body. In an interview with Space.com after his presentation, Mason discussed his radical idea for gene-splicing human cells with the mighty tardigrade.
“Genetically editing humans for space travel would likely be a part of natural changes to the human physiology that could occur after living on Mars for a number of years, Mason said. "It's not if we evolve; it's when we evolve," he added.”
The way Mason sees it, putting humans in space in large numbers would trigger the usual survival-of-the-fittest evolutionary changes to their physiology, one of which would be that the survivors would have slightly more radiation protection which would be passed down to their offspring and grow stronger over generations. By genetically altering humans ahead of time, that evolution would be accelerated artificially. The real question is … would natural evolution create a human with tardigrade characteristics like Mason and other researchers want to create themselves?
Here’s another question. Despite the tardigrade’s universal survivalist body, would a human-tardigrade hybrid lose its ability to survive on Earth? Would these hybrids be doomed to die on Mars and never return to Earth?
"In terms of a question of liberty, you're engineering it [a future human] to have lots more opportunities, again assuming we haven't taken away opportunities. If we learned that, in some way, when we decided to try and prove the ability of humans to live beyond Earth, and we take away their ability to live on Earth, I think that would be unjust."
Unjust, yes. However, if we’re talking human ethics, we know from past experience that human profits influence human ethics. While this might cause NASA to ponder whether it’s right for a Martian colony, would it stop a space corporation from offering an obscene amount of money to volunteers on a suicide mission to mine an asteroid loaded with rare minerals – money that might set their family up for life – even for generations?
Based on past experience, will we see a human-tardigrade hybrid?
To paraphrase a suitable adage: the water bear is already out of the bag.