People like Elon Musk and others in the “space settlement” camp believe that NASA and the US space industry should colonize Mars and make homo sapiens a multi-planet species. Musk wants SpaceX to send colonists to Mars one day, while NASA talks about building sustainable habitats on the red planet. Even if we overcome the technical and financial challenges that stand in the way of humans on Mars, we know very little about how microgravity and increased radiation will affect humans’ ability to reproduce in space. Without reproduction there is no permanent colony and early tests are not promising.
But let’s assume that SpaceX, or an international coalition led by NASA, or the Chinese space agency eventually figure out the engineering and financing of a Mars colony. Let us also assume that the biology of reproduction in space and on alien worlds is a solvable problem. After Homo sapiens became a multi-planet species, the question arises: Would we remain a single species of humanity? Scott Solomon thinks a lot about this question in his new book future people, which will be published in October by Yale Press. In it, he explores the future evolution of our species, including some musings on Mars.
“The overall concept for the book is to ask about our continued evolution, from the perspective of a scientist taking what we know about our past, what we know about today, and thinking about the long-term possibilities for our species,” Solomon, said a biologist at Rice University in Houston. What, he wondered, would it take to lead to the development of a new species? In other words, how long would humans on Mars remain human?
Solomon explained that new species usually develop when a barrier prevents a population from mating, such as on an island archipelago, so species on separate Galapagos islands evolve along different lines. With modern humanity, of course, the trend goes in the opposite direction, as humans move around the planet at a rate unprecedented in human history. “So on planet Earth it would take a big change to imagine that we’ve isolated populations long enough to have different species,” he said.
The gap between Earth and Mars could be such a barrier, if the Martian colony were self-sufficient and persistent. Natural selection allows humans and whatever organisms they bring with them, such as plants, to evolve and adapt to Mars’ harsh environment and low gravity, which is only a third of Earth’s gravity.
Lacking a magnetosphere, Mars is bombarded by an increased radiation velocity, which also promotes speciation. Ionizing radiation causes mutation in genes, which would be a source of new genetic variations. That could speed up the adjustment process. On the other hand, Solomon said, the higher radiation could kill people. Or it could lead to settlers constantly settling into tiny habitats and spacesuits, leading a Morlock-like existence and meeting a similar evolutionary fate.
Ultimately, it may take a long time before speciation occurs. The only solid data point we have on Earth is the colonization of the Americas, which was populated around the end of the last Ice Age by waves of humans moving across the Bering Strait. These populations were then isolated from the rest of the world for about 10,000 years. When Europeans arrived, they found a separate population of Native Americans, Solomon said, but certainly no other species. That would suggest that on a planet with a similar atmosphere and gravity to Earth, it would take more than 10,000 years for a human population to form. Mars, of course, is not that planet.
Another factor to consider when humans consider colonizing other worlds, Solomon said, is the “founder effect,” which simply means that when a small number of humans establish a new population from a larger population, the founder genes make a huge difference. will have influence. ahead of the population. This happened to the small groups of people who spread out from Africa.
“I think about what the long-term fate of our species may be,” Solomon said. “In selecting settlers, I don’t believe we should try to select what traits we want in a new kind of people. But it’s interesting to think that if you just took people from certain populations, or tried to include a diversity of all of humanity, how those outcomes would be very different for the potential of what could become a new kind of people .