I recently finished reading Caliban’s War, the second in James S. A. Corey’s Expanse series of science fiction novels. Toward the end of the novel, two of the characters involved in a love affair sub-plot alluded to the possibility of marriage and children. James Holden was born and raised on Earth and Naomi Nagata was born and raised in the asteroid belt between Mars and Jupiter. Naomi’s physical attributes were that she was very tall and thin by Earth standards, and by virtue of living in a low gravity environment her entire life, her bone structure was not as strong as those that grow up on Earth. There is a short discussion in the novel about how women from the Asteroid Belt are not able to give birth in the same manner as Earth-bound women; they need some kind of assistance (the novel was not very specific).
NASA recently published preliminary results from its Twins Study. In that study, they compared the effects of one year in space on the International Space Station for one twin to his brother who remained on Earth. The International Space Station orbits the Earth inside the protection of the Van Allen Belt. The preliminary findings indicate that the twin in space not only had physical changes apparent to the naked eye – he was two inches taller – but also had undergone some changes in his DNA.
Being outside the Earth’s atmosphere changes us. Many of those changes may not be good for us. It may not just be morphological changes that need to be considered for humanity to travel and thrive beyond the Van Allen Belt. So how will humans deal with long term travel outside of the protection of the Van Allen Belt? Among the physical changes Humans would need to undergo a number of changes for space travel and planetary colonization; things like oxygen requirements, make up of muscle fibers, psychological tendencies, alternative means for nutrient absorption like photosynthesis or the ability to get essential minerals directly from rocks and dust rather than through food sources, the ability to see in low light, and physical size may all be necessary to improve the resiliency of humans in space. Then there is also the need to become more resistant to particle radiation from the sun and other sources.
With all these modifications, what will our space-exploring descendants look like? Maybe its like this: