4 ms·
I'm curious how many generations of natural selection it would take humans to adapt to the new gravity assuming we had no technology to do it.
by fracus 2y ago
I'm curious how many generations of natural selection it would take humans to adapt to the new gravity assuming we had no technology to do it.
- glenstein 2y agoA great question. And one fascinating but maybe disturbing thing we have seen from the ISS is the body seems to be pretty aggressive with bone decalcification in lower-G environments. I don't know if there's a corollary for higher-G, and the mechanism is orthogonal to questions about heritability, but meaningful changes happen even within the life span of a single person.
- msephton 2y agoGravity strength varies all over Earth so there are areas with slightly higher than normal gravity. eg. Dartmoor. I wonder if people who live there have higher bone density? https://en.wikipedia.org/wiki/Gravity_anomalies_of_Britain_and_Ireland https://en.wikipedia.org/wiki/Gravity_anomalies_of_Britain_a...
- rbanffy 2y agoI’d assume any such signal will be buried in the noise. The difference is very small.
- msephton 2y agoYou might be interested to know that the difference is quite noticeable! At least on Dartmoor. Walking feels very different.
- rbanffy 2y agoThe variation is about 0.7%. I doubt a human would notice anything different.
- msephton 1y agoYou can doubt it. If only it was possible to go to these locations in real life and verify it yourself? That's exactly what I did. I went to Dartmoor and the difference is quite noticeable. YMMV
- sitkack 2y agoAll life is a stack of autonomic systems. My hunch is that a human in a high G environment would make a bunch of adaptations even if they were born in orbit. By 3-5 generations they might even be another species. I am sure there has been some research done on raising mice in a high-g environment.
- sitkack 2y agoHypergravity and microgravity exhibited reversal effects on the bone and muscle mass in mice https://www.nature.com/articles/s41598-019-42829-z https://www.nature.com/articles/s41598-019-42829-z
- Qem 2y agoAssuming unchanged density of tissues, mass is proportional to volume and strength is proportional to muscle/bone cross section. According to the square-cube law[1], to keep the same weight to strength ratio under ≃20% higher gravity, body linear dimensions should be down-scaled by 1/1.2 ≃ 83%. So I think not many generations would be necessary, given individuals with 83% the average size or smaller are a common occurrence. The trait small body size should just become more common. [1] https://en.wikipedia.org/wiki/Square%E2%80%93cube_law https://en.wikipedia.org/wiki/Square%E2%80%93cube_law
- snapplebobapple 2y agoI look forward to the dwarf federation gaining independance from the terran hegemony. I only hoping we perfect stasis technology in time for me to sleep a few generations and witness it.