Great details in a very readable style. I like the idea that gravitation may have been weaker in the past. We as hybrid humans would then presumably have adapted over time as gravity strengthened, which might account for the big height variation in the skeletons that are known.
We would gradually become more 'normal' as skeletons as the population continually expanded. I heard @loowingbwoa talk about size reduction needed for oxygen also. Thanks for your work.
Looking forward to the next episode of Gulliver's Travels.