In this context, my world assumes an infinite universe so parallel Earths are possible and probability isn't an issue. My planet has half the gravity of Earth but an atmosphere 12x denser, although, answers do not have to be restricted to this planet specifically and can be general in nature.
I've read that Insects, for example, walk very differently to larger creatures as gravity doesn't affect them in the same way - See this article. So on a planet with less surface gravity, how would it affect the ways things walk, look and evolve? Presumably, the weight of a creature would scale proportionally to the change in gravity. In this case, things could grow 1.26x larger at $0.5g$. A T-rex parallel, for instance, could be 15.5m long instead of 12.3m. And the weight limit of flight would be doubled (not accounting for Air Density).
I've outlined a few things I feel might be effected:
- Would bipedals have more of a spring in their step so-to-speak?
- Would animals in general evolve to move slower as each step would propel them forward with more force?
- How would falling be affected with a lower terminal velocity? Would falling no longer be an issue?
- If land-animals first evolved with 6 limbs, would the increase in stability make them more likely to retain the extra limbs through the evolutionary process?
- Or would the reduced weight of these creatures counter-act the change in gravity? So a human with half the mass in $0.5g$ would look the same as a regular human on earth whilst walking (if you were watching a video per-se).
I'm thinking more about how it translates into a visual medium so I am specifically interested in how the motions of movement would be different. Bonus points if you can work Air Density into your answer.