I was watching a video from Jack Spirko where he said that tomatoes stay up on their own in the wild. How exactly do they stay up then?
The size of the tomato has been increased with human selection. Wild tomatoes are berry sized, so the plant doesn't need extra support. The same is true for most plants that humans have selectively bred, although for tomatoes, the plant is not fibrous or tough enough to bear much weight. Genetic engineering has come a long way, but it will be a while before jellyfish have (good) bones.