Reminds me about this Memory Palace (a short podcast) about lobsters: http://thememorypalace.us/2010/08/episode-33-lost-lobsters/ http://thememorypalace.us/2010

Reminds me about this Memory Palace (a short podcast) about lobsters: http://thememorypalace.us/2010/08/episode-33-lost-lobsters/ http://thememorypalace.us/2010/08/episode-33-lost-lobsters/ – not very long ago they used to be gigantic compared to now. Evolution of the moment often favors animals that aren't as easy prey for humans. Somewhere else I read, I think a comment in AskScience about how insects used to be gigantic, an evolutionary biologist noted that over time species evolve to become larger. I would infer that given a set of ecological constraints, bigger is usually better for intraspecies competition (having already settled upon a successful niche for the species in general). But then things change, the species itself must compete anew as the ecology changes, and there can be resets, reverting back to smaller more efficient forms. Another thing alluded to in the article is that there's some complexity to simply maintaining larger forms. E.g., breathing air is more efficient if you have to bring in large amounts of oxygen. The crustacean line simply hasn't explored these areas. So even if there were always advantages to larger forms, not everything can just get bigger. But it always leaves the question, what about dinosaurs? So odd that the only true remnant seems to be birds that went down such a different path.