| ▲ | ralfd 6 days ago |
| At least you could exclude jawless, cartilaginous, and lobe-finned fish. That would leave you with 99% of what people call fish. But as said it would exclude sharks, they would need to be their own group. More bothering me is that there are no trees. There are just many plants which have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. |
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| ▲ | pavel_lishin 6 days ago | parent | next [-] |
| Yeah. Terms like "fish" and "tree" are more like "quadruped" than they are like "rodent". |
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| ▲ | ndsipa_pomu 6 days ago | parent | next [-] | | Except that you can come up with a decent definition of "fish" and "quadruped", whereas there's no definition of "tree" that covers all the cases. https://www.theatlantic.com/science/archive/2018/04/how-do-y... | |
| ▲ | IAmBroom 6 days ago | parent | prev [-] | | Except that "quadruped" is (AFAIK) phylogenetic: Tetrapoda. | | |
| ▲ | pavel_lishin 6 days ago | parent [-] | | > * tetrapod (/ˈtɛtrəˌpɒd/;[4] from Ancient Greek τετρα- (tetra-) 'four' and πούς (poús) 'foot') is any four-limbed vertebrate animal of the clade Tetrapoda (/tɛˈtræpədə/).* Huh. I always thought it was a more generic term for any four-limbed animal. TIL, I guess! | | |
| ▲ | IAmBroom 6 days ago | parent [-] | | Honestly, I can't think of a non-tetrapod animal that is four-limbed. I mean, unless you cut one leg off a starfish. |
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| ▲ | Dylan16807 6 days ago | parent | prev [-] |
| It's much more valid for trees. They've evolved many times and there is no common ancestor that is itself a tree. Fish evolved once, and then a specific subgroup is excluded. That's fine. |
