They are correct. You’re not wrong, whales are indeed mammals. But “fish” isn’t a monophyletic grouping, meaning you either need to give up on using it as a category or you need to correct it by including everyone sharing the same LCA, meaning mammals would be part of your “fish” grouping.
Of course, that’s how it works within biological classification. Colloquially, you can call them anything.
I understand that and completely agree, but comparing taxonomical categories with common categorizations such as “fish” is also missing a big point. You can make better comparisons to get people to understand that taxonomy is made up and not reliable to follow religiously, barely even works as a guideline
They are correct. You’re not wrong, whales are indeed mammals. But “fish” isn’t a monophyletic grouping, meaning you either need to give up on using it as a category or you need to correct it by including everyone sharing the same LCA, meaning mammals would be part of your “fish” grouping.
Of course, that’s how it works within biological classification. Colloquially, you can call them anything.
Just gonna copy paste what I told the other guy:
I understand that and completely agree, but comparing taxonomical categories with common categorizations such as “fish” is also missing a big point. You can make better comparisons to get people to understand that taxonomy is made up and not reliable to follow religiously, barely even works as a guideline