4 ms·
The term "fish" is a case in point. Traditionally, the term means a creature which lives underwater, which would include whales and dolphins, and indeed used to
by nephihaha 2mo ago
The term "fish" is a case in point. Traditionally, the term means a creature which lives underwater, which would include whales and dolphins, and indeed used to, despite being mammals.
It gets worse. Whales and dolphins are more closely related to certain fish than those fish are related to some other fish. (As are we by the way.) There are also some fish, such as lungfish or certain eels which can spend more time out of water than whales and dolphins can. Some fish can even breathe air, which undermines another assumption about whales etc.
For some reason, I rarely hear fewer people objecting to jellyfish or shellfish being referred to as fish, even though these are more distantly related to fish than mammals are.
So biologically, the term "fish" doesn't make much sense.
- wpollock 2mo agoYour point is fishy. But if the IAU definition changes to "a body orbiting a star", we can rename them to "paparazzi".
- nephihaha 2mo agoThat was quite funny. I think my point is that terms are not always as precise as people think they are. As others have stated, there appears to be some kind of spectrum. Some of the inner planets have more in common with the moons of Jupiter and Saturn in some regards, than they do with Jupiter and Saturn themselves. For a start they have a surface that can be landed on. (Maybe not so much in the case of Venus or Io!!!) Pluto's most obvious problem is that it is too similar in size to a large number of other objects. But it does have some resemblances to planets and larger moons. I'm not keen on the phrase "dwarf planet" because it makes me think of objects that are much smaller than Pluto is.