0:01 So this is going to start out kind of
0:03 philosophical with the fact that words
0:05 have meanings all of them and those
0:07 meanings mean something in our heads and
0:09 this is fine. That is where meaning
0:11 begins. But it is not where meaning
0:14 always ends. Now the crazy thing is that
0:16 as we pass words around they mostly mean
0:19 the same thing in your head as they do
0:20 in my head. If that's not the case then
0:22 conversation becomes weird and hard. And
0:24 I see this happen all the time,
0:25 especially on the internet where
0:26 different groups of people have
0:27 different. It doesn't matter. The way
0:29 that we actually imagine and use words,
0:32 what the definition of a word is is the
0:34 thing that it means when you think of
0:35 it. And that's a fine kind of
0:36 definition. When it comes to that kind
0:38 of definition, there is obviously a
0:41 thing that fish are. This is a fish. And
0:44 this is a fish. This is definitely a
0:46 fish. Why is a bass to me like the most
0:48 fishlike fish? I don't know. But is this
0:51 a fish? I mean, yeah. It's not really
0:53 fish shaped. What about this? That's a
0:55 horse, but is also a fish. So, as
0:58 always, things are a bit of a mess on my
1:00 we never left the water shirt here.
1:01 There's There's like weird fish here.
1:03 There's a orfish. That's like a long
1:06 fish. There's a whale shark. What's that
1:09 even? Mao. What? What? But
1:11 interestingly, this used to be a fish.
1:13 And this also used to be a fish. This as
1:15 well. This is a silverfish. And
1:17 interestingly, it was never a fish. It
1:18 just reminded people of fish. We've had
1:20 words related to fish for a very long
1:23 time. And mostly what they meant was the
1:25 thing that you think of as a fish. Not
1:27 anymore though. And how we ended up
1:30 there is very interesting. Now the thing
1:33 that means fish is kind of not what you
1:35 think of as a fish. Or it is. It still
1:37 is. But there also it isn't. There's a
1:40 fight going on. And I'm in it. I'm in
1:41 the fight. And I want to be in the
1:42 fight. I like it here. But how we ended
1:44 up in that situation is very
1:45 interesting. And also it leads me to
1:48 believe that maybe sharks aren't fish or
1:51 whales are. What people think of as a
1:53 fish has changed over time as our
1:55 language has gotten more specific. Used
1:57 to be anything moving around in the
1:58 water was a fish. Starfish, jellyfish,
2:01 cuttlefish, whales, seals, and penguins
2:02 were not considered fish because they
2:04 spent a lot of time on land. And people
2:06 messed around with this. Like Aristotle
2:08 was like a bunch of these things are
2:10 pretty different. As early as that era,
2:12 we started separating out things that
2:14 didn't have internal structures. So
2:16 sharks and bass and whales, fish, but
2:19 squid and octopuses and and snails and
2:21 jellyfish and starfish, different things
2:23 that got different words. He had a whole
2:25 system for dividing things up. Did they
2:27 have blood? Did they have bones? Etc.
2:29 But that was very different from what
2:32 people thought of as fish. And people
2:33 kept thinking of squids as fish, even
2:35 though Aristotle was like, "No, no, no.
2:36 They're a different thing." When I was
2:38 in school, people were still a little
2:40 unclear on whether whales were fish.
2:42 That was the '9s. In the Middle Ages,
2:45 for weird logistical reasons, fish
2:47 started to be redefined for a lot of
2:50 people because you could eat fish during
2:52 meat fasts, like during Lent. And some
2:54 people didn't have access to like not
2:57 just fish, but like any food that wasn't
2:58 meat. And so they started looking at
3:00 different animals and being like, maybe
3:02 that's a fish. I don't know. Ended up
3:04 beavers definitely considered fish and
3:06 could be eaten during Lent. Same thing
3:08 goes for barnacle geese, which people of
3:11 the time thought grew on driftwood, like
3:13 popped out of barnacles. You could see
3:15 how maybe that would be a fish. Also,
3:16 puffins lived a lot of their lives in
3:18 water, so they were considered fish.
3:19 Now, the jury is out on whether people
3:21 actually thought these things were fish,
3:23 but it really does feel like they did.
3:25 Like they looked at beavers and they
3:26 were like, "Their tails are scaly. They
3:28 live in the water. I don't know. Kind of
3:30 fishy." Now, if you look up the
3:32 definition of fish in the dictionary and
3:33 the words there were just like that
3:36 thing you think of as a fish, that would
3:37 be a bad definition. That would not be
3:39 satisfying. It's almost weird that there
3:41 has to be a definition of fish. Like, I
3:43 don't know the history of dictionaries,
3:44 but there must have been a time when
3:45 they were like, I guess we got to
3:48 include all the words, even fish, which
3:50 everyone knows what a fish is. Like, I
3:52 don't have to define fish to people.
3:55 Children around fish, no fish. But like,
3:56 I guess we got to do it. But before
3:58 dictionaries, like the thing you think
4:00 of when I say fish is mostly what we
4:02 were going with. That was most of human
4:04 history. And what definitions today
4:07 mostly do with fish is that they try to
4:09 describe what you think of when you
4:11 think of a fish. Cambridge dictionary.
4:13 An animal that lives in water is covered
4:16 with scales and breathes by taking water
4:18 through its mouth or the flesh of these
4:20 animals eaten as food. I mean, no, like
4:23 catfish don't have scales. Mudskipppers
4:25 are evolved to not live entirely in the
4:27 water. But whatever. Google a limbless,
4:28 cold-blooded vertebrate animal with
4:31 gills and fins and living wholly in
4:33 water. Again, muds skippers, but also
4:35 tuna. Maybe not coldblooded. It turns
4:38 out also lots of fish don't have fins.
4:40 So, this is a bad one. Miriam Webster is
4:43 improving any of numerous cold-blooded
4:45 strictly aquatic cranate vertebrates
4:48 that include the bony fishes and usually
4:50 the cartilagynous and jawless fishes.
4:52 So, those are actually the that's a
4:53 little bit of foreshadowing for you. and
4:56 that have typically typically also you
4:57 should have put typically on
5:00 cold-blooded Miriam Wikipedia. A fish is
5:02 an aquatic amniotic gilbearing
5:05 vertebrate animal with swimming fins and
5:07 a hard skull but lacking limbs with
5:09 digits. This is the best one, but it
5:11 still isn't quite there. There are some
5:13 fish that don't have fins. What all of
5:16 these things are is an attempt to create
5:20 a line that you can draw around all fish
5:22 that excludes all things that aren't
5:24 fish. Some of them do better jobs than
5:26 others. But wildly this is a very
5:28 difficult thing to do. There are a lot
5:30 of fish. The world is large. There's a
5:32 great diversity of life. But you can see
5:34 how these definitions are just an
5:37 extension of what do I think of as a
5:39 fish. Create a list of attributes that
5:41 draws a line perfectly including all
5:42 things that I think are fish and no
5:44 things that I don't think are fish. And
5:47 this is fine. Definitions are for humans
5:49 to use. And absolutely, even though a
5:51 manta ray isn't really very fishshaped
5:54 and hagfish don't have fins and catfish
5:56 don't have scales, I feel like they
5:58 should all be included. But you get the
6:01 idea. A fish is like a thing that you
6:02 think of when you think of a fish. And
6:05 that is often what definitions do. But
6:08 there is another thing definitions can
6:10 do. If I ask you to define a car, you
6:12 will have to give me a list of
6:13 attributes. I just don't actually see
6:16 another way. He got tires, an engine,
6:18 carrying a smallalish number of people,
6:20 doesn't have a flatbed, and that's
6:22 imperfect, but we're kind of stuck with
6:27 that. This is not the case with life. In
6:29 the late 1800s, after people realized
6:32 that animals evolved from one another,
6:34 it started to be pretty clear that there
6:36 was actually a reason why fish tended to
6:38 have all of these common properties.
6:40 Upright tail fins, amniotic,
6:42 two-chambered hearts, pumping blood,
6:44 gills, and hard skulls. And instead of a
6:48 list, we could have a definition that
6:50 told us something new because it brought
6:53 the definition outside of our minds,
6:56 outside of the vibes, outside of what we
6:59 think of as a fish and into the real
7:02 world, not in here, out there. This
7:04 conversation, which has now been going
7:06 on for decades, is like a thing that's
7:08 happening and you're in the middle of
7:11 it. When we moved from defining fish as
7:13 the thing that feels like a fish to me
7:16 to instead a list of things that include
7:17 all of the things I think of as a fish
7:19 and none of the things that I don't.
7:20 That wasn't actually that much of a
7:22 leap. That definition was still inside
7:25 of us. A much better definition, but one
7:27 that no one currently uses and is part
7:30 of this fun, I think fun discourse. No
7:32 one's actually mad here, but a much
7:33 better definition is when it actually
7:35 describes something that exists in the
7:38 real world. And the lineage of fish,
7:40 starting with the first common ancestor,
7:42 a vertebrate with fins and scales and
7:44 blood and a two-chambered heart and a
7:48 hard head, is a real thing that existed
7:50 in the real world. And that is the
7:53 common ancestor of all fish. But
7:55 interestingly, no current definitions of
7:58 fish discuss lineage because they
8:00 cannot. And I will now explain that
8:02 there was one common ancestor that gave
8:04 rise to all of the fish. sharks and
8:06 manta rays and bass and marlin. But that
8:07 common ancestor also gave rise to
8:10 beavers and birds and the prop comedian
8:11 Carrot Top. And this would actually be
8:13 fine. Birds have a single common
8:15 ancestor. They are a group that just
8:17 includes birds. Dinosaurs have a single
8:18 common ancestor. They are a group that
8:20 just includes dinosaurs. And tetropods,
8:23 the land vertebrates, all have a single
8:24 common ancestor. They are a group that
8:26 just includes tetropods. The fish group
8:28 includes three different groups. The
8:30 bony fish like bass and marlin, the
8:32 cartilagynous fish like sharks and rays,
8:34 and the jawless fish like hagfish and
8:36 lamp rays. But cartilagynous fish and
8:39 bony fish split off from each other 420
8:41 million years ago, while tetropods and
8:43 bony fish split from each other 380
8:45 million years ago. 40 million years is a
8:48 long time in evolution, and we are way
8:52 more closely related to bass than bass
8:54 are to sharks. So here's the problem. We
8:55 are comfortable with the line that we
8:58 drew around fish. Unfortunately, that
9:00 line is drawn in such a way that it
9:02 cannot line up with the definition of
9:04 fish that is created when we remove
9:06 ourselves from the equation and seek a
9:08 definition that is about more than just
9:10 vibes. And so, if we want a definition
9:13 of fish that is about reality rather
9:15 than vibes, and I understand that we may
9:16 not want that, sometimes you just want
9:18 to say fish are the things that are like
9:20 fish. But in that case, you do have to
9:22 accept that whales only got brought out
9:24 of that definition through careful
9:26 science. But that's fine. But if we want
9:28 a definition of fish that is about
9:30 reality rather than vibes, that pulls
9:32 the definition outside of us and into
9:34 the actual biological reality of life on
9:36 Earth, you can absolutely do that. We
9:38 could create a group that includes all
9:40 of the fish, including the tetropods.
9:42 The problem is we already have a name
9:44 for that group. It's the cranates. Any
9:47 animal that has a skull is a fish or
9:50 descended from a fish. There are no fish
9:51 that are not descended from the first
9:53 cranate ancestor all those hundreds of
9:54 millions of years ago. But I actually
9:56 don't like that as a classification cuz
9:58 it's just too broad and we already have
10:00 that. We've got craniates. But also
10:02 hagfish that are cranates but not
10:04 vertebrates are so different from all
10:07 the other fish that I will happily call
10:09 them not fish. Like the hagfish, maybe
10:11 they're like cuttlefish and jellyfish,
10:13 just something named fish but not
10:15 actually a fish. No one is making them
10:18 be fish. They don't have to be fish.
10:20 However, this doesn't actually solve our
10:23 problems. If we cut the hagfish off and
10:25 say, "Okay, fish is everything descended
10:27 from the ancestor of all the other fish,
10:30 we also have a name for that. That is a
10:32 group that already exists as well.
10:34 That's the vertebrates." And so, if we
10:36 want fish to actually be a thing, we
10:38 have to go one step further. Perhaps the
10:41 cartilagynous fish aren't fish either.
10:44 Perhaps sharks and rays are just sharks
10:46 and rays. And if we carve them off too,
10:48 we would actually be left with a group
10:52 that are fish and are not represented by
10:54 anything else. This is the bony fish.
10:55 The group that includes all of the fish
10:57 descended from the first bony fish,
10:58 which has pretty much everything you
10:59 think of as a fish in it except for the
11:00 sharks and rays and hagfish and
11:03 lamprays, but also does include the
11:05 tetropods. So, this doesn't solve the
11:07 second problem, which is that tetropods
11:09 would still be in the group. But here's
11:11 the thing. I don't think this is a
11:12 problem because I think I'm a fish. In
11:15 order to make fish a useful category
11:17 that we don't already have a very large
11:19 encompassing name for, we have to narrow
11:21 it down. But it's literally impossible
11:23 to narrow it down so far that it doesn't
11:25 include humans without arbitrarily
11:27 drawing a line at the shore. And this
11:30 division in which only bony fish are
11:33 true fish makes sense to me because it
11:35 highlights how extremely different
11:37 sharks and rays are from bony fish,
11:39 which we don't think about. Like we
11:41 can't hold it in our brains, but it's
11:42 really true. And that's to say nothing
11:45 of the hagfish which are I mean just
11:47 look at them like that's that's a fish.
11:50 The most likely outcome however because
11:52 fish aren't that important to us like we
11:54 don't spend that much time around them
11:55 the way that we do like like we see a
11:57 reptile and we see a bird and because
11:59 we're land animals we see those things
12:00 as very different from each other even
12:01 though they are much more closely
12:03 related than a shark is to a bass but
12:05 because we are what we are we just
12:07 continue to operate on fire. This is
12:08 what's going to happen. It just means
12:11 that I get to keep telling you that
12:13 while the things you think of as fish
12:16 definitely exist, there is no actual
12:18 thing in the real world outside of our
12:21 minds that the word fish describes.
12:23 There is no such thing as a fish. Thank
12:25 you to everybody in the comments of my
12:28 video about fish who encouraged me to
12:29 make this video about why whales are
12:31 fish or maybe they aren't and sharks
12:33 aren't fish. I don't know. My point is,
12:34 thank you. I had a good time making
12:37 this, especially because of the the
12:40 point here that definitions can be two
12:42 things. They can be our mind's version
12:43 of what something is, but they can also
12:46 be like the real outside of our mind
12:48 version of what something is. And I
12:50 think that that's fascinating. And also,
12:51 I really want to have that conversation
12:53 about life because I hate the current
12:55 definitions of life that are it's just a
12:58 line drawn around something rather than
13:00 actually trying to name what it is. But
13:02 regardless, the We never left the water
13:04 shirt designed by Matias Ball is still
13:06 available, but only for the next week.
13:08 After that, we will take the exact
13:10 number ordered and print that exact
13:12 number of them and ship them out so that
13:13 we don't accidentally make too many or
13:16 too few. So, if you, an organism that
13:19 brought water out of the water and onto
13:21 the land and kept it inside of your body
13:23 with gratinous skin, want this shirt,
13:24 you can get it, but only for another
13:26 week. All right, that's the end of the video.
