Claire Corlett

Fish Food, Fish Tanks, and More
You Are A Fish

You Are A Fish

Hi, welcome to MinuteEarth. I’m Jasper and you are a fish. Well… sort of. Of course, you don’t live in water. Nor do you have gills or fins. But there is certainly something fishy about
you… and it has less do with physical appearance, and more to do with evolutionary history and
how we classify species. So what makes a fish a fish? Well, traditionally, animals were grouped
together based on shared physical characteristics, but this traditional strategy of grouping
animals came long before we knew about evolution. Evolution revealed that all animals are related
by ancestry, and the more recently they share a common ancestor, the more closely related
they are. Sometimes animals that look very similar are
actually very distantly related. So today, scientists name groups of species
using “clades” which take evolutionary relatedness into account. A clade is a group that includes a single
most recent common ancestor and every one of that ancestor’s descendants. An easy way to identify a clade is to cut
one – and only one – branch off the tree of life. All of the species that fall off will form
a clade. And all species within that clade are more
closely related to each other than they are to any species outside the clade. For example, let’s look at the Great Ape
section of the Tree of Life. We could cut here and have a clade for Humans
and Chimpanzees. This shows us that we’re more closely related
to Chimpanzees than Gorillas because Gorillas are left out. But we could also go up a bit and make a cut
that includes Gorillas too. This is a larger clade and it shows us that
we’re more closely related to both Chimpanzees and Gorillas than Orangutans. So the whole evolutionary tree is actually
a Clade of Clades of Clades… all the way down to the tips. To figure out how we relate to fish, let’s
pick two animals we currently call fish – say, a goldfish and a shark – and first look at
how they’re related to each other. Now let’s use our Cladistic strategy and see
if we can cut out a “fish” clade. To include both of these species, we’d need
to cut the tree here, at the Gnathostomata branch. Now let’s add Humans to the tree and see
where we are. That’s right!… We’re actually in the same Clade as goldfish
and sharks because there’s no way to separate Humans from all fish without making more than
one cut. So if we wanted to group all the animals we
currently call “fish” together under a Cladistic naming scheme, humans – and in fact
all mammals – would also need to be part of that group. So is there something wrong with saying that
Goldfish and Sharks are both fish, but Humans aren’t? No, it just means that category isn’t a
clade and in some circumstances that may be more useful. But if you think about it, that traditional
association of the word “fish” with “ gilled, finned, water-dwelling animal” does blind
us to this interesting truth: although goldfish are related to sharks, they’re actually
more closely related to us. So maybe you should go around telling everyone
that you’re a fish. And when people give you confused looks, just
tell them you swim with the cladistic school of thought. You might have noticed some of the evolutionary
trees in this video were created by an app. Well, we actually built that app so you should
definitely check it out! You can use it to explore the Tree of Life
and build your own trees! Just visit and look for the
Tree of Life Explorer. You can also keep up to date with our latest
creations by subscribing to MinuteLabs on YouTube or supporting us on Patreon.

100 comments on “You Are A Fish

  1. After 5 years, MinuteLabs is back online and excited to share the Tree of Life Explorer, our app for exploring the evolutionary relationships between species! Check it out here:

  2. omg, im known as either penguin or fish at my school, but a year ago i always said i was a "blubfish" yes im weird, but "FISH". i was finally true for something. on accident– i think…

  3. me: you're a fish.
    friend: yes i am.
    me: so you are?
    friend: you are 2!
    me: how-
    friend: minute earth.

    thats how im here hi hello

  4. STUPID DUMB CRAZY🤣🤣🤣🤣🤣😠😠😠🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬

  5. Hmmm, I'm not sure I buy this. By that logic my great great great grandfather is more closely related to me than his uncle. – To me it seems like to logic only works from the bottom of the tree and upwards.

  6. 0:36 I've just realised how one of those fish looks like Magikarp.

    Is Magikarp based off a real fish or is this an Easter egg?

  7. But a species belonging to the same clade as another distant relative can evolve a lot, to a point that makes it far more different from that other species than one which exist in another clade. Can you say that humans share more of its DNA with a goldfish than a goldfish share with a shark? I'd like to know.

  8. Why The theory of evolution stoped.. or maybe it will continue.. some people will stay people and others will become something more developed or something else

  9. This does not really make sense because we are not fish how can we turn to fish to monkeys and to humans no sense we don’t have anything incommon

  10. I told my friend you are fish and then he just said one word ”wow” and then I told him more facts he just stay silent

  11. Makes sense. Gold fish and human have hard bones. Sharks have cartilage. Gold fish are closer to us than to shark.

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