Once upon a time, pedants would scold people for calling apes monkeys. Now it turns out that apes actually are monkeys.*
*It used to be thought that apes were a distinct branch of the primate family tree from Old and New World Monkeys. Now it turns out that apes are more closely related to Old World Monkeys than either is to New World Monkeys, so it’s OK to call apes monkeys,
Bah! And trout are more closely related to people than either are to sharks, but trout are fish, and sharks are fish, but people aren’t fish. To hell with cladistics.
George Costanza: The sea was angry that day, my friends - like an old man trying to send back soup in a deli. I got about fifty feet out and suddenly the great beast appeared before me. I tell you he was ten stories high if he was a foot. As if sensing my presence, he let out a great bellow. I said, “Easy, big fella!” And then, as I watched him struggling, I realized that something was obstructing its breathing. From where I was standing, I could see directly into the eye of the great fish. [mine]
That’s fine by me. I mean, all it really does is illustrate how useless of a definition a “fish” is: “All aquatic vertebrates, with some exceptions” is as about as good as you can get.
I remember being taught that there are 2 kinds of whales - baleen and toothed, and that dolphins are a part of the toothed branch. I have never heard it phrased as “killer whales are dolphins” though.
In the book Behind the Dolphin’s Smile by Richard O’Barry he relates an incident where a captive dolphin mangled a woman’s arm… admittedly, it was an animal that had been mistreated and neglected for years and was pretty hostile towards everyone. Can’t give page numbers as I no longer own the book, but it does do a lot to tear down the notion that dolphins are these wonderful, friendly, inherently playful creatures. They’re wild animals.
I expect there have been attacks on humans, but they probably weren’t documented.
And if you don’t know who Richard O’Barry is – he’s the guy who did the animal training for the TV show Flipper, as well as several other projects.
Despite morphological similarities, extensive DNA studies have lead scientists to classify red pandas as a separate Family, not a subfamily within the raccoon family.
I believe this gets into the nature of folk etymologies that Trinopus mentions. Words like “monkey” and “fish” and “dinosaur” and even “planet” originated long before there was a systematic attempt at understanding classification and interrelatedness of the various types.
Everything that swims in the ocean is a fish. That means “starfish” and “jellyfish” are called those things because they’re “fish” in that sense. So whales are “fish” and so are sharks. And then someone comes along and says, “No, whales are mammals, they can’t be fish.” And then scientists get all busy trying to sort and shuffle and make the existing terms make sense, but they can’t really because the terms include things that don’t really fit.
Us laypeople get attached to words having certain meanings. Scientists muck around with those words to try to shoehorn them into a system that works from a science perspective, but it grates on the nerves and the sensibilities of the people who grew up thinking Pluto is a planet and sharks are fish.
The alternative can also be confusing. Looking at human ancestry, for example, and some people argue that “humans did not descend from monkeys, monkeys and humans descended from a common anscestor”, leaving out the detail of what that common ancestor was. Looking at the family tree, one of those ancestors appears to be Aegyptopithecus. Here is what wikipedia states:
Looking at that picture, I defy you to tell me why that is not a “monkey”. No, it is not any of the currently extant species of monkey, but it is still a monkey.
I also don’t think it’s fair to call humans “monkeys” or fair to call birds “dinosaurs”. It doesn’t make any more sense than calling humans “reptiles” because we descended from Synapsids, or calling us fish because way back in our ancestry there was a gilled swimmer. Humans have changed sufficiently that those terms are not accurate. Birds have changed sufficiently that “dinosaur” is not accurate. Sure, it’s neat to know that not all dinosaurs died out, that they kinda morphed into something else instead. But that’s not quite the same thing.
I’m sure I’m going to get heaped on for that last one.
While I agree with the conclusion that they are wild animals and are more than the stereotype we’ve been given by pop culture, I don’t think that one example is especially illuminating or representative. Take a prisoner of war who was daily beaten and tortured and starved and brainwashed for several years and then newly free him, he’s not going to necessarily be very friendly to be around. Doesn’t mean humans by nature are as testy and untrusting as that guy.
It’s possible. There’s a comedy bit about how dolphins have this reputation for saving distressed swimmers and whatnot, but it’s an act. We don’t hear about the cases when nobody else is around, and the dolphins decide to eat the person. But if there’s other people around, they play nice and blame the sharks.
I’m not as adamant as MIchelleRose, but I find it intriguing that there are so few known incidents of even Killer Whale attacks on humans. You’d think surfers, who are reasonably frequently attacked by sharks, might have more cases of mistaken identity to report. So far, we’ve got 1 surfer bitten in 1974. Worldwide.
If you don’t go out of your way to be a dick, wild dolphins seem reasonably friendly towards humans - curious enough to check us out when they find us swimming around, not typically attacking or acting aggressive.
I admit, I like cladistics as a taxonomic strategy, because it can be closer to absolute and objective. You can’t put Zebras in a different group than horses, because there are things we call “horses” branching off both before and after Zebras. Cladistics fans are really pissy about that. But even this isn’t totally absolute, and it also messes up some of the comfortable old classifications.
There are also (I’ve read somewhere) contradictions between fossil cladistics and DNA clock cladistics, so, clearly, we need to have more work done in calibrating.
I don’t think many people say that. The last common ancestor between monkeys and humans was almost certainly a monkey, and would be classified as an (extinct) species of monkey by scientists. What you DO hear people say is something like: If humans evolved from monkeys, how come there are still monkeys around today? Which betrays a lack of understanding of how evolution works.
Cartilaginous "fishes’ arent really very closely related to “bony” fishes (Osteichthyes). So no.
However, due to the same environment and many times the same niche, the two look a great deal alike in many cases. So yes.
But even way back in the Systema Naturae old Linnaeus had “Pisces” being the Bony fish, and the sharks etc were sent off to that garbage can lumping of Amphibia, with the frogs, lizards, snakes and lampreys.
So, the answer is either “yes or no”: they are both a *paraphyletic group of organisms *, so “yes”… But that’s not very useful. Scientifically, they have pretty much gotten rid of the term “fish” for taxonomy. So then “no”.
I’ve have people say that on this board. Trying to correct me when I said humans descended from monkeys. “No, they descended from the last common anscestor between humans and monkeys.”
Look at the family tree under Classification. It shows how apes are excluded from “monkeys”, but “monkey” covers the two sub groups under Simiiformes (simians).
Looking back at Aegyptopithecus, it is classified under “Haplorhini”, which is one step back from Semiiformes, and includes Tarsiiformes (Tarsiers), which are not monkeys. However, given that humans (and all apes) descended under Semiiformes, and Simians are monkeys, I would say we descended from monkeys - just not any of the extant monkey species.
Similarly, there is confusion over the term “ape”. It appears some people use it as a synonym for gorillas, and humans are not descended from gorillas. However, we are apes - the common ancestor of gorillas and humans was an ape.
Unless “ape” is paraphyletic, and means “all Hominoidea except for Homo sapiens” or some such. Different biologists have used it differently.
To try to rephrase what DrDeth said…
The things we most readily identify as “fish” are the bony, finned fish like trout and golfish and swordfish and bass and catfish, etc. They have a bony skeleton, bony fins, gills. Amphibians and reptiles and mammals and birds are all descended from bony finned fish.
Sharks are not bony - they are all cartilage. They are closely related to rays and skates, also cartilaginous. Their ancestry diverges from bony fish earlier in the timeline before bony fish.
Humans, being descended from bony fish, are more closely related to fish than sharks are. But sharks look like bony fish, with a similar body plan of bilateral symmetry, streamlined body, gills, fins, tail.
Whales also look like fish, with similar features, sans gills. Scientists decided that since whales are mammals, they can’t be fish, except of course all mammals are descended from fish, but then calling them fish would confuse things.
Laypeople still call things like crayfish and starfish and jellyfish “fish”, but they aren’t bony fish, they are different phylums than bony fish.
Quick definitions to make the below more easily understood:
A monophyletic clade (group of organisims) is labeled such because that clade contains all the descendants of one common ancestor. “Mammals” are monophyletic.
A paraphyletic clade is a group where one or more descendant lines from that common ancestor are excluded from the group. Reptiles are paraphyletic, because they include all descendants from a common ancestor except for mammals and birds.
This sort of thinking is true if one ascribes to a gradistic form of classification, but not for a cladistic one; or, to put it another way, if you group things based on how they look rather than their evolutionary history.
Also, humans aren’t described as “reptiles” under a cladistic scheme, because nowadays Reptilia is effectively synonymous with Sauropsida; humans are members of Synapsida, which is the sister clade of Sauropsida within Amniota.
Under a cladistic scheme, to deny that birds are dinosaurs or humans are monkeys is an arbitrary (and false) denial. Would you deny that humans are mammals? Would you deny that humans are primates? Would you deny that humans are haplorrhin primates? If the answer is to any of those questions is no, then why would you deny that they are therefore also monkeys? Similarly, birds are ornithuran maniraptoran coelurosaurian theropod dinosaurs, so there’s no non-arbitrary reason to deny them their dinosaur-hood.
Also, to clarify this:
Sharks (Chondrichthyes) evolved from acanthodians, which had bones. Acanthodians also evolved into Osteichthyes, which are what are collectively and colloquially known as “bony fish”; that group is further subdivided into Actinopterygians (ray-finned fish, which includes most of the ‘traditional’ fish, such as carp, tuna, trout, marlin, guppies, etc.) and Sarcopterygians (“fleshy-finned” or “lobe-finned” fish), which includes coelocanths, and all tetrapods (including dolphins, killer whales, monkeys (including humans), and reptiles (including dinosaurs (including birds)), etc.).
I’m so confused. Are we actually debating whether killer whales are dolphins? I thought that was pretty much settled. Are we also going to debate whether they’re mammals?
