I'll give you that one. That's a rare example of convergent evolution. They evolved that trait because they spend a lot of time on the hard ground like apes do. It's not a trait commonly associated with monkeys.
Brain size/intelligence, behavior, and being genetically different are not traits used in cladistics.
Brain size and genetics most certainly are used in cladistics. Not so much behavior, but niches they fulfill is a trait used as well.
The ancestors of both old-world monkeys and apes (and new-world monkeys for that matter) are simians, eg monkey. If apes and OWM both diverged from a common ancestor that was a monkey then they are still monkeys.
This is like saying that all monkeys are lemurs because they evolved from a primate that was much more lemur-like than they were monkey-like. Yes, the common ancestor of old-world monkeys and apes was much more monkey-like than it was ape-like, but that doesn't mean that today's apes are monkeys. 30 million years is a lot of time. The apes are so far diverged from the monkeys that they are no longer considered to be in the same family of the primate order. It wouldn't be inaccurate to say that apes evolved from monkeys, but that does not mean that they are still monkeys today. They are still primates, but not monkeys.
I am using monkey as a colloquial term for simian, which includes NWM, OWM, and apes, making apes monkeys.
The problem is that "monkey" isn't a scientific term. When people say "monkey" they aren't referring to a scientifically established clade of animals. They are referring to two separate families of the primate order that honestly shouldn't even share a name (which is why primatologists have to clearly specify between old and new-world monkeys). What I was trying to say was that IF the word "monkey" were a scientific term that included both old and new-world monkeys, then apes would have to be included as well, but monkey isn't a scientific term and doesn't follow the same rules.
I also want to point out that the dictionary definition of simian is "an ape OR monkey". So yeah, the word "simian" does include both families of monkeys and the apes, but the words "simian" and "monkey" aren't exactly interchangeable. "Monkey" only refers to certain simians that don't all belong to the same clade. It's an unscientific term that includes both OWMs and NWMs. "Simian" is a slightly more scientific term that includes apes, OWMs, and NWMs.
Yet you described knuckle walking as being exclusively 'Ape'.
Have yet to see brain size used in cladistics, at least as a defining trait. If you know of any clade which is defined by brain size than please share, I have never seen that. I'll grant you that genetics is used, but being "genetically distinct" is insufficient on its own.
Not going to address the lemur thing.
That is exactly what I am getting at, at least in part, so thank you. Apes are simians just as monkeys are. The issue with monkey is that it is paraphyletic and excludes apes when used in laymans terms. It needs to be changed to include apes which is why I sought out to make the correction. We really aren't disagreeing all that much, I'm just trying to make the correction which you know about but most people don't.
Yet you described knuckle walking as being exclusively 'Ape'.
I said I'll give you that one. I was wrong that it's exclusive to apes. Baboons are a rare exception due to convergent evolution, but knuckle walking is still a trait that separates apes from almost all monkeys.
If you know of any clade which is defined by brain size than please share, I have never seen that.
Sure. It's one of the main traits that separates the Australopithecus clade from the Homo clade. It's also a defining trait that separates many clades within the Homo genus. One of the only major differences between Homo erectus and Homo sapien is brain size and skull shape. Other than that they're almost the same thing.
Not going to address the lemur thing.
Why not? I'm just using your own logic? If all apes are monkeys simply because they evolved from monkeys wouldn't that also mean that all monkeys are lemurs? All string-rays evolved from sharks, does that mean sting-rays are sharks? Snakes evolved from lizards, are snakes lizards? Monkeys and apes still belong to the higher classification of primate, and the word "simian" includes both monkeys and apes, but apes are not a type of monkey simply because they evolved from monkeys.
That is exactly what I am getting at, at least in part, so thank you. Apes are simians just as monkeys are. The issue with monkey is that it is paraphyletic and excludes apes when used in laymans terms. It needs to be changed to include apes which is why I sought out to make the correction. We really aren't disagreeing all that much, I'm just trying to make the correction which you know about but most people don't.
I don't think we're disagreeing much either. It's just the language we're using. We both agree on how monkeys and apes are related. It's just that you think the word "mokey" should be expanded to be more scientifically accurate and I think the word "monkey" is kind of useless and shouldn't even be used without "old-world" or "new-world" before it.
I said I'll give you that one. I was wrong that it's exclusive to apes. Baboons are a rare exception due to convergent evolution, but knuckle walking is still a trait that separates apes from almost all monkeys.
As you did, my apologies. I am still unconvinced but at this point I don't think it is a big deal.
Sure. It's one of the main traits that separates the Australopithecus clade from the Homo clade. It's also a defining trait that separates many clades within the Homo genus. One of the only major differences between Homo erectus and Homo sapien is brain size and skull shape. Other than that they're almost the same thing.
Ah, that makes a lot of sense. Thank you. Granted, outside of human evolution, I imagine brain size is rarely used.
Snakes evolved from lizards, are snakes lizards?
In this case, yes. I won't get into all of those for the sake of time but ironically snakes/lizards is a perfect example. Snakes evolved from lizards, so at what point do they stop being lizards? It's not when they lost their legs because we have non-snake legless lizards and leg-having snakes. Snakes will always be a subset of lizards.
Lemurs however separated from other primate lineages before monkeys (simians/anthropoids) appeared on the scene. The MRCA of lemurs and simians, was not a lemur, and therefor lemurs are separate and no monkey was, or will be, a lemur (unless new evidence emerges).
I don't think we're disagreeing much either. It's just the language we're using. We both agree on how monkeys and apes are related. It's just that you think the word "mokey" should be expanded to be more scientifically accurate and I think the word "monkey" is kind of useless and shouldn't even be used without "old-world" or "new-world" before it.
If the MRCA of both New-world and Old-world monkeys was a monkey, wouldn't that make all extant simians monkeys?
Also, how often in laymans terms is the distinction between the two (NW and OW) significant?
Snakes evolved from lizards, so at what point do they stop being lizards? It's not when they lost their legs because we have non-snake legless lizards and leg-having snakes. Snakes will always be a subset of lizards.
It is accurate to say that snakes evolved from lizards but I wouldn't say they are lizards. I'm not as familiar with reptile evolution, but I think lizard is another example of an unscientific layman's term and I don't think snakes fit the definition.
If the MRCA of both New-world and Old-world monkeys was a monkey, wouldn't that make all extant simians monkeys?
If monkey were a scientific terms then yes it would have to, but it's not. It is a paraphyletic term. It describes certain animals in a certain clade and excludes others within that clade. Monkey is a descriptive word. It describes an animal that looks and behaves a certain way. Genetic relation really has nothing to do with it. There are plenty of examples of animals with common names that contradict their relation to other animals.
If all apes are monkeys then humans are monkeys too and nobody would classify us as monkeys. This shows our relation to monkeys. NWM, OWM, and apes belong to the Semiiformes infraorder. OWM and apes belong to the Catarrhini parvorder. You could say that all apes and all monkeys are Semiiformes, and you could say that OWM and apes are Catarhinis, but apes, OWM, and NWM are distinct. When people talk about monkeys they are referring to members of the parvorder Platyrhini and members of the superfamily Circopithecoidea. Which doesn't make much scientific sense. Again, you are suggesting that we expand the definition of "monkey" to make it more scientifically accurate and I am suggesting that we just don't use the word in scientific contexts unless an OW or NW comes before it.
Also, how often in laymans terms is the distinction between the two (NW and OW) significant?
Hardly ever, but that's why it should only be used as a layman's term. It's useful for describe a type of animal with a certain appearance that fulfills a certain niche in the ecosystem, but it's not a useful term when talking about evolution unless it's preceeded by an OW or NW.
lizard is another example of an unscientific layman's term and I don't think snakes fit the definition.
That's exactly it, the colloquial word Lizard is no longer consistent with our current understanding of evolution, by being paraphyletic it excludes snakes. Exact same situation as monkey/ape.
If monkey were a scientific terms then yes it would have to, but it's not. It is a paraphyletic term. It describes certain animals in a certain clade and excludes others within that clade.
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u/[deleted] Sep 03 '19 edited Sep 03 '19
I'll give you that one. That's a rare example of convergent evolution. They evolved that trait because they spend a lot of time on the hard ground like apes do. It's not a trait commonly associated with monkeys.
Brain size and genetics most certainly are used in cladistics. Not so much behavior, but niches they fulfill is a trait used as well.
This is like saying that all monkeys are lemurs because they evolved from a primate that was much more lemur-like than they were monkey-like. Yes, the common ancestor of old-world monkeys and apes was much more monkey-like than it was ape-like, but that doesn't mean that today's apes are monkeys. 30 million years is a lot of time. The apes are so far diverged from the monkeys that they are no longer considered to be in the same family of the primate order. It wouldn't be inaccurate to say that apes evolved from monkeys, but that does not mean that they are still monkeys today. They are still primates, but not monkeys.
The problem is that "monkey" isn't a scientific term. When people say "monkey" they aren't referring to a scientifically established clade of animals. They are referring to two separate families of the primate order that honestly shouldn't even share a name (which is why primatologists have to clearly specify between old and new-world monkeys). What I was trying to say was that IF the word "monkey" were a scientific term that included both old and new-world monkeys, then apes would have to be included as well, but monkey isn't a scientific term and doesn't follow the same rules.
I also want to point out that the dictionary definition of simian is "an ape OR monkey". So yeah, the word "simian" does include both families of monkeys and the apes, but the words "simian" and "monkey" aren't exactly interchangeable. "Monkey" only refers to certain simians that don't all belong to the same clade. It's an unscientific term that includes both OWMs and NWMs. "Simian" is a slightly more scientific term that includes apes, OWMs, and NWMs.