Consideringlily said:
This seems as though it is a critique of style over substance. My understanding is there are 3 possible ways to group canids. He explained 3 but the third group with the extinct dog like species he didn't number.
Cirbryn said:
Extinct dog-like species would fall into his second grouping ("any of the wild canids who did not descend from Asiatic wolves"). My new theory, after reviewing Aron's response farther down, is that he was thinking 1) domestic dogs; 2) any member of the "dog family" (Canidae); or 3) any member of the dog family excluding wolves (and possibly foxes). These are two monophyletic meanings (1 and 2) and one polyphyletic meaning (3). Aron said he was thinking of two paraphyletic meanings and one monophyletic, so I could still be wrong.
Domestic dogs that arent related to wild dogs illustrates a paraphyletic group. Canidae excluding wolves is also a paraphyletic group. The monophyletic definition would have to consider wolves to be dogs. Similarly, the only possible monophyletic use of monkeys would have to include basal anthropoids currently considered to be ancestral to both New World monkeys and Old World monkeys, and fully-simian descendants of prosimian half-monkeys, which for some strange reason aren't called monkeys just like wolves aren't called dogs.
consideringlily said:
Here is a clarification point. Monkey and dog are roughly equivalent generas of animals within the families of Primates and Canids
http://en.wikipedia.org/wiki/Canidae
http://en.wikipedia.org/wiki/Haplorrhini
Cirbryn said:
Well, "true dogs" (as the term is used by your first cite) would be a genus (Canis) in the Canid Family, but Aron's second definition of "dog" includes things in the dog family outside of the Canis genus (such as the list he gives in post 120 of African wild dogs (Lycaon pictus), dholes (Cuon alpinus), raccoon dogs (Nictereutes procyonoides) and bush dogs (Speothos venaticus)). Actually, sorry, it's just occurred to me that you probably meant "taxa" (plural of taxon - any taxonomic grouping) instead of "genera" (plural of genus). Anyway, the difference between "dog", used in that sense, and "monkey", is that "dog" refers to a single monophyletic family,
That would be the family, Canidae, which includes all the above, as well as
Hesperocyon coloradensis, Canus lupus, and many more.
whereas "monkey" refers to several different families that together form a group that is either paraphyletic (assuming apes evolved from something we'd call monkeys),
And assuming that apes aren't monkeys themselves. Otherwise, they would be monophyletic in this case.
or polyphyletic (assuming old-world monkeys and new-world monkeys evolved separately from something we might call lemuroids). Haplorrini is a monophyletic suborder, but it includes apes and tarsiers as well as monkeys. I could sum up this entire discussion by saying that Aron wants various colloquial terms like "monkey" and "fish" to be monophyletic, and they aren't.
They can be, and should always have been. For some weird reason which no one dares explain, scientists consider prosimians to be "
half-monkeys," as in not fully monkeys 'yet (in the evolutionary sense). Yet their 'fully-simian' descendants have always been considered monkeys by the general public and common definition, while some scientists inexplicably refuse to call them by that name. Somehow, they can declare the ancestor of Old World monkeys to be very like specific species of New World monkeys, but even if it is a basal Catarrhine living after the divergence of Platyrrhines, it still seems verbotten to declare that to be a monkey itself even though that is what it must certainly be, and that's what everyone but a primatologist would call it. The only way they would admit that the common ancestor of all monkeys was a monkey itself, is if it was all Greek to us.
Eosimias, the "Dawn monkey"
potential mother of all monkeys, including apes, including humans.
We know that "simian" means "monkey" in both Latin and Greek, and both apes and monkeys (even the basal ones) are collectively classified as 'simians', or 'Simiiforms' -which can be used in place of "anthropoid" whenever the mood suits. So why won't they admit in English that they're all monkeys? That they're all the same, both cladistically and colloquially?
"Anthropologists and primatologists have been among the last researchers to adopt phylogenetic methodology and taxonomy. As such, a number of important primate clade names remain paraphyletic."
--
First Phylogenetic Nomenclature Meeting, Paris, Muséum National dHistoire Naturelle, July 6-9, 2004, Académie des Sciences de Paris.
If the word monkey can continue to mean anything in the modern scheme of classification, it can only the colloquial equivilent of Anthropoid.
Actually that's a good question: How would you sum up the discussion so far Aron?
Ill answer that after you submit your reply to post # 136.
consideringlily said:
If you restrict a discussion of dogs to one species of dog (canis lupus) when in fact there are more than one genera, that are not directly descended from the gray wolf, it seems myopic. Especially when you are asking what a dog is.
Cirbryn said:
Agreed. But the context wasn't a discussion about dogs. It was about what constitutes a species, and whether a new species should still be considered "part of" the species from which it evolved. I said it shouldn't since species are defined as being genetically isolated from each other. To which Aron responded "But a new species of dog is still a dog". (See posts 89, 96 and 97). See the problem?
Not really, no. Even in the Linnaean perspective, the new species would still belong to the family, Canidae, and the genus, Canus as well. Would it not?
consideringlily said:
But if you'll notice the human genus homo is still nested within the haplorrhini suborder within the primate family. Just as the genus of canis is still within the canidae family.
Cirbryn said:
Rght, and no one denies that monkeys and apes (including humans) are both haplorrhini. But you'll notice (at the bottom of your haplorrhini cite) that the family Hominidae (including humans) is not nested in the family Cercopithecidae (old-world monkeys). Aron has been doing a lot of arguing to the effect that they ought to be so nested, but the fact remains that they aren't.
Wrong. Ive been arguing that both Cercopithecoidea and Hominoidea are both together nested within Propliopithecoidea, a basal group of Catarrhines which are also commonly recognized as Old World monkeys in the literal sense. The fact remains that they are nested nested that way by a growing number of scientists adopting the cladistic interpretation, and I have already cited some sources holding that position.
"Aegyptopithecus zeuxis was a small primate, around 6 kg, with essentially apelike teeth, including broad flat incisors, low molars with somewhat bulbous cusps, and sexually dimorphic canines. These dental features are more similar to living apes than to Old World monkeys, but because the distinctive shearing molars of cercopithecoids evolved later, Aegyptopithecus probably represents the ancestral condition for all catarrhines."
--John Hawks, Assistant Professor of Anthropology at the University of Wisconsin
The ape family is separate from all the monkey families, so humans aren't monkeys according to the Linnaean system. When someone like Aron tells people that humans are monkeys, that's the system people are going to assume he's using unless he specifies otherwise.
But even in that system, Cercopithecids and Hominoids are both believed to be descended from Propliocid monkeys like
Aegyptopithecus, which likely resembled modern-day New World monkeys.
Aegyptopithecus
are often compared to Howler monkeys.
These in turn evolved from more basal monkeys like Apidium, one of the very earliest known monkeys known, and a potential ancestor of both Platyrrhini and Catarrhini, which includes more Old World monkeys than just Cercopithecids alone.
Apidium
The fact is that the ape family is a subset of a specific infraorder of monkeys that really are monkeys. And we are apparently inseparable from them. So humans
are monkeys.
Cirbryn said:
When I say "I don't care that you think your nomenclature is better", I'm not trying to say you have to impress me with your nomenclature, I'm saying I think it's off point. Aron keeps trying to make this an argument about whether cladistics is a better system, but this isn't about that. It's about whether it's reasonable or correct, given the system we have, to tell people that humans are monkeys or that humans are fish. You summed it up earlier yourself; it's about semantics.
Is it? Does that explain why traditional taxonomists insist on paraphyletic classification where those two words are used, but couldnt care less about terms like reptile, which theyd gladly admit are inappropriate in classification for the same reason? Why do they insist on redefining what people have always known monkeys to be to insist the common ancestor of both monkey groups somehow wasnt a monkey itself? Why strategically switch Catarrhini = Old World monkeys for Catarrhini = Old World primates? Or Catarrhini = Old World monkeys -and apes -and humans? Whats the difference? Seriously!
Here's your semantics:
"Plesion Propliopithecoidea (for 35 Ma Catopithecus and 31 Ma Aegytopithecus) is treated as a catarrhine superfamily, while plesions Victoriapithecinae (for 22 Ma Victoriapithecus) and Proconsulinae (for 22 Ma Proconsul) are treated as cercopithecid and hominid subfamilies, respectively.
...This is an especially contentious issue for primate taxonomy for the very reason that our own species H. sapiens is a primate. The traditional view considers humans to be very different from all other forms of life. Thus, this view favors retaining the paraphyletic family Pongidae for apes (Simpson, 1945, 1963), in order that humans may remain as the only living primate in the family Hominidae. In contrast, the cladistic evidence from both DNA sequences (reviewed in Goodman, 1996) and morphology (Shoshani et al., 1996) demonstrate that the African apes (chimpanzees and gorillas) are more closely related to humans than to the Asiatic apes (orangutans and gibbons) and further that chimpanzees are the sister group of humans rather than of gorillas. Thus, the cladistic view favors merging the traditional Pongidae and Hominidae into a single monophyletic family in which the subordination of its subfamilies, tribes, subtribes, genera, and subgenera is meant to represent the series of clades that arose from progressively more recent common ancestors during evolutionary descent from the stem of the family to the present. In terms of this cladistic system, if rank equivalence is sought with other primate clades, the molecular evidence from DNA sequences favors a taxonomic classification that barely separates humans from chimpanzees, placing the two sister lineages either in the same subtribe (Goodman, 1996) or even in the same genus."
--
Toward a Phylogenetic Classification of Primates Based on DNA Evidence Complemented by Fossil Evidence
Why not just admit that humans are nested within apes in exactly the same way that apes are nested within monkeys? I mean, you and I have figured out by now that humans didnt descend from chimpanzees or gorillas, or anything else in the now-defunct Linnaean taxon of Pongidae. Yet we now accept that we did descend from apes, and in fact, we are apes right now -as ridiculously deceptive and misleading as some still think that sounds.
But eventually, those of us whove studied this have come to realize that although Australopithecus and Dryopithecus and the like werent ever pongids, they were still apes by every character description applicable to that clade. Youre one of those who eventually realized this, and accepted it despite the implication in the title of this thread. When you say today that "
apes didnt evolve from monkeys", youre still limiting your interpretation of monkey to members of the modern family of Cercopithecidae, and omitting all the fossil simiiforms. So its no different than when you
used to say that "
humans didnt evolve from apes". But there is another, much older order of monkeys at the root of everything you know of as an ape or monkey now, and they were definitely monkeys also according to every character description applicable to that clade.