*Edited for numerous typos and blurbs resulting from posting at too late hours, and/or amid too many distractions.
Cirbryn said:
Well, being the wacky and tenacious guy I am, I thought I’d go through these last bunch of posts and respond while I can. Now that Aron's left the thread I just might have a chance to catch up.
Just when you thought it was safe to go back in the water...
If you require that all groups be monophyletic (and thus include all descendants), how are you going to represent the relationship of a parent species to a daughter?
Aron-Ra said:
Just the way I've explained to you nearly a dozen times now; mark the emergence of the new characteristic without pretending that some of the old family trees you subjectively choose stop where the new family trait begins.
See, these condescending references to previous posts in which you’ve “explained” all this, but which you can’t be bothered to cite, is something I’m really not going to miss.
You mean; 'can't be bothered to cite it again'. After doing it so many times already, I've given up showing you where I said everything I've already told you before.
You “explained” in post 262 that “If dachshunds ever became a new species, they would be a new species of dogs, Canus lupus familiaris dachshund.” That is incorrect, as I’d already pointed out in post 166 (which you ignored).
I didn't ignore it. I never ignore anything the way you admitted you do. You were, -and are- wrong. Dachshunds as a new species would still be dogs, and you still can't defend your assertion that they would not be.
You claimed in post 328 that cladists can tell whether they’re talking about the progenators of a clade vs the entire clade based on context. I’d expect that’s generally true, but it still leaves the daughter species as a member of the parent species even though the two no longer interbreed.
Not so. As I said before, referring to the question I just answered for you, we represent the relationship of a parent species to a daughter by marking the emergence of the new trait, which can be recognized as a new species. Its not the same species it was before, but its still a member of every clade that species belonged to, and that has been my main point throughout this entire thread from the beginning.
You also talked in post 328 about snakes meeting the description of tetrapods “in addition to the loss of limbs”, and when I pointed out in post 346 that was nonsensical you agreed in post 357 that snakes don’t retain traits involving limbs, but added that the clade isn’t defined by the traits.
Are you deliberately misunderstanding this? Are you trying to confuse me? I can't understand where you're coming from on anything. None of your arguments have made any sense since the onset of this discussion, and this doesn't either. If we pretend for a moment that paraphyletic groups have any point or purpose, you must still admit -surely- that there is a phylogeny for snakes that is marked (in small part) by these labels; Squamata, Anthracosauria, Tetrapoda, Stegocephalii, etc. Each of these is characterized by a single most common or obvious trait. Squamata = having three eyes, Stegocephalii = having fingers, Anthracosauria = having five fingers, tetrapoda = having four limbs, almost none of which apply to snakes anymore. Somewhere back there, there is probably a single ancestor for everything with blinking eyelids, and that wouldn't apply to snakes anymore either. But even without any number of toes on any number of legs, we can still tell by the rest of the form exactly which lineage snakes belong to. None of that information was lost, and not just because the first snakes were already definitely snakes in every respect even when they still had legs. That's what I meant all those times I kept repeating that even the biggest leaps of macroevolution are still just a matter of incremental, superficial changes slowly compiled atop various tiers of fundamental similarities, and that this is why those successive levels of similarity represent taxonomic clades which encompass all the descendants of that clade.
All of which is well and good, but a species is defined by a trait, and that trait is gene flow. The emergence of a daughter species doesn’t simply mean the emergence of a new characteristic. It means the loss of the defining characteristic of the parent species.
No, you're still wrong, and you're ignoring the reason why.
Every species is (normally) genetically isolated from every other. Every member of a species is a potential interbreeder with every other member of that species. But except in rare instances, members of daughter species are not potential interbreeders with members of parent species.
If all other intermediate dog breeds between mastiffs and dachshunds were killed off tomorrow, mastiffs and dachshunds wouldn't breed under normal conditions, and that is the defining characteristic of species. But nothing has changed in either breed, and it wouldn't be that dachshunds wouldn't be dogs anymore and mastiffs would be. And it wouldn't be that mastiffs wouldn't be dogs anymore if dachshunds were. Both of them would still be dogs even if one or both breeds were deliberately isolated from all other dogs until they were no longer genetically compatible.
Fail to define the parent species in a manner that excludes the daughter (as a purely cladistic system would have us do), and you leave out that crucial information.
Once again, (and I can’t be bothered to cite where I’ve told you this before, but) as I've already explained so many times, we represent the relationship of a parent species to a daughter by marking the emergence of the new trait, which can be recognized as a new species. But we don’t pretend that any of the old family trees end where the ones begin because it simply does not work that way in real life.
And no one is pretending that the family tree stops with the new species.
Then the dog family tree doesn’t end where dachshunds begin? Does the monkey family tree end where apes begin? Or would you now like to contradict what you've just said?
Nothing in Linnaean taxonomy suggests that cladistic information is incorrect, or that a daughter wouldn’t be in the clade of the parent.
Hallelujah! We’re in agreement at last! Thank you! And despite all your self-conflicting whining below. Is this your second admission that humans, like all other apes, are highly-derived monkeys after all? Or would you like to contradict yourself again so you can continue trying to deny that?
The Linnaean system merely provides information about the genetic isolation of the species that a purely cladistic system does not.
No. Instead, the Linnaean system conceals information that is only available in clades. For example, you and SLP have both finally agreed that our ancestors were in fact monkeys, but the Linnaean system would have us say “monkey-
like” if we refer to extinct monkeys considered ancestral to apes, and only use the word, “monkey” when describing a lineage that didn’t lead to our own. Did you forget about the concensus reached by those hundreds of taxonomists at the PhyloCode symposium? Why do you keep ignoring the fact that even those few scientists still arguing from your perspective have publicly and loudly admitted that Linnaean taxonomy cannot currently reflect evolutionary relationships, and that your system will need a "serious overhaul" before it even can?
No no no. As I've told you several times before, with monophyly, you retain all the information of the parent clade, and all the information for each divergence in it, including the addition of the trait you're trying to point out here. Don't limit all your conversations to species only. We're talking about whole family trees here.
I have no idea what you mean by all the information being retained, and I don’t think you do either.
Then I have overestimated you again. I have already explained this above, so I obviously understand it. But as I’ve had to repeat all my explanations to you so far, why wait until tomorrow?
If snakes lose their limbs, then the “information” provided by the morphology of limbs is not retained.
Imagine for a moment, that we never knew anything about any true snakes which still had their legs. Does the absence of those limbs imply that snakes might belong to any other group besides Stegocephalli, Tetrapoda, Anthracosauria? Or was there still ample information retained that we could easily identify them as members of Lepidosauria, and more specifically, Squamata? In fact we did so decades before we ever discovered
Haasiophis terrasanctus or
Pachyrhachis problematicus. How could we have done that if that information was lost along with the limbs? Obviously, it wasn’t.
If daughter species lose the ability to interbreed with the parent, then that ability and any information associated with it, is lost. The loss of such defining characteristics is important to note, particularly with species.
Once again, there is no loss of defining characteristics. Even the loss of limbs is a gained trait in taxonomy. And I can’t be bothered to cite where I’ve told you this before either; But don't limit all your conversations to species only because we're talking about whole family trees here. The term, 'paraphyletic' doesn’t apply to the species level. Whether humans are apes, or whether apes are monkeys, or whether birds are dinosaurs or reptiles, or whether snakes are lizards, (or tetrapods) etc., etc., -none of that has anything whatsoever to do with the division between species, and I’m arguing against its use at any “taxonomic level” (parent clade) “above” that.
I might as well just write one response to you and cut-and-paste it into this thread every day because I keep telling you the same things over and over again only to see you show no knowledge of it tomorrow.
Or here’s a thought: why not try getting over yourself enough to realize you are expressing an opinion, not imparting knowledge to be memorized.
Because (and I’ve already told you this several times too) I’m not talking about opinions here. I
am imparting knowledge because I’m only talking about what can be objectively demonstrated. Humans are monkeys for all the exact same reasons we are apes; We descended from apes / we descended from monkeys. There is a definite genetic link too, since our genes are 93% identical to that of rhesus monkeys for example. SLP has already admitted that it is technically correct, -cladistically- to classify humans as monkeys, and the Linnaean taxon, “Simia” translates as “monkeys” literally. Common definitions of monkeys include apes, and technical definitions of monkeys still include humans too because every character trait descriptive of all apes inclusively (and exclusively) applies to us, just as every character trait descriptive of all non-hominoid monkeys also applies to humans as well. There are no characters common to every known species recognized by scientists as “monkeys” that is not also shared by humans and/or other apes, and there is no definition that sets them apart from us except a colloquial one which actually says “all of ‘them’ –except us”, and that is just a Freudian admission that “we” are one of “them” after all. All of this is objectively verifiable and undeniable and not one bit of it is opinion. But your whole and sole contention to all of this is limited to opinion by your own admission, and by the admission of others pleading for your same position. Don’t try to project your own faults onto me for I will not have them.