Just to be a pain (although you did note these are not necessarily easy to distinguish):
[quote]
Some animals such as groundhogs, chipmunks, and jumping mice enter this state of hibernation for the duration of the winter.
SOURCE: Wikpedia: Torpor
It seems now to be the mainstream view (cf. this site or Wiki) that bears don’t truly hibernate. Their heartbeat and metabolism slow down, and they can go three months without eating, drinking, urinating or defecating. But their temperature stays near normal and they can (and not infrequently do) wake up and move around.
In this view, true hibernation is a state where the body temperature is far below normal and from which it takes a long time to wake up. Ground squirrels are one example - their temperature drops to about 40F.
Pretty far back for pigs and bears: about 55-65 million years ago. These two groups began diverging shortly after the demise of the dinosaurs. The common ancestor of humans, pigs and bears lies further back, during the Cretaceous.
Of course “the Superorder level” is essentially meaningless, as “super-” this and “supra-” that and “infra-” the other thing are all utterly arbitrary. But, aside from that…you’ve got some of the relationships wrong.
Within the clade consisting of all Eutherian mammals, two groups split off. One became Insectivora (shrews, moles, hedgehogs, etc.), and the other led to Laurasiatheria & Euarchontoglires. Laurasiatheria, in turn, split into Ferae (dogs, cats, seals, bears, etc.) and Ungulatomoprpha (horses, deer, pigs, etc.). Meanwhile, Euarchontoglires split into Anagalida (elephant shrews, rabbits, rodents, and a whole bunch of other extinct shrewy-looking critters) and Archonta. Archonta, in turn, contains (or is typically considered to contain) primates and bats.
Thus, we are with primates, rodents, rabbits and bats, while bears & pigs are grouped with horses; moles not being in either grouping.
True, but all the classifications are arbitrary to some extent, so if you want to show relationships you have to lump things together in some way. Plus, isn’t it the case that above the species level (or is it genus) there isn’t a formal body to approve or diaprove classification schemes/names? So you end up having to rely on a consensus opinion rather than an officially sanctioned nomenclature.
Bottom line, is a “Superorder” any more arbitrary than an “Order”, other than that it tries to break things down more finely?
Thanks for the correction. I was going somewhat by memory.
[major aside…but then the original question has pretty much been answered anyway]
See, the problem isn’t so much the relative arbitrariness of a given classification scheme. There is certainly a subjective component in any given scheme, simply because nature is messier than we humans would like it to be. Both the Linnaean scheme and cladistics are hierarchical classifications, in which groups are nested within groups. The problem I have with Linnaean taxomonmies are the additional criterion of assigning a rank to a taxon, rather than simply naming the taxon. And those ranks are completely arbitrary (i.e., there is no objective component). Further, by complicating things by introducing rank, you actually lose information; and a classification scheme is only as useful as the information that can be gleaned from it.
The best example of this is the classification of birds and reptiles under traditional Linnaean taxonomy. Both Reptilia and Aves are given “Class” status, despite the fact that Aves evolved from within Reptilia (even the remaning hold-outs against the “birds are dinosaurs” school accept that birds evolved from within Archosauria – which are clearly reptilian). Cladistics can accomodate this fact easily; the Linnaean scheme can only do so via extreme taxonomic inflation – that is, the intoduction of numerous, superfluous ranks to accomodate all the additional nestings required to give a clear evolutionary picture. Or, it must resort to artificial groupings, and move Aves out of Reptilia, making Reptilia incomplete and obscuring the reptilian origin of Aves.
Neither case is satisfactory for many taxonomists. Better by far, I would think, to simply reference the taxon name itself, and forget all this ranking business. One gains no more information by knowing that a given taxon is ranked as a “superorder” vs. a “superfamily” because there are no fixed rules within the scheme stating that there must be so many nests above and below any given rank for it to apply.
See, back in the day, Linnaeus proposed the following ranks:
[ul]
li (there were only three kingdoms proposed by Linnaeus: plant, animal, and mineral)[/li][li]Class[/li][li]Order[/li][li]Genus[/li][li]Species[/li][li]Variety[/li][/ul]
Today, rankings have blossomed forth, giving us:
[ul]
[li]Domain[/li][li]Kingdom[/li][li]Subkingdom [/li][li]Branch [/li][li]Infrakingdom [/li][li]Phylum (Division, for plants) [/li][li]Subphylum [/li][li]Infraphylum [/li][li]Superclass [/li][li]Class [/li][li]Subclass [/li][li]Infraclass [/li][li]Parvclass [/li][li]Superlegio [/li][li]Legio [/li][li]Sublegio [/li][li]Infralegio [/li][li]Supercohort [/li][li]Cohort [/li][li]Subcohort [/li][li]Magnorder [/li][li]Superorder [/li][li]Grand-order [/li][li]Mirorder [/li][li]Order [/li][li]Suborder [/li][li]Infraorder [/li][li]Parvorder [/li][li]Divisio [/li][li]Subdivisio [/li][li]Sectio [/li][li]Subsectio [/li][li]Superfamily [/li][li]Serie[/li][li]Family [/li][li]Group[/li][li]Subfamily [/li][li]Tribe [/li][li]Subtribe [/li][li]Infratribe [/li][li]Genus [/li][li]Subgenus [/li][li]Sectio (plants only) [/li][li]Subsectio (plants only) [/li][li]Species [/li][li]Subspecies [/li][li]Variety (plants only) [/li][li]Form [/li][/ul]
All this in an effort to rank numerous clades which already have perfectly serviceable names. Saying “Superorder Laurasiatheria” provides no more information than simply saying “Laurasiatheria”.
[/ma…bttoqhpmbaa]
DF: Got it. The only information contained in “superorder” is that the grouping is larger than “order” (ie, contains more organisms), for those people used to thinking in those terms. Most people are taught the old linnaean scheme in school, so I thought it might help the OP in that sense (since he/she seems to reference that system).
But you’re right-- the rankings add no more information than the taxon names themselves. I jsut wanted to make sure I was reading your post correctly, since it could have been read to imply that some of those rankings are more arbitrary than the others.
** John Mace** writes:
That made me think of the Pig-Faced Ladies, about which I’ve read in more than one place. Here’s an account on the Internet:
http://www.thebookofdays.com/months/aug/23.htm
I’ve also read about them in the book Learned Pigs and Fireproof Women, and the Paradox Press’ Big Book of Freaks. Assuming these are correct in what they state, then:
A “Pig Faced Lady” was really nothing more than a Bear with its face shaved, dressed up, and outfitted with gloved “hands” to disguise its claws. Possible and believable. But I wouldn’t want the job of shaving the Bear.
…
Except you can’t even glean that much from the rank name. You may know that Superorder is above Order in the Linnaean scheme, but it tells you nothing about the relative numbers of sub-groups or organisms. Consider the Superorder Cetartiodactyla, which contains, as the name implies, cetaceans and artiodactyls. Cetacea is ranked as an Order, which contains 2 suborders. One of those suborders (Mysticeti) contains 4 Families, and a total of about 6 genera. The other Suborder (Odontoceti) contains 6 Families, and a total of about 35 genera.
Within Aves, consider two Orders: Coliiformes and Columbiformes. Coliiformes contains a single Family, which in turn houses two genera and six species. Columbiformes, on the other hand, contains two Families, a whopping 44 genera, and over 300 species! Two equivalent ranks, yet one houses 6 species and the other 300+. And Columbiformes alone contains about as many, if not more, species as the whole of Order Cetacea.
Again, ranks tell you nothing about the taxa, or even relative diversity between taxa. They are just an added layer of complexity, without adding any real value.
I meant to say that a single genus (actually, there are a few which could probably qualify) within Columbiformes contains about as many species as does the whole of Order Cetacea.
So, do pigs go into torpor or can they hibernate?
Darwin, I think John meant “larger” in a different sense, meaning higher in rank, not that a superorder contains more species than an order. A superorder is a group of one or more orders.
Now, back to bears and pigs.
Thing is, bears and pigs have exactly the same degree of phylogenetic relation to each other that giraffes and cheetahs do to each other. Another way to think of it is that a bear is equally related to both giraffes and pigs, and pigs are equally related to both bears and cheetahs. Bears and pigs only seem similar because both are omnivores with similar diets, habits and habitats. This is the same reason dolphins and ichthyosaurs look so similar.
The only reason we use pigs for some transplants instead of bears is that the pigs used for these purposes are about the same size as humans, and there are lots of pigs available for the purpose, since we slaughter millions of them every year.
Well, as someone who has large pigs as pets and knows how most people think of pigs, I can accept that we use pigs as donors because we slaughter so many of them and noone really cares. You’re right - if we used primates or dogs or cats or horses there would be an outcry! But, pigs - well we eat them anyway so why not? Truth is though - pigs are as potentially sociable and interactive as dogs or any other beloved pet. They are very smart. It is sad!!
I have 2 pigs, and they don’t torpor or hibernate, but they do seem to sleep a lot when it’s cold. Probably just because it’s warmer burrowed in together in the straw.
I don’t know how smart they are, one of mine continually tries to eat my shoes. 
Well, so does my dog. All of my dogs love my shoes…and socks…and anything else that smells like me. I think pigs are the same.
He did specifically say “contains more organisms”, though, which is what I was countering.
I couldn’t tell you, but I bet you could find the answer in this paper: Heldmaier G (1974) Cold adaptation by short daily cold exposures in the young pig. J Appl Physiol 36: 163-168
I don’t think we diagree about any of this. It’s just a matter of how much detail you want to go into in explaining to the OP where the relationships lie. If someone is familiar with the KPCOFGS classification system, and you tell them two organisms are related at a level above Order but below Class, that does convey information without getting into all the Latin names for the various taxa (which some people find confusing).
I didn’t mean to imply that every taxon had the same number of species in it-- only that the higher the rank, the more species within a given lineage.
Anyway, we’re getting way off topic from a rather odd question in the first place. (No offense to the OP, as it’s a legitimate question, just seemingly odd to pick “bears” out of the hundreds of different animals that might be considered instead.)
My pigs were in a warm, heated house during the winter and they still slept for most of the day. And night. I don’t think it was about cuddling up and staying warm - they were warm. Plus they had 3 goats that slept on them. Everyone was warm. No, I think there is something about pigs sleeping more when there is less sunlight.