Why heirarchical taxonomy? Linnean system vs. Phylocode?

Howdy.In another thread one poster made reference to another's usage of the word "man" or "mankind" and asked him why he used that phrasing. It seemed to the other poster that this was similar to using the term "kind" as YECs do when talking about the ark story. The poster then explained that he used the term "man" to describe anything in the genus "homo." So what he was saying (even though he didn't mean to) is that "homo" is a sort of Biblical "kind."The classification of a species usually relies on the ability of an organism in a species to interbreed with other organisms of the same species. If two organisms can't interbreed then they are of a different species (you know, and they are of opposite sex and reproduce by sex, and are sexually viable). Even though some individuals of what we classify as species can interbreed, say members of the cats or dogs, and some others. Yet we put them into separate species for whatever reason.In this regard, the Linnean heirarchical classification system seems to be largely arbitrary in many places, especially to a non-biologist such as myself. So that the term "genus" (maybe even other types of division) really could be supplanted by the term "kind".My question is this: Why continue to bother with the heirarchical Linnean classification system when sometimes it seems that assignments to certain genuses and species seem arbitrary and use the same type subjective classification used to assign species to a certain "kind"?What I mean is this: Say a paleontologist discovers an extinct species of bear. What is the difference between how he assigns this fossil to the genus "Ursus" and how a creationist would assign it to the kind "bear" (or some other name)?Should we start using this Phylocode or some other non-heirarchical scheme?

Yeah, I have that issue.

What I meant is what does a biologist do in order to say "this goes in genus ursus" and how is that different from a biologist who might also be a creationist saying "I could put this in kind 'bear'" which to me is only a name game.What features let us differentiate with the current system? What thought process goes into putting a specimen into a certain genus and is it as "arbitrary" as someone who also had a similar heirarchicy but just happened to have the category "kind" instead of "genus." Well, from what I understand, in order to make it fit 99%, people had to invent new categories like sub-phylum, super-class, sub-species and things like this. It just seems really slapdash and not very adaptable to new knowledge. All these sub-divisions and such get really hairy and confusing. This is exactly what someone would do if they wanted to classify a specimen as a certain "kind." They have a framework of other species that we call bears based on the construction of the skeleton and other features. To me this seems kind of subjective. It may seem less subjective to "the trained eye." I would imagine that a biologist will also say "it's a bear." Let's say hypothetically that the biologist is a creationist and he does all the other things that a biologist would do to classify the specimen as a bear, but instead of using the Linnean classification system, he just says that this specimen is of the bear "kind." How is that so different than putting him in the genus ursus? If the alternate classification scheme was also heirarchical then "kind" could come under "variety" and maybe "type." It would be the same thing but would stick to the literal Noah story.Yeah, and from what I understand, the iridium layer is spotty around the world but when it is found it's always at the K-T boundary. Are you talking about Phylocode?
Well, the Linnean system doesn't provide any more information than a similar system under a creationist framework with the names changed.
It doesn't provide information on the linneage of the organism in question. The way it's set up, it's as if all organisms could be alive at the same time and it would still work the same. Yeah, that's what phylocode would be better at doing than the Linnean system. The Linnean system (and this may be the whole point of this thread I think) was invented before evolutionary theory took off and is in essence a creationist system. Or, it would be identical to a system devised by a creationist that happened to have the classification "kind."

Exactly!The Linnean system goes to hell in some circumstances.
Sometimes there are just too many differences to just cubby a classification into a specific ranking.From what I read in that Discover article ( I had heard of Phylocode about a year before, but anyway... ) the people who like Phylocode are the ones working in fields where the old system is most problematic.The ones who are against it are the ones working in fields where the Linnean system works.I think it was the insect people versus the mammal people.

I know above I said the Linnean system was identical to a creationist system, but I did forget that the heirarchical scheme of it became a sort of evidence for common descent. But I still think that the Linnean system would work whether there was common descent or not. I may be totally wrong, but the way it seems, the system could work if every organism ever alive was alive today (crap, but so would phyolocode ) Yeah, this is the kind of "arbitrary" subjectivity I was talking about. New knowledge comes along and it becomes really hard to change the classification of an organism. It's like someone looked at it, evev fully characterized it in every way, measured everything and then some, but the final shelving into a cubby with a name on it is pretty damned subjective it seems. Ah! Thanks for that! I was hoping someone would give me some validation for my concerns.

I think it's finally clearing up for me.
I keep thinking of the way a creationist might think in my biased evolutionary way of thinking. It never occured to me that a creationist would not want to make a heirarchy because that would then suggest to him a common descent.Now I wonder, since most creationists must have encountered at least the classical Linnean system in school, do they reject it?I guess there is no real need to reject it since it doesn't necessitate common descent, it only implies it. One could still use the Linnean scheme and just say that it's based on physical similarity (as I guess it was done before evolutionary theory was applied).BTW, I haven't heard from a creationist on this. I was hoping they could clear up my misinterpretations of how an organism might be placed into a certain kind.

I usually start thinking about cat hydrids, which are usually fertile.In the wild they never really interbreed, because of social order, but they are capable of interbreeding with other species in the cat family. I guess the only reason they are separate species is because they wouldn't normally mate in the wild (that and the fact that humans don't breed them very often is the reason it's rare).Then, I don't know if cattle and bison are put into separate species, or if breeds of domestic cattle are put into separate species either.And something like african wild dogs are a different species from domestic dogs as are wolves ,but I think all can interbreed and produce fertile offspring.Then there's the other direction. I'm also not sure if they've given lab rabbits a new species because after being bred in captivity all these generations they can't interbreed with wild rabbits. I guess that's not the same and only an example of observed speciation.Anyway, this just reinforces my belief that these classification systems, at least at the species level is kind of hard to nail down objectively. It's difficult to assign certain types of animals (don't know the other kindoms) to a specific species and another to a different species. The basis for the assignment isn't entirely concrete.

Maybe people are missing the point of the thing.
I guess I wasn't clear in that I was hypothesizing a system equal in scope with the Linnean system or Phylocode, but it has as a division of classification "kind" instead of something like a genus or maybe even an order. Perhaps it would not be exaclty equivalent to either but required some other criteria to fill it. It would be in a heirarchy just the same as either Linneus or Phylocode and would describe ALL life. It would just have the term "kind" in there, so as to stick to the Bible, and thus making the Bible more accurate in some way (as long as there was some sort of accelerated evolution that took place right after the flood and does not happen today). Praise be to them. All glory and honor are theirs, forever and ever. But really, there has to be a limit to the objectivity, especially at the species level in lots of cases.

What do you mean they don't exist?
Do you mean in real life, or in my hypothetical creationist classification system?I guess they don't have to exist.
There would be other categories with other names.
"Kind" would be one of those categories.The point is not to add things or subtract things from existing systems. It's to divise a system that has a category "kind" that is equal in scope to existing systems.

That is an interesting thought. It never occured to me how we would classify extraterrestrial life once we do actualy find some. Do we stick it in with the earthly critters if they look similar, or do they get their own kingdom etc? Hmmmmmmmmmmmm................