taxonomy and what makes... (Darwin, Earth, dinosaur, Kingdom, evolution)

[painted wolf]

a class a class...
or a genus a genus...

I have been reading Donald Johanson & Maitland Edey's book on Lucy lately and it really struck a cord with me.

One of the big things Johanson brings up is where do you draw the lines between groups? What makes a human a human and an ape an ape? It was one of the biggest issues that he stuggled with when he was working with Lucy and the other Hadar hominids...
How different can something be and still be part of the genus, order or class?

For instance where do you draw the line between dinosaurs and birds? What makes a bird a bird but a dinosaur not a bird?
The lines are blurry at best, and its probably the most difficult question of taxonomy. Infact its the whole premice behind modern phylogeny: that distinct lines can not be drawn between the part of the tree of life.
Phylogeny is still fairly contriversial... paleontologists are the primary proponants while Zoologists are the primary desenters.

Honestly to me this reflects the nature of the work each does... Paleontologist work to find ancestors and thus are more exposed to the changes in the past.. they have more experience with the species that make the lines in the sand so blurry or wipe them out all to gether. Zoologists are more concerned with living animals and are specalists in thier particular Class... Ornithologists, Herpetologists and so on...
It can't be denied that Phylogeny is a bit of threat to that older system... Ornthologists can get very perterbed at the idea that thier birds are "simply" living Dinosaurs who are "reptiles".... Somehow to some it makes the birds seem less "special"

So I guess the point of this little rant is... Can such lines be drawn knowing what we do today about both the fossil record and Genetics?
Is it really worth all the hassel to change a system that has been in place for over a hundred years.. a system that is the cornerstone of how we name and classify all life on Earth?

wa:do

Ps... first thread happy dance!!!

[michel]

I know very little about what you are talking about, though I get the gist. There is a modern tendency to 'label' everything and everyone; labels have to be new and sound impressive; I guess the old trusted methods are just out of fashion; what do you think ?

[Sunstone]

I agree with Michel that there is a human tendency to name and label things. In practice, that sometimes means that we create distinct categories that are based on nothing more important than semantics, as when (perhaps) we differentiate between birds and dinosaurs.

I suspect that the category "Homo" should be extended to our nearest relatives, the chimpanzee and bonobo. Although they are in a different genus today, they share so much in common with us that it seems artifical to make such a sharp distinction between them and us.

But I don't have much hope that chimpanzee and bonobo will be given the designation "Homo" anytime soon.

[Terrywoodenpic]

Taxonomy is a hang over from the victorian need to collect and classsify every thing.
It is a help to thinking an learning, but can never hope to be totally accurate.
One day a more accurate system based on Genes will be developed.
Which would also give the historical perspective.

A name should be just a name, it should not be part of the classification system.

Like if you have a filing system.
New files should be given an un-changing number. only then should you start classifying,
if every thing references back to the number, you won't lose anything however many times you reclassify,even in a manual system.

Terry____________________-
Amen! Truly I say to you: Gather in my name. I am with you.

[painted wolf]

he he.. sorry I was on a biology high and forgot not everyone is there with me..

Taxonomy is the way life is classified for scientific reference.
There are different ways this is done...
Linnean- in which everyone gets a two part name and you have the classic list
Kingdom, phylum, class, order, family, genus, species.
Cladistics- everyone is in clades or groups of inter-related branches of a tree of life so to speak.
this is still new and they are still working on particulars of how it should be arranged.
granted new is the 1960's... science doesn't always work quickly after all.

some helpful links:
http://en.wikipedia.org/wiki/Scientific_classification
http://en.wikipedia.org/wiki/Cladistics
http://en.wikipedia.org/wiki/Phylogenetic_tree

part of it is fashion... part of it is refecting how much we have learned since Linneaus came up with his system back in the 1700's. In his day evolution wasn't an issue, everything that lived now had always lived on Earth since "the days of the garden of eden". Everything was part of a grand system that god had made whole and unchanging. Cats were cats and dogs were dogs and never would the two ever mix.
Well fossils and Darwin changed all that.

Now the question is where do you draw the line between say the Dog and the Cat? How far back can you go and still be able to tell the difference?

wa:do