Valentine Pontifex

Zetec:

If, of course, we are using cladistic classification and classify only on the basis of evolutionary relationships.

Oolon Colluphid

Yes, but it’s not necessarily circular, cos it can also be done by simple homology (ie how the hell else do you tell what’s in a ‘kind’?). It was nice and easy for creationists when they set the limits at ‘species’... till we started showing them speciation. Now they have to place the divide higher and higher up the taxonomic hierarchy. If sharks are fish (ie of the same kind as teleosts) despite not-so-subtle differences like not having bones, swim bladders etc, then the point does stand: if they are all of the fish kind, then there’s no reason to exclude humans from the ‘kind’ that includes the other highly intelligent, tail-less, tool-using, facultatively bipedal, branchiating primates.

Hey... ForwardlookinFoodcookin*Omni-eatinRival-beatinTool-usinTail-loosinTall-walkinNearly-talkin**Arm-swinginCleverthinkin -– Primates!

I doubt this ad campaign will catch on though.

* Well, washing it at least
** Slight exaggeration, but chimp societies are based on very complex communication, and whatever their faults, the attempts to teach them sign languages show they do seem to have remarkable facility with abstract symbols.

Cheers, Oolon

Peez

All I seem to have time for these days is to pick nits, here I go again. The Phylum Chordata includes all animals with a notochord, dorsal hollow nerve cord, pharyngeal slits (gills), and a muscular postanal tail at some stage of development. It is typically divided into three subphyla, one of which is Vertebrata. The vertebrates include the following Classes: Agnatha (the jawless fishes: lampreys and hagfishes), Chondrichthyes (cartilagenous fish: sharks and rays), Osteichthyes (bony fish: from guppies to tuna), Amphibia (amphibians: salamanders, frogs, toads), Reptilia, Aves, and Mammalia. The latter three should be included in a single unit (the Amniotes). There are also several extinct classes.

Peez

tgamble

Another creationists gem:

ps418

"Archaeopteryx cannot be said to be transitional if it cannot be shown to have offspring."

That is, unless you define a 'transitional form' in terms of morphology, like paleontologists do. Creationists are free to define transitonal however they like, of course. Archaeopteryx may be one a direct line of descent with modern birds, or it may be one a close side-branch. Either way, the existence of a genus with both avian and dromaeosaurid characters is excellent evidence for a dromaeosaurid ancestry for aves.

Peez

That must have been my evil twin.


Peez

Tharmas

I defer to the expert...and I think we HAVE to nit-pick. After all, what we’ve got going for us is precision.

Grumpy

zetek,
According to that diagram, sharks are most closely related to roosters. And apparently horses are the transition between salamanders and tortoises.

Or maybe I'm not reading it right.

theyeti

You're not reading it right. Start from the left and follow the braching lines toward the right. Sharks are most closely related to #7, which looks like skates and rays. They are equally related to all of the taxa below, including roosters, horses, and other "fish". (They share a common ancestor at node # 5 -- all of the below taxa share the same common ancestor with the shark, thus they are equally related)

[edited to add:] Keep in mind that the purpose of that cladogram is to show what we call "fish" and their relationships to each other, as well as to other vertebrates. That rooster that you see actually represents a huge tree containing all of the birds. Likewise, that horse represents all of the mammals, including us. Also, at each "branch point" (aka node) which group is placed on which branch (top or bottom) is arbitrary. You could rotate the cladogram about any node and it wouldn't make a difference. For example, you could rotate node # 24, thus exchanging the place of the birds and crocodilians, and it would be the same. Likewise, you could rotate node # 18, such that the turtles would be "closest" to the sharks and the birds "closest" to the mammals, and it wouldn't matter.

theyeti

[ February 07, 2002: Message edited by: theyeti ]</p>

pangloss

Ok, Ri....


HYes - evolution can create information.

Kimura demonstrated this in a paper in 1961.