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Message 303 of 331 (654198)
02-27-2012 6:26 PM

Linnaean taxonomy is arbitrary
Creationists do not do themselves any favors by trying to hitch their idea of "kind" to Linnaean taxonomy (LT). The problem is that LT can be just as arbitrary as kind above the level of species. If any creationist hopes to develop a solid working definition of kind then they need to move away from LT entirely. Cladistics is a much better system.
What is stopping taxonomists from putting chimps and humans in the same genera? Nothing. They are free to do so, and even Linnaeus himself considered it. What is stopping taxonomists from putting orangutans in their own family and gorillas, chimps, and humans in another? Nothing. As long as the relationships between the families is correct then LT allows for tons of different possible organizations of those species.
If the creationist model has any hope of working they need to describe kind in terms of physical and genetic comparisons. Pointing to the LT Family level and saying "somewhere around there" is not going to cut it.

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Message 306 of 331 (654422)
03-01-2012 11:22 AM
Reply to: Message 304 by Chuck77
03-01-2012 1:35 AM

Admittingly tho, i'm not too familiar with Linnaean taxonomy as compared to Cladistics, (or with Linnaean taxonimy at all) but from what has been talked about concerning Cladistics, it seems a good route to go.
Cladistics is based on shared and derived features. The root of a clade is the synapomorphy which is the list of shared characteristics. Each branch from that node is defined by their derived characteristics, features that are not shared with the rest of the clade.
It is an elegant system at its most basic. However, shared and derived features can be hard to determine at times due to convergent evolution and loss of ancestral traits.
You will also find that designed things do not easily fall into a nested hierarchy when using cladistics. We could use playing cards as an example. What are the shared features in playing cards? First off, all of the cards share the same rectangular shape, so the synapomorphy of the entire playing card clade is the rectangular shape (the characteristics shared by the entire clade). We have two colors so we have a red clade and a black clade which are derived traits. In the red clade we have two suits, and also two suits in the black clade. The synapomorphy in the red clade is the red color of the suit. The derived traits are diamonds and hearts. In the black clade, black is the synapomorphy while spades and clubs are the derived traits. How do we divide each clade further? The only thing left is the rank of the cards. This is where we hit a problem. We find the same rank (i.e. Kings, Aces) at the ends of SOME of the clades. At this point, the nested hierarchy fails. There are features shared by some cards in the diamond clade and the club clade that are not shared by all of the cards in the heart and spade clades.
Does this help in understanding how cladistics works? Do you understand how a nested hierarchy is falsifiable?

This message is a reply to:
 Message 304 by Chuck77, posted 03-01-2012 1:35 AM Chuck77 has replied

Replies to this message:
 Message 309 by Chuck77, posted 03-15-2012 3:39 AM Taq has replied

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Message 331 of 331 (656590)
03-20-2012 11:25 AM
Reply to: Message 309 by Chuck77
03-15-2012 3:39 AM

Sorry it took me a while to get back to you. Love your new approach to this debate.
Taq writes:
Cladistics is based on shared and derived features.
Chuck77 writes:
Ok, but to what extent?
The entire thing. That is what cladistics is, the organization of life based on shared (synapomorphies) and derived (apomorphies) features.
I would suggest that you play around with Tree of Life Web Project. You will see that life is organized into a branching structure, the "tree of life". This tree is entirely based on shared and derived features. You will notice that nothing with teats or fur is found in the aves (i.e. bird) tree. You will also find that nothing with feathers is found in the mammal tree. So what would stop God from creating something with teats and feathers? Bats seem to get along just fine lugging around mammary glands, so why not give some of those bats feathers, or some of those beaked flying creatures teats. I can't see any reason why God could not do this, but there is every reason that evolution would not since there is no way to move adaptations from one branch to another (at least for metazoans which do not participate in any meaningful horizontal genetic transfer).
And yes, this does extend to genetics. We see that a comparison of genomes reflects the same trees that are constructed based on morphology. This is even true of DNA that is NOT involved in morphology, including pseudogenes and mitochondrial genes. Again, there is nothing stopping God from giving yeast and humans the same cytochrome c gene while giving chimps and humans very different cytochrome c genes. There is no expectation of this nested hierarchy where special creation is concerned.
To help explain this better, let's look at cars. Cars do not fall into a nested hierarchy. For example, the first car available for sale with airbags was the Oldsmobile Tornado (source). If cars were like life, then only the descendants of the Tornado would have airbags. What do we see instead? Airbags began appearing in all lineages of cars. This prevents cars from being organized into a nested hierarchy. We can also see instances where Subaru's have Porsche Boxster engines, and Fords having Chevy rims. Designers are free to swap design units across all designs. Therefore, a nested hierarchy is never expected from such a design process, and this applies to special creation as well. Only a process like evolution is expected to produce this pattern of shared and derived features.
Yeah, the cards can't really be broken down anymore...what's left? I might say ask the person who made the cards to find out what they were thinking. Tho, the cards should say something themselves, but seems all the cards are the same, with slight to more modification. Where does that leave us...
You failed to really get the gist of my example. I was showing how playing cards do not fall into a nested hierarchy.
I wonder why it's so difficult. There should be something that either seperates the species or brings them together...why is the line so blurred? Or is it not blurred at all and they are very similiar yer very different?
There is something that brings species together which is their shared features. There is also something that separates them which is their derived features. The line is blurred through time because of evolution.
A little yes, but I don't know how a nested hierarchy is falsifiable.
The card example shows exactly that. When you find features in separate branches that are not found in the nodes of those branches. Using the avian and mammalian clades examples include a creature with feathers and teats, feathers and three middle earbones, flow through lungs and fur, etc. Feathers, three middle earbones, and flow through lungs are derived features of mammals and birds. They were not found in the common ancestor.
Edited by Taq, : No reason given.

This message is a reply to:
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