I think it's an important topic to consider - why would the dysfunctional Vitamin-C gene shared between humans and our closest primate cousins advance the case for the evolutionary model, but dinosaur/human related tracks wouldn't advance the creationism model?
Simply put - Coherency
Does a heap of metal parts thrown onto a pile constitute a "machine"? What if we assemble the parts together in some fashion where the metal parts can start to do something as a whole? Now we have a machine. The machine, as we've conceived it, is a coalescence of each individual part - each of which is important for the function as the whole. You could say that the parts, as organized/bound/connected together, are "coherent"... whereas a heap of disassociated metal parts is not "coherent."
Conceptual models are only useful, and even demonstrable, if they're coherent.
Let's say my model for why the universe was constructed by a sentient can of stewed tomatoes is as follows:
- We have a book that makes that claim.
- The book also claims that ice cream is tasty.
- The book also claims that Thursday comes after Wednesday
- The book also claims that humanity and chimpanzees split about 6-8 million years ago
Now, if we were to demonstrate that parts 2 through 4 were true, would that mean that part 1 is true? Would that mean that the model is true and accurate? I'd say no, because what do any of the premises have to do with each other? They're disconnected, disassociated and unrelated.
This not a model of any value.
Believe it or not, but we do actually have people doing this. Here's their model.
- We have a book that says an invisible sky wizard made the universe and everything within.
- The book also claims that the Earth was globally flooded.
- The book also claims that events took place in some historical cities.
- The book also clams that humans cohabited the Earth with dinosaurs
- The book also claims that the Earth is between 6-10 thousand years old
We have these people, "creationists", who are attempting to demonstrate that #1 is true by demonstrating that the other premises are true... even if they have no cohesion beyond the simple fact that they're all stated within the same book.
It's a straight-up Association Fallacy... and that's the core of their "model."
... whereas the dysfunctional Vitamin-C gene we share with our closest relatives is a direct demonstration of a coherent model of evolution - descent with modification and natural selection - where shared traits through common ancestors is one of the key distinguishing aspects of the model. What could be a better demonstration of common ancestry than common traits, particularly when those traits are confined to specific sub-trees, as would be expected if it were true?
My question to the creationists would be - what would distinguish a created Earth from a non-created Earth? How would you directly support that the Earth was created? Not that it's old, or that evolution is false... how would you demonstrate that Earth was created?
It's really tough to keep these people on task.
If they can start to answer that question, maybe they can also start to construct a coherent creationism model.. and then we can actually have a productive discussion about it.