Posted by
Michael on Sunday, October 26, 2008 11:56:43 PM
The following is a response to Rob Sheldon's post . It was originally intended to be a comment, but it became much too long.
Rob:
What is your source for that conclusion on the time required for a cell to form? More importantly, why did it involve single atoms randomly combining rather than amino acids, which, as we have nown since the fifties, can form from chemicals present four billion years ago (I know that they did not form the entire atmosphere, as was thought at the time, but there still would have been large quantities of them around volcanoes)?
Chihuahuas and great danes are in the same species because chihuahuas can breed with other breeds, which can breed with other breeds, etc. until you get to great danes. If the only breeds of dog were chihuahuas and great danes (I am assuming that they cannot breed) they would probably be separate species. Mayr's definition of species has exceptions in the animal kingdom, but when they are made, they are to split populations that can breed into separate species. Under what definition of species are two populations that cannot breed the same species?
There are actually plenty of found links in the fossil record. For examples, see talkorigins.org, the Understanding Evolution website, and the Fossil Evidence ssection of the website for the Nova episode Judgement Day. While at that last site, also see the In defense of Evolution section for what I consider to be the single best piece of evidence for evolution (it's the part about telomeres and centromeres).
I do not see how punctuated equilibrium is a problem for evolution, inasmuch as it is a modification of, not a replacement for, Darwin's theory.
I assume the "problem for evolution" regarding the Cambrian explosion is the supposed total lack of predecessors. There are, in fact, several probable predecessors to later animals in Precambrian strata, as you can see at the University of California Museum of Paleontology Vendian Animals website.
Until recently, you would have been correct in saying that there are no known Jurassic feathered dinosaurs (not counting birds as dinosaurs). Ths would not have mattered, as Archaeoopteryx is itself a found link and cladograms constructed on bases other than feather structure show that dinosaurs less closely related to birds have more primitive feathers (see the March 2003 Scientific American article "Which Came First, the Feather or the Bird?"). However, a feathered dinosaur from the Jurassic called Epidexipteryx has recently been discovered, so your point is not only inconsequential but incorrect.
Finally, if the thesis of Expelled is merely that ID poponents are "denounced" (that is, criticized for having no evidence and trying to pass off a religious belief as science), then that alone would make it laughable even by creationist standards. If the thesis is that ID proponents are suppressed, my point remains (and see expelledexposed.com to see that this is not the case).