Lesson 11/16: Biological Systematics Part 1

I never said they were useless. But they are clerly vestiges of legs.  This can be confirmed by identifying the genes. In some cases, these genes are reactivated and develop a more complete complete set of legs. You are basically saying that a broken stapler used as a paper weight doesn't mean that it once a stapler. Wrong!

No. You are the one assuming the stapler is broken. It's not. It fully functional, and it's not a friggin' stapler.

If you find a old PC, like a radio-shack TRS-80, being used as a doorstop, only a fool would think it was designed for that purpose. Since we can show that similar designs, which are functional, are used to perform other (primary) functions, like computing, we can safely say that the broken machine is not optimized for holding doors open. It is simply being used because it can no longer serve its original function. This is the case with anatomical and molecular vestiges.

One again, your metaphor is invalid based on the assumption that machine is "broken" or somehow inferior. Is procreation an inferior purpose than walking? Further more, you are assuming that that was it's original purpose, simply because the bone looks similar.

And because the genes are similar, and because cetaceans have thousands of olefactory genes even though they have no sense of smell, and because the evolution of artiodactyls to cetacean is well documented in the fossil record, even the nostril to blowhole and air to water hearing transitions, and because marine mammals have hair follicles that no longer produce hair, and because when they swim, they move their spine up and down using muscle groups analogous to running mammals, and because...

Perhaps, but species are not classified based on characteristics observed at the cellular level. Cladistics is only based on morphology and genetics.

I'm curious to know exactly what you mean regarding the cellular level though.

I think the automobiles analogy may fail because its variation of the same "kind" (automodiles). Sorry for the not so scientific terminology. What would happen if you did the "common design vs. common descent" analogy with a broader category like electric kitchen appliances?
-Coffee grinders, blenders, food processors
-Convection Oven, toaster, microwave
-coffee maker
-etc.
?