"Can someone please explain to me the problem of teaching multiple, scientific theories of the beginnings of the earth in public schools?"
Sure. Just come up with an alternate hypothesis to the currently accepted model, do the research that finds the data that supports your hypothesis, present your data to scientists around the world in the appropriate journal and wait for them to pick it apart or come to the same conclusion by repeating your experiments and data collection. Once all that is done you'll have your "competing theory" which will either supplant the currently accepted one or, more likely, modify it so you'll more than likely still end up with only one theory.
Happy now?
"Evolution, as a stand alone explanation for all life on earth has been repeatedly found lacking (e.g. no transitional forms, the problem of infinite regression of causes, lack of vestigal organs) as a single explanation."
This is like saying that the theory of relativity doesn't explain how the stock market works. Since evolution doesn't explain "all life on earth" it is, obviously, going to be found lacking when you use it for such questions. It assumes, with a damned good reason, that life is already here and proceeds from there to explain the diversity of life, not how it arose.
"Why should teachers not be allowed to point out these deficiencies and point to other theories, like intelligent design, that propose solutions to the problems."
They're perfectly free to point out such things. It may help to plant the seed of a biologist for the next generation by showing students that there are still things to be discovered.
Intelligent Design, by the way, isn't science and doesn't belong in a classroom. It proposes no hypotheses, makes no predictions, gathers no evidence and performs no experiments. What is there to teach other than propaganda?
"And before you attack me as a religious zealot, please take note that intelligent design in no way implies which "intelligent" agent designed life."
Uh, that's precisely what it implies. In fact, it explicitly states it. Hell, the name of the bullshit says as much.
"The bottom line is, the irreducible complexity of some of life's most basic systems has never been explained by evolutionists, despite the challenge to do so being published over 10 years ago."
Yes, it has been answered. And with each answer the ID/creation crowd runs off with it's tail tucked between it's legs to find the next sure fire, silver bullet irreducibly complex structure that they're sure will topple the evil Evolution Conspiracy once and for all. It hasn't, and will not, work since evolution quite readily explains such things.
"Until a plausible and scientifically valid explanation can be provided, I think we must consider and teach alternative explanations."
Fine. Give a scientifically valid alternative explanation.
"Science only gets better and more robust through exploring alternate explanations for observed phenomenon, not by silencing dissent."
Agreed. Which is why scientific journals and various gatherings of scientists from around the world happen.
