Darwin didn't know that either, but neither did Clark.
That 5th dimension probably has a lot to do with genetics.
bttt. I will return to this when I finish my work.
Whether you are a Darwinist or a theist what Darwin said is extremely relevant. His views have permeated all of science, buisness, government, education, and popular culture. His views has it origins in the ancients like Demicritus and Epucurus, Lucretius, on up through Newton, Galileo, Bacon, Machiavelli, Hobbes, Locke, and right through the 1859 publication or Origins. AS it coupled with the ideas of Malthus, Nietzsche, Marxs, Hitler and the profundity of Darwins theory has issued in more pain and sufferiing than any other single idea.
Your tangential reference to string theory is, currently, irrelevant.
Well... it got me laid.