Why do we cease to teach through the medium of verse? In children we happily sing songs and tell stories to convey moral tales and even astronomy, math, and economics.
We know how effective this is in teaching young children ("My Very Evil Mother Just Swatted Uncle's Nose" -- for the planets) and yet why not teach the theory of evolution in metre and rhyme?
Great poets, in fact, do teach in this manner. In this very simple ballad, Wordsworth conveys a complex theoretical proposition from Erasmus Darwin's Zoonomia: The Laws of Organic Life."