As part of the evolution unit in AP biology.  I asked my students to read an excerpt from Bill Bryson’s "A Short History of Nearly Everything" on evolution and Charles Darwin.  They had to respond to a variety of topics on our Class Google Group. 

One student posted that she was surprised that Darwin spent so many years on his barnacle study.  After all, barnacles are boring, no?

Familiar with an interesting quirk of barnacle anatomy, I couldn’t help but respond by quoting the above-linked excerpt from the Wikipedia page on barnacles:

The sessile lifestyle of barnacles makes sexual reproduction difficult, as the organisms cannot leave their shells to mate. To facilitate genetic transfer between isolated individuals, barnacles have extraordinarily long penises. Barnacles have the largest penis to body size ratio of the animal kingdom.^[13]