Don't get too upset! Although it is not *completely* a joke, it is also not exclusive just to Puerto Ricans. If you live on an insular island, you're in the game! And, yes, I grew up on and island about the size of Puerto Rico, as well. What I am referring to is an interesting concept called "Morphologically Accelerated Evolution" or the "Island Effect".

Quite a mouthful, but really just meaning a speed up of evolution. Evolution, for those of you not familiar with Darwin by now, in its simplest form is just a "change in a species". All species evolve over time, some slower than others, and some very fast (strains of bacteria, etc).

Basically the Island Effect has shown that more rapid evolution occurs the more isolated and small an island is. Not only that, but also mammals that are small tend to grow larger, and mammals that are large tend to grow smaller.

Among insular mammals, there is a general tendency for small mammals to evolve toward larger size and larger species to evolve toward smaller size. This tendency has come to be known as the island rule. For example, the trend of increased body size ("gigantism") has been documented in numerous rodent taxa on islands. On the other hand, dwarf mammoths, elephants, hippopotami, and deer are classic cases of island evolution in the field of vertebrate palaeontology.

So I guess it's possible in a few hundred years we'll have 20 lb. coquis and Puerto Ricans small enough to be cast directly into the next installment of Lord of the Rings movie franchise, without any special effects. Gulliver will be really surprised when his boat comes ashore.

For those of you interested in Science, here is an article discussing the Island Rule.

The Insider