National Geographic's Article titled, " "Shrunken" Boas Pose Question: Nature or Nurture?" follows Auburn University herpetology graduate student Scott Boback and his research on boa constrictors and their size differences between the mainland and islands off the coast of Belize. His work resembles that of Charles Darwin and his studies of differing traits in birds on seperate islands. It raises the question of the effects of nature vs nurture.
Relating it to Boback's study of the boas, Darwin wanted to see how the environments on different islands affected the evolutionary development to better their ability to find food. In the case of the birds, it was their beak size that changed depending on the type of seeds that were most commonly found on the islands. For the snakes, it is a similar situation. On the mainland, there are bigger snakes due to the fact that they hunt mostly mammals and other reptiles of a bigger size. But on the islands, they hunt mostly small birds, so they are smaller in size - either because they don't get as many nutrients to grow, or because it is advantageous for them to be smaller (speed, hiding, etc).
This article was written at the beginning of his research (in 2003), and it left a lot of questions to be asked. Boback also stated that in some cases, the snakes would be even larger on certain islands. So it makes me wonder if there are other factors that can sometimes weigh more heavily? Like, would the snakes grow larger if there were simply fewer snakes on the island, and therefore more food available? And would that lead to more and more snakes, eventually making them smaller due to lack of food? And what about physical living situations? Or weather/climates?
So, in my opinion, it is a very interesting study that I'd like to read more about once more extensive research has been done.