Long before TV's campy Fantasy Island, the isolation of island communities has touched an exotic and magical core in us. Darwin's fascination with the Galapagos island chain and the evolution of its plant and animal life is just one example.
Think of the extensive lore surrounding island-bred creatures like Komodo dragons, dwarf elephants, and Hobbit-sized humans. Conventional wisdom has it that they -- and a horde of monster-sized insects -- are all products of island evolution.
But are they?
Dr. Shai Meiri of Tel Aviv University's Department of Zoology says "yes," they are a product of evolution, but nothing more than one would expect to see by "chance," citing research that shows there's nothing extraordinary about evolutionary processes on islands. He and his colleagues have conducted a number of scientific studies comparing evolutionary patterns of island and mainland ecosystems, and the results refute the idea that islands operate under different, "magical" rules.
Man bites evolutionary dog
"My findings are a bit controversial for some evolutionary biologists," says Dr. Meiri, the author of several papers and essays on island evolution. His research is based on statistical models he developed.
"There is a tendency to believe that big animals become very small on islands, and small animals become very big, due to limited resources or lack of competition. I've shown that this is just not true, at least not as a general rule. Evolution operates on islands no differently than anywhere else."
In a recent study reported in Global Ecology and Biogeography, Dr. Meiri and his colleagues looked at a theoretical optimum body size towards which mammals are expected to grow, on both island communities and on the mainland. Contemporary evolutionary thinking maintains that smaller island mammals will rapidly grow larger towards the optimal size, while bigger animals will rapidly shri
|Contact: George Hunka|
American Friends of Tel Aviv University