Essay on the island rule

1 minute read

The web site for the Hobbit episode of Nova has opened. It let’s you e-mail questions for Mike Morwood, features some graphics with endocast scans and some video from the program.

The site also includes an essay by Peter Tyson on the history of the island rule, which is a nice article, even if you know a lot about island biogeography. Here’s a quote from the conclusion

Despite all the work in the three and a half decades since Foster first took an intellectual machete to the tangle of questions surrounding the gigantism/dwarfism question, much awaits illumination. As biologists James Brown and Mark Lomolino conclude in their classic textbook Biogeography, "the generality of the island rule and its corollaries ... remain promising areas for future studies."
New studies might also help clear up certain evolutionary conundrums. No one knows, for instance, whether the Seychelles giant tortoise became humungous before or after it arrived in the archipelago. No one knows why island-dwelling bears show only a slight degree of dwarfism despite their bearish build and carnivorous habits. And no one knows why ducks tend toward dwarfism. Many birds in evolutionary history have become gigantic (and flightless)the great auk, the ostrich, the elephant birds of Madagascar. Why has evolution never produced a giant flightless duck? "A question," muses [David] Quammen, "to lie awake over."

It would be a good essay for distribution to classes – a nice piece of work.

UPDATE (2008-11-8): A reader reminds me of the Demon Duck of Doom. D’oh – I should have remembered that one. He says, no sense lying awake at night over that one.