Darwin Today @ NMNH
Meet Dr. Helen James
Helen James, PhD, is a curator of birds. She studies ecological collapse in islands after human occupation and adaptive radiation in Hawaiian finches.
I was in a lava cave on Maui collecting bones of extinct flightless birds that had fallen into the cave hundreds of years ago. Their skeletons littered the cave floor. The strangest bird was a turkey-sized goose with a heavy body, stout legs, a deep bill with bony pseudo-teeth, and tiny wings.
Suddenly, we spotted a bone that made us change our thinking about this strange bird. The bone was a specialized structure that forms only in the windpipes of male ducks, not in true geese. When we obtained ancient DNA sequences from the fossils, we confirmed that these large, land-dwelling, flightless birds of Maui had evolved from a duck-like ancestor. After traversing the Pacific Ocean to Hawaii, the ancestral species had undergone a dramatic evolutionary adaptation to island life that included changes in diet, habitat, body size, and body form.Darwin used observations about comparative anatomy, the fossil record, and the special animals that live on islands to support his theory about the origin of species. Our research on the flightless duck used the same general approach with the advantage of modern knowledge and technology. The flightless duck illustrates how Charles Darwin’s ideas explain not only his own observations but also the biological data that have been gathered since he published On the Origin of Species 150 years ago.
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