Alligators hint at what life may have been like for dinosaurs
During the last 540 million years, the earth's oxygen levels have fluctuated wildly. Knowing that the dinosaurs appeared around the time when oxygen levels were at their lowest at 12%, Tomasz Owerkowicz, Ruth Elsey and James Hicks wondered how these monsters coped at such low oxygen levels. But without a ready supply of dinosaurs to test their ideas on, Owerkowicz and Hicks turned to a modern relative: the alligator. 'We knew testing the effects of different oxygen levels would work with alligators,' Owerkowicz explains, 'because crocodilians have survived in their basic shape and form for 220 million years. They must be doing something right to have survived the oxygen fluctuations.' Choosing to start at the beginning of alligator development, the trio decided to try incubating alligator eggs at different oxygen levels, to find out how the youngsters grew and developed and publish their results on April 17 2009 in The Journal of Experimental Biology at http://jeb.biologists.org.