Holding up well after all these years
Bones keep their DNA down a tropical sinkhole.
US scientists have reported recovering the first genetic data from an extinct bird in the Caribbean, thanks to some remarkably preserved 2500-year-old bones found more than 30 metres down a flooded sinkhole.
Studying ancient tropical birds is notoriously tricky because organic material degrades quickly when exposed to heat, light and oxygen, and the birds have light, hollow bones that break easily.
But the dark, oxygen-free depths of Sawmill Sink, on Great Abaco Island, provided ideal conditions for preserving the bones and DNA of Caracara creightoni, a large carrion-eating falcon that disappeared soon after humans arrived in the Bahamas about 1000 years ago.
Jessica Oswald from Florida Museum of Natural History admits to having modest expectations when she set to work on the femur, but it yielded 98.7% of the bird's mitochondrial genome.
"I was super excited. I would have been happy to get that amount of coverage from a fresh specimen," she says. "Getting DNA from an extinct bird in the tropics is significant because it hasn't been successful in many cases or even tried."