Moa DNA gives up some secrets

BREAKTHROUGH: An image of moa eggshell DNA which New Zealand and Australian researchers are studying.

VALUABLE ARTIFACT: Fossil moa eggshell is providing new DNA evidence about the birds.

Relevant offers

A breakthrough in DNA extraction will enable researchers to understand the family life of moa and pinpoint when they became extinct.

A team of researchers on both sides of the Tasman has managed to isolate ancient moa DNA (deoxyribonucleic acid) from fossil eggshell gathered around New Zealand. Its findings were published yesterday in the Royal Society's Proceedings B journal of biological sciences.

Lead author Charlotte Oskam, an Otago MSc graduate now studying for her doctorate at Perth's Murdoch University, said previous attempts to recover DNA from fossil eggshell had been unsuccessful.

Co-authors include Otago University archaeologists Chris Jacomb and Richard Walter and Canterbury University palaeobiologist Richard Holdaway.

Jacomb told The Press the DNA extraction would enable scientists for the first time to match eggshells to specific moa species, of which there were now believed to be about nine.

"Every couple of years there's a new breakthrough with moa research," he said. "The interesting thing from the bird eggs is they seem to preserve the eggshell DNA and biomolecules better than bone because of the crystalline structure of the eggshell itself."

He said Oskam and Murdoch University researchers had managed to extract from the shells mitochondrial DNA – inherited only from the mother – and nuclear DNA – inherited from both parents.

"Mitochondrial DNA doesn't change rapidly but nuclear DNA gets mixed up and recombines with each generation, so each individual offspring has its own unique nuclear DNA," he said.

"Extracting both are both breakthroughs. It means we can study moa at a population level rather than as a regional presence, and it can tell us things about where the moa being hunted and laying eggs were living, so we can tell if they were in valley floors or hilltops."

Research had shown that moa were extinct between 50 and 150 years after Polynesian settlement of New Zealand, which was about 1280 to 1300, Jacomb said.

"One spinoff of the study will be the production of more than 100 radiocarbon data on eggshells of moa. That will provide a much better line of evidence for the time of extinction," he said.

Eggshell fragments were collected from Redcliffs in Christchurch, Pounawea in the Catlins and Hawke's Bay.

- © Fairfax NZ News