Eggshells reveal birds’ evolutionary secrets

Molecules from eggshells of endangered and extinct birds can tell behaviour and evolutionary history of Australian feathered fauna, reveals a study.

James Haile from Murdoch University, who pioneered the breakthrough technique, said eggshell has been largely overlooked as a source of information, despite its impermeability and resistance to decay, owing largely to the calcium carbonate matrix which acts to protect biomolecules.

Haile says researchers take the eggs of extinct and endangered birds and grind them down before sequencing the DNA to learn new information about these birds.

“For extinct birds, such as Madagascar’s elephant bird, we extract the DNA and compare that to living birds such as emu, cassowary, ostrich and others — from that we can see how those birds fit into the broader family tree and at what point they diverged,” said Haile, according to a university statement.

“For the endangered birds, we take samples of abandoned eggshells and together with DNA samples from chicks and captive birds develop a population database to get a picture of genetic diversity of the population,” he said.

The application of my research can help to identify smuggled eggs coming into Australia and learn more about the behavior of Australia’s endangered birds for conservation strategies, said Haile.

It could even help determine the precise timing of the fragmentation of the supercontinent Gondwana, he said.

“Elephant bird eggs are the largest ever known, bigger than any dinosaur egg, and very resistant to decay. So they’re an ideal but under research source of DNA,” he added.