From the University of Adelaide:

DNA recovered from fossilized bones of the moa, a giant extinct

bird, has revealed a new geological history of New Zealand, reports a

study published this week in the Proceedings of the National Academy of Sciences.

A

team of scientists led by the University of Adelaide has reconstructed

a history of marine barriers, mountain building and glacial cycles in

New Zealand over millions of years, using the first complete genetic

history of the moa.

(Image: Giant Haast's eagle attacking moa; Credit: John Megahan)

After almost being totally submerged around

25 million years ago, the current South and North Islands were

separated by a large sea until around 1.5 million years ago,

researchers say.

Project leader Professor Alan Cooper from the

University of Adelaide’s Australian Centre for Ancient DNA (ACAD) says

New Zealand is recognized as one of the world’s “great evolutionary

laboratories” due to the absence of land mammals and the radiation of

giant flightless birds such as the moa. “Yet this research is rewriting

the geological history of New Zealand and shows how little we really

know about it,” Professor Cooper says.

The team of Australian and

New Zealand researchers sequenced DNA from hundreds of birds collected

from caves and swamps, including all nine species of moa. The birds,

which weighed up to 250kg, were the dominant animals in New Zealand’s

pre-human environment but were quickly exterminated after the arrival

of the Maori around 1280AD.

“We found that the remarkable

evolutionary dispersion of the nine moa species took place in only

seven million years and seems to have occurred as the Southern Alps

rapidly rose up and created lots of new habitats,” Professor Cooper

says. The evidence also suggests that many of New Zealand’s iconic

species – including the kiwi, tuatara and kauri – evolved solely on the

South Island.

“This raises the question of what was happening on the North Island during this time?” Professor Cooper says.

Lead

author Dr Mike Bunce from Murdoch University extracted traces of DNA

from moa bones, mummies and coprolites, which the researchers were able

to use to create the first detailed evolutionary time frame for moa.

Professor

Peter Kamp from Waikato University led the geological mapping that

revealed the extent of the seaway separating the two islands, as well

as the uplift history of the Southern Alps.

“When the seaway was

first bridged by land around 1.5 million years ago, it is likely that a

major interchange of species took place as also occurred between North

and South America across the Panama isthmus around three million years

ago,” Professor Kamp says.

Team member Dr Trevor Worthy from the

University of NSW said the study was “an excellent example of how

museum specimens can contribute to cutting-edge science”.