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