Moa bones offer climate clues
ANALYSING the DNA in moa bones may hold the key to answering questions about what will happen to other New Zealand species when they attempt to adapt to climate change today and in the future.
University of Otago zoology researchers have analysed DNA of the extinct eastern moa, and discovered the giant birds altered their distribution around New Zealand as the climate warmed and cooled.
Lead author Dr Alex Verry said the species was spread across the eastern and southern South Island during the warmer Holocene period, but was restricted to the southern South Island during the height of the last Ice Age about 25,000 years ago.
By comparison, the heavyfooted moa retreated to both southern and northern regions of the South Island, while the upland moa inhabited four different areas.
‘‘The eastern moa’s response [to temperature change] had consequences for its population size and genetic diversity.
‘‘The last Ice Age led to a pronounced genetic bottleneck which meant it ended up with lower genetic diversity than other moa living in the same areas.’’
Dr Verry said it was the first time high throughput DNA sequencing, which simultaneously sequences millions of pieces of DNA, had been used to investigate moa at the population level.
The findings highlighted how past climate change had impacted species in different ways, and that a ‘‘onesizefitsall’’ model was not practical.
‘‘It makes us wonder what is going to happen to species as they attempt to adapt to climate change today and into the future.
‘‘Will they also attempt to move to new areas in order to survive?
‘‘For some species, this will not be possible. Some species will run out of space, such as alpine species which will have to move upward but can only go so far until there is no more ‘up’.’’
Coauthor Dr Nic Rawlence said the research was a rare example of the impacts of past climate change on extinct megafauna from New Zealand.
It also demonstrated how fossil remains and museum collections could be used to answer new questions about the past.
‘‘This is really bringing the power of palaeogenomics to New Zealand research questions, whereas previously most research and interest has focused on Eurasian or American species.
‘‘We are really starting to build capacity for this research in New Zealand,’’ he said.