7 Apr 2019

Why the kiwi and moa stopped flying

From Sunday Morning, 11:33 am on 7 April 2019

Researchers have found out what made two of our famous birds flightless. 

It's made it into the journal Science, this research into the genomes of eight flightless birds, including our kiwi and moa. 

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Photo: supplied

They suggest the loss of ability to fly came from non-coding DNA that regulates protein genes, rather than from the protein-coding genes themselves. 

Dr Paul Gardener at Otago University is one of the authors of the study and explained to Jim Mora what this all means. 

“Traditionally we think of proteins as being the engines of the cell, they carry out many of the important functions within the cell. When we look for big changes in species we really expect to see parallel changes in the proteins. What some of our tools showed is that those changes weren’t happening in the proteins but actually in the non-coding regions around the proteins.”

It’s about how the software operates, rather than the hardware, he says.

While they’ve found out what made them flightless, we are still no closer to finding out exactly why this happened.

“We’re still very much in the early days of figuring out what all of the information in the genome meaning.”

Evolution doesn’t plan particularly well, says Gardener.

“These weird sort of cludges or weird solutions to problems are what we typically see in genetics. It’s more of a fine-tuning or tweaking of the system rather than something decided they didn’t need to fly anymore and it went and flicked a whole bunch of switches.”

Not flying was clearly an advantage for these species, he says.

For the moa, in particular, becoming much larger meant they weren’t going to get eaten by some of the smaller species anymore.

“If you are big and strong, actually flying is not that useful of a thing to have.”

And, he says, it’s possible in the future that’d even be able to revert some of these changes, without knowing what the consequences would be.

“Would we really get a flying kiwi? Probably not but we might get some interesting changes between the kiwi if we reverted some of these switches back the ancestral state.”

With New Zealand’s regulations on genetics, however, it wouldn’t be possible to do on our shores, he says.