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Melbourne scientists solve mystery of emu’s tiny wings and wonder if same gene can fix human limb defects

Grant McArthur, July 27, 2017 8:57AM Herald Sun

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Three-week-old emu chick. Picture: Toby Zerna media_cameraThree-week-old emu chick. Picture: Toby Zerna


Reading level: red

THE same tiny and useless wings that have kept emus’ feet planted firmly on the ground are now sending scientists into a flap over their implications* for human limb* development.

Melbourne researchers have unlocked the secret of why the large, flightless emus have evolved tiny wings.

With this new knowledge, they believe they could now reverse evolutionary change to give Australia’s national emblem larger wings to match its body size.

The discovery of the gene responsible for limiting the size of an emu’s wings has also raised the prospect for Monash University and Murdoch Children’s Research Institute scientists to see if the same process plays a part in the development of human deformities, which could also be reversed.

A large emu. Picture: Chris Pavlich media_cameraA large emu. Picture: Chris Pavlich

Genes are passed down from parents to their offspring and they control much of what their descendants look like.

After working out the genes that control the early stages of wing development in both emus and chickens, the researchers discovered one only present in the underdeveloped wings of the bigger, flightless emu.

Monash Assoc Prof Craig Smith said that the discovery of the gene they call Nkx2.5 limited the growth of emu wings to 20cm in size. They already knew it was a cause of heart defects in humans and animals.

Dr Peter Farlie then inserted the emu gene into growing chicken embryos and the chicks also grew tiny emu-like wings, confirming the gene’s role in limiting size.

An emu in Queensland. Picture: Claudia Baxter media_cameraAn emu in Queensland. Picture: Claudia Baxter

The next stage of research will see Assoc Prof Smith undertake “genetic rescue” by removing the target Nkx2.5 gene in growing emu embryos so they are born with larger wings, though they still won’t be flying.

“We do want to delete the gene in the emu and see whether we can restore* a normal wing,” Assoc Prof Smith said.

“It would have big wings, but it wouldn’t be able to fly because they are a large bird that could not get off the ground.”

The genetic discovery raises hope for overcoming human deformities.

The Nkx2.5 gene affects heart development and can be found mutated in children born with heart defects. It is now suspected of playing a part in human limb development.

Bright blue emu eggs and an emu chick. Picture: Glenn Ferguson media_cameraBright blue emu eggs and an emu chick. Picture: Glenn Ferguson

“This gene is normally turned on in the heart in mammals and humans … so it is certainly feasible* that abnormal activation of this gene could potentially lead to limb abnormalities in humans,” Assoc Prof Smith said.

If they can figure out the role the gene plays in the development of human arms and legs, doctors and scientists could potentially fix any developmental* problems in babies before they are born.


implications: results

limb: legs and arms

restore : bring back

feasible: possible

developmental: in the development stage



Activity 1. In short…

There is lots of interesting information in this article and some of it is quite complicated.
If you wanted to tell somebody else about the article you probably wouldn’t be able to remember all of the details.
You would need to remember just the main points in the article.

Write down five dot points that you feel capture the gist of the news story.


Referring back to just the five dot points you recorded for reminders, see if you can verbally retell the news story to a partner.

Time: allow 20 minutes to complete this activity

Curriculum links: English

Activity 2. Evolution

Research and write a basic definition in your own words for the term evolution.

The article gives an example of emus who have evolved smaller wings over time.
Find and record three more examples of ways other species have evolved.


Think about the way humans have lived in the past, how we live now and how we may live in the future.
Draw a picture of a future human showing three characteristics that you think may change over time as the human species evolves.

Write a short explanation for each of the changes you predict.

Time: allow 30 minutes to complete this activity
Curriculum links: English, Science


(Vocabulary, Connectives, Openers, Punctuation)

Compare and Contrast

Choose a glossary term and list as many synonyms as possible.
Then choose two synonyms and compare and contrast each word.
Although they are similar, synonyms can often be subtly or vastly different.

For example: fun
Synonyms: enjoyment and amusement

Enjoyment is a feeling you experience when you like something and amusement is when you like something but also find it funny.

Time: allow 15 minutes to complete this activity

Curriculum links: English, Big Write, VCOP







Extra Reading in science