Are there specific genes for a big nose, high cheekbones or full lips? What — or who's — to blame for a widow's peak or wobbly jowl?

Key points: Dr Mark Barash has collected DNA from more than 1,300 Australians and is in the process of turning them into "molecular portraits"

Dr Mark Barash has collected DNA from more than 1,300 Australians and is in the process of turning them into "molecular portraits" He needs more volunteers to paint a full picture of the typical Australian face

He needs more volunteers to paint a full picture of the typical Australian face The science could one day help determine suspects by using DNA left at a crime scene, or help identify disaster victims

It's a question some of us might ask while grimacing at that appalling passport photo.

One researcher at the University of Technology Sydney (UTS) is looking to answer that by decoding the DNA that writes the recipe for the human face.

The research could also have important ramifications for solving crimes and unlocking the secrets of history.

Dr Mark Barash has collected DNA from more than 1,300 Australians and is in the process of turning them into "molecular portraits".

Using information already known, he's comparing what people look like with what their DNA says they should look like.

Reporter Jake Sturmer's DNA was analysed and compared with a 3D head scan. ( ABC News: Jake Sturmer )

But he needs more volunteers to paint a full picture of the typical Australian mug.

"Basically we're trying to see what are the genes behind our appearance," Dr Barash said.

"We already know how to predict a number of these traits such as eye, skin or hair colour [and] we know how to predict the biogeographic ancestry.

"Our facial appearance is extremely complex, we have such an enormous variety in facial appearance so we need a really big sample size to represent this variety.

"Diversity is key because we want to represent the multi-ethnic population in Australia."

Anything from what you eat, when you sleep, and how you exercise can all cause chemical modifications that can switch genes on or off over time.

This is known as epigenetics, and that's why Dr Barash needs a vast number of volunteers to track individual changes.

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DNA for solving crimes or identifying unknown soldiers

The science could one day help police identify perpetrators by using DNA left at a crime scene, or help when natural disasters strike and victims need to be identified.

"We look as things such as eyes, skin, hair colour, head texture, male baldness as well as facial appearance, facial traits," Dr Barash said.

"All these traits might be very useful to reduce the number of suspects, to make a shortlist of suspects."

The Australian Federal Police agree.

Dr Simon Walsh heads forensics as part of his role at the law enforcement agency.

All samples donated for the research are de-identified and kept secret. ( ABC News: Jake Sturmer )

"It really allows us to find out a range of information about an unknown source of evidence," Dr Walsh said.

"To literally produce the likely face of a donor from an unknown piece of DNA and to have come to that point is pretty incredible.

"Obviously it's going to have some significant implications in a positive way in terms of the work we do."

But, he said, the technology was not quite ready for day-to-day use.

"Part of that is because the inferences that come back from using the tests are still a little ambiguous," Dr Walsh added.

The technology could also be used by historians who could potentially take DNA from bone samples to paint a picture of ancient man or identify unknown soldiers.

"When the remains are highly degraded, we can introduce these normal molecular methods to produce information about the appearance of the person," Dr Barash said.

If you're keen to volunteer, all samples are de-identified and kept entirely secret.

But if you're unhappy with your dodgy DNA, there's really only one solution — plastic surgery.