It’s claimed that the breakthrough could pave the way for altering DNA in the other direction and use the same process to create species better able to adapt to earth’s climate.

It could also help eliminating birth defects in humans, the researchers at the Harvard University said.

A team, led by evolutionary biologist Arkhat Abzhanov, changed the DNA of chicken embryos in the early stage of their development which enabled them to give the creatures snouts which are thought to have been lost in the cretaceous period millions of years ago, the Daily Mail reported.

For their research, the team cut a hole in the shell of a chicken egg and dropped in a small gelatinous protein bead before watching the embryo develop.

The changes allowed separate molecules on the side of the face free to grow into snouts within 14 days.

Though ethical regulations prevent the eggs from being hatched, Dr Abzhanov said he hopes to complete the work one day by turning chickens into Maniraptora-small dinosaurs believed to have spawned 10,000 species of birds. Chickens and other birds are thought to have descended from dinosaurs through a series of genetic changes.

Dr Abzhanov said they made the DNA changes by analysing the “signalling molecules” which control the anatomical changes in birds and other animals. Adding protein beads to the egg which stifle the development of certain molecules also prevented the birds from growing certain features, he said.

By altering the DNA of chickens to resemble alligator genes before the beak developed, the researchers were able to change the evolutionary path of chickens so that they grew snouts instead. “It looks exactly like a snout looks in an alligator [at this stage],” Dr Abzhanov was quoted as saying.

Craig Albertson, a biologist from the University of Massachusetts, said: “Abzhanov’s ‘snouted’ chicken provides a striking demonstration of just how easy it can be to provoke major evolutionary changes.”

Jack Horner, a leading paleontologist at the University of Montana, is conducting similar work in an attempt to make a “chickenosaurus” with a tail and hands like dinosaur.