After 4,000 years of extinction, the woolly mammoth could soon walk the earth again, as scientists reveal the huge beast could be resurrected within two years.

Scientists believe they will have the technology to create an elephant and mammoth hybrid embryo through groundbreaking genetic engineering, by programming mammoth genes into an Asian elephant.

In comments ahead of the American Association for the Advancement of Science (AAAS) annual meeting in Boston (16 to 20 February) experts discussed the so-called "de-extinction" effort.

"Our aim is to produce a hybrid elephant-mammoth embryo," said Prof George Church according to the Guardian newspaper.

"Actually, it would be more like an elephant with a number of mammoth traits. We're not there yet, but it could happen in a couple of years."

The technique scientists hope to utilise is a gene-editing tool known as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9).

The revolutionary tool can be programmed to identify, cut and/or replace any gene sequence. Scientists in China have previously claimed CRISPR can be used to genetically engineer cows to have a heightened resistance to tuberculosis.

The system is considered much easier to use than earlier gene editing tools, meaning the breakthrough has huge implications for genetic research. The proposed resurrection of the animal, sometimes referred to as a 'mammophant', is led by the Harvard team which has outlined a two-year deadline.

First experts plan to create an embryo with features of a mammoth, such as shaggy long hair, thick layers of fat, and cold-adapted blood which would be combined with the DNA of an elephant.

Then, it is hoped, the embryo could be potentially used to bring the mammophant back to life inside an artificial womb.

Woolly mammoths
The woolly mammoth died out around 4,000 years agoiStock

Professor George Church, who heads the Harvard University team, said: "We're working on ways to evaluate the impact of all these edits and basically trying to establish embryogenesis in the lab.

"The list of edits affects things that contribute to the success of elephants in cold environments.

"We already know about ones to do with small ears, sub-cutaneous fat, hair and blood, but there are others that seem to be positively selected."