Researchers have developed a technique to speed evolution by inserting human cancer-causing genes into animals and plants.
Hundreds of mutant breeds - which would normally take nature millennia to produce - could be developed in months by the method, known as hypermutability.
But the technique - designed to improve production of new animal and crop breeds - has shocked many scientists and environmentalists. Some say the process could result in organisms with human cancer-causing genes being released into the environment. Others worry that attempts to accelerate evolution could be dangerous.
However, its creator, the US-based company Morphotek, says it could be valuable to drug and agriculture companies, making it possible to isolate highly profitable breeds, drought-resistant plants or milk-rich cows.