Leading scientists have called for a ban on research to “re-engineer the human species” for the next five years.
Two babies were born last year in China who had been genetically altered to protect them against HIV.
The scientists, writing in the journal Nature, said “major speed bumps” needed to be put in front of such research.
The US National Institutes of Health said a ban should start immediately, but others have criticised the idea.
How do you re-engineer the human species?
It all comes down to the ability of scientists to manipulate DNA.
Our DNA contains the instructions for building and running the human body including traits such as height, hair colour and risk of diseases.
A relatively new tool called CRISPR has allowed scientists to quickly