Chinese scientist He Jiankui caused waves of controversy this week when he claimed to have made the world's first genetically edited babies. 

The associate professor at Southern University of Science and Technology in Shenzhen used a gene editing technology known as CRISPR-Cas9 to change the genes of embryos and implant them in the womb of a woman undergoing fertility treatment. He claims that he helped protect the twin girls, who were born last month, from being infected with HIV.

His claim has sparked a global debate about the ethics behind gene editing. Many Chinese scientists have denounced the claim, suggesting that any research on live human embryos is dangerous and unjustified. Others believed that his research process hasn't been transparent enough. 

However, many people forget that this is not the first gene editing story to have taken over headlines. Gene editing has come a long way since it was presented in 1991 by Pavletich and Pabo in the journal Science. In recent years the technology has developed at an astonishingly fast rate with new projects such as malaria resistant mosquitos, limitless supplies of transplant organs, and saving the world's coral reefs all down the pipeline.

So with this in mind, test out your knowledge of the significant breakthroughs of gene editing technology.