It’s natural to be nervous about this. CRISPR is a powerful tool that scientists don’t fully understand, and it can have unintended consequences even when used cautiously. Ever since April, when a team of Chinese researchers published their findings after using CRISPR to change the genes of human embryos, the discussion has reached a fever pitch. Experts have been discussing the issue of consent (embryos can’t consent to having their genes manipulated, and the effects could be passed down for generations), the consequences of introducing an unintended change, and the effects on the ecosystem should a genetically manipulated animal break free from the lab.