Handy Genes? inhumane research

I just couldn't believe the type of experimentation these scientists were engaged in. The genetic-altering configurations of the shark embryos were an inhumane act. The embryos were mutated just to understand the development of the hand or fin. I never knew a hand develops from one side of the hand to the other and that is why we have a thumb and pinky that are shaped differently. I never knew the ZPA if duplicated could mirror the hand/fin and make it double. Although this information was discovered, the way professionals experimented was inhumane and cruel. Hopefully, the book doesn't discuss anymore experimentations/mutations of animals or their embryos. :(