Please read this short news article: https://singularityhub.com/2022/09/11/scientists-use-crispr-to-condense-a-million-years-of-evolution-into-mere-months/ Although not required, if you are interested you can download the actual scientific study here. My summary of the content: Mice have 20 pairs of chromosomes in every cell. Gain or loss of one or more chromosomes (called “aneuploidy”) is usually incompatible with life. Using CRISPR, scientists fused mouse chromosomes 4 and 5 together and created mice with 19 chromosomes. Surprisingly, these mice had seemingly normal behavior and bodies and gave birth to pups that also lacked a pair of chromosomes. My questions are: If mice are “normal” with 19 pairs of chromosomes, why did they evolve to have 20? Perhaps they will evolve to have 19 chromosomes in the future but should we hasten evolution? What are your thoughts on this?