Can't observe and woefully hard to understand. Remember in the 1950's the only genetic disease they could trace to a mutation was sickle cell and that was guess

Can't observe and woefully hard to understand. Remember in the 1950's the only genetic disease they could trace to a mutation was sickle cell and that was guesswork. They didn't have any of the cute editing techniques or amplification and sequencing tools. It's a miracle they figured out what they did.