In order for a scientist in genetic engineering to end sufferings from children and adults they would have to continuously breed out the non-desired trait. Meaning this would take many years of a long and tedious process. In other words if you wanted the odds at 0.01 you would need to breed the trait out through 90 generations. To have a one in one million chance it would take 900 generations. That is not the desired time the scientist were hoping for as well as the population. This book is 136 pages so i did only give an exert from a paragraph that really stuck out to me.