Abstractions

摘要

In the birth defect phocomelia, the long bones of the limbs are shorter than normal or, in the worst cases, do not develop at all, meaning that the hand or foot is attached directly to the shoulder or hip. Scientists studying the disorder - also seen in the 1950s and 1960s in the children of women who were prescribed the sedative thalidomide while pregnant - can mimic its characteristics by exposing the limb buds of developing chick embryos to irradiation.