Such throwbacks even occur in human infants. (dinosaur factory)Hospitals occasionally register an entirely modern-looking baby characterized by all the expected organs, plus an unexpected tail, a long, caudal appendage protruding beyond the buttocks for two or three inches. Some of these tails are even bigger than the average caudal remnant displayed by our close kin, the chimps, gorillas, and orangutans.
Genetic experiments have revealed that these throwbacks are controlled by suppressor genes. (dinosaur costume)We now know that most complex pieces of anatomy – such as the clavicle and its muscles are controlled directly and indirectly by scores of genes that interact and can suppress each other. We also know that the full genetic blue-print in any single species is rarely, if ever, fully expressed. Instead, much of the genetic information is stored in the “inactive file,” genes that don’t produce their potential impact because some other gene prevents them from turning on. (animatronic dinosaur manufacturers)When an anatomical feature disappears during evolution, its genetic blueprint is not erased. Some new combination of genes has evolved to suppress the still-present blueprint.
Birds with teeth may have appeared ridiculous to creationists, but in point of fact modern birds do carry the ancestral genetic code for making teeth tucked away in their inactive file. No living species of bird manufactures teeth. But recent surgical manipulations of bird embryos demonstrate clearly that the potential is still there. In 1983, experimenters transplanted tissue from the inner jaw (dental lamina) of an unhatched chick to an area of the body tissue, where the graft could grow. In the transplanted position, the chick’s dental lamina started to produce tooth buds! Birds with teeth could grow right in the twentieth century.