Oops, a tiny misspelling there. Should read “designer genes” or, as they’re frequently called today, “epigenes.” Conrad Waddington is said to have introduced the idea of epigenes, which, according to MedlinePlus are control genes that modify (typically turn on or off) other genes without affecting the organism’s DNA. In other words, epigenes are genes that regulate the activity (expression) of DNA. Epigenes themselves can be affected by time, as well as intracellular or external c...