Who would have thought that a tomato could possess characteristics of a fish? What about a plant possessing characteristics of a firefly; or a pig with human traits? These things may sound like science experiments gone wrong, but in truth, these are products of experiments that went well. The fish-like tomato and others are results of genetic modification or genetic manipulation, which are more commonly known as genetic engineering. Genetic engineering is the process of taking genes and segments of DNA from one species and putting them into another species, thus breaking the species barrier and artificially modifying the DNA of various species. These changes in DNA result in an alteration of reproductive and hereditary processes of the organisms since the process is irreversible and the organism's offspring will also possess this unique DNA (Levine).