The gene gun was invented in 1987, allowing transformation of plants not susceptible to Agrobacterium infection.  The term GMO originally was not typically used by scientists to describe genetically engineered organisms until after usage of GMO became common in popular media. , A narrower definition provided by the Food and Agriculture Organization, the World Health Organization and the European Commission says that the organisms must be altered in a way that does "not occur naturally by mating and/or natural recombination". Rev.  Other ways to test a gene is to alter it slightly and then return it to the plant and see if it still has the same effect on phenotype. , There is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, but that each GM food needs to be tested on a case-by-case basis before introduction. However, new technologies are making genetic modifications easier and more precise. GMOs are organisms that have had their characteristics changed through the modification of their DNA. This included genes from the toad Xenopus laevis in 1974, creating the first GMO expressing a gene from an organism of a different kingdom. , It has been proposed to genetically modify some plant species threatened by extinction to be resistant to invasive plants and diseases, such as the emerald ash borer in North American and the fungal disease, Ceratocystis platani, in European plane trees. A genetically modified organism (GMO) is an organism whose DNA has been modified in the laboratory in order to favour the expression of desired physiological traits or …  A GM chicken that produces the drug Kanuma, an enzyme that treats a rare condition, in its egg passed US regulatory approval in 2015. This process is called transduction and if successful the recipient of the introduced DNA becomes a GMO. Different viruses have different efficiencies and capabilities.  Scientists can easily manipulate and combine genes within the bacteria to create novel or disrupted proteins and observe the effect this has on various molecular systems. , Humans have domesticated plants and animals since around 12,000 BCE, using selective breeding or artificial selection (as contrasted with natural selection).  Approval is for fish raised in Panama and sold in the US. , Mammals are the best models for human disease, making genetic engineered ones vital to the discovery and development of cures and treatments for many serious diseases. , Genetically modified organisms are regulated by government agencies.  In 2009, scientists announced that they had successfully transferred a gene into a primate species (marmosets) for the first time. The development of the CRISPR-Cas9 gene editing system as a cheap and fast way of directly modifying germ cells, effectively halving the amount of time needed to develop genetically modified mammals. Herbert Boyer and Stanley Cohen made the first genetically modified organism in 1973, a bacteria resistant to the antibiotic kanamycin. , Their ease of use has made them great tools for scientists looking to study gene function and evolution. , The process of genetically engineering mammals is slow, tedious, and expensive.  Genes associated with the woolly mammoth have been added to the genome of an African Elephant, although the lead researcher says he has no intention of creating live elephants and transferring all the genes and reversing years of genetic evolution is a long way from being feasible. Genetically modified (GM) organisms are organisms that have had their genomes changed in a way that does not happen naturally.  DNA is generally inserted into animal cells using microinjection, where it can be injected through the cell's nuclear envelope directly into the nucleus, or through the use of viral vectors.