In nature genetic diversity is created within certain limits. For example, a rose can be crossed with a different kind of rose but not with a potato. Genetic engineering on the other hand usually involves taking genes from one species and inserting them into another different species in an attempt to transfer a desired trait or character. An example of this would be selecting a gene which expresses antifreeze characteristics from an artic fish (such as a flounder) and splicing it into a potato or strawberry to create frost resistance. It is now possible for plants to be engineered with genes taken from bacteria, viruses, animals, or even humans.