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Variation and evolution GapFill
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is a term used widely in biology to describe the amount of difference seen between organisms of either the same or different species. This can be due to genes, or a combination of both. Within a population of a single species, there is normally genetic variation, and this can often lead to the basis of evolution.
According to the theory of evolution, when an organism develops a useful trait, as a result of , that trait is inherited. The trait then becomes more common in the population, as those without it are at a disadvantage.The principle of inheritance can be used in selective breeding. This is used so that humans can develop the most useful organisms for their needs. During this process, humans identify an organism with a valuable trait, such as a plant with large flowers or domestic dogs with a gentle nature. However, extensive selective breeding can lead to , which can put the organism at risk of genetic disease.
A more complex way that humans can make the most of their valuable species is by , where genes are inserted into the nuclei of developing organisms. Plant crops have been engineered to be resistant to some diseases or to produce bigger fruits. Crops that have undergone this technique are called , and there are many concerns about the effects of these organisms on humans and ecosystems.