Changes

==Mutation==

==Mutation==

Changes of a species from its normal state are called [[mutation|mutations]]. Sometimes they happen on their own, but they can also happen when a parent is exposed to something that will affect the way they reproduce. High doses of [[X-rays]] can produce mutations, and so can some chemicals. According to [[Darwin’s theory of evolution|theory of evolution]], most mutations will be harmful, but some will help a member of a species to survive and will pass on to its offspring. Some mutations can be both helpful and harmful. For example, people from some [[Africa|African]] countries carry a gene for an illness called [[sickle-cell anemia]]. This illness causes health problems, but people who have the gene for sickle-cell anemia are also less likely to catch [[malaria]], a serious illness common in Africa.  

Changes of a species from its normal state are called [[mutation|mutations]]. Sometimes they happen on their own, but they can also happen when a parent is exposed to something that will affect the way they reproduce. High doses of [[X-rays]] can produce mutations, and so can some chemicals. According to the [[theory of evolution]], most mutations will be harmful, but some will help a member of a species to survive and will pass on to its offspring. Some mutations can be both helpful and harmful. For example, people from some [[Africa]]n countries carry a gene for an illness called [[sickle-cell anemia]]. This illness causes health problems, but people who have the gene for sickle-cell anemia are also less likely to catch [[malaria]], a serious illness common in Africa.

==References==

==References==