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Factors increasing variation
Darwin
would be delighted to know what we now know about the extent of variation
in populations. Scientist now believe that the following factors increase
variation:
- Mutations:
Genetic mistakes in DNA occur often during gamete formation. If
DNA is changed, the resulting proteins change and traits never before seen
in a species will appear.
- Genetic Recombination:
When gametes (sperm & eggs) are produced by meiosis, only half
of the parents' genetic material is packed into them. When they unite
to form a zygote (1st cell of the new individual) the result is not exactly
like either parent. Each sexually produced offspring is unique and
has variation combinations not present in any other individual of that species.
- Migration:
Genes can flow into or out of a population from individuals of that
species coming from a different environment. Often, new traits will
be injected into the population.
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