Microevolution
Microevolution is the change in allele frequencies brought about by mutation, genetic drift, gene
flow, and natural selection. Microevolutionary processes drive a population away from genetic
equilibrium.
Mutations are heritable changes in DNA that give rise to altered gene products.
Mutations have several characteristics:
- They are rare, chance events.
- Each gene has a characteristic mutation rate, based on probability of occurrence between or
during DNA replications.
Mutations can be of three types:
- Neutral mutations that neither help nor harm the individual
- Beneficial or advantageous mutations that enhance the prospects of surviving and reproducing
- Lethal mutations that always lead to death.
Mutations are the ultimate source of variation upon which natural selection depends.
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