Microevolution

Microevolution is an observable change in frequency of the occurrence of certain traits within a population. An example of this is the antibiotic resistance seen in newer bacterial strains. Recent study shows that more babies are being born without wisdom tooth and an extra artery. There are 4 ways in which this can occur.

1. Mutation : Mutations are change in DNA caused by radiation, viruses, chemicals and/or errors that occur during DNA replication.
2. Selection : This process leads to the selection of heritable traits(traits that are passed on to generations) that can aid reproduction and increases the chance of survival within a population.
3. Genetic Drift : If the presence of a trait in an offspring is based on chance, then over time the genetic composition in a population can drift either way. This can lead to a noticeable change in the composition of a particular trait within a population.
4. Gene Flow : This includes exchange of genes between populations usually of the same species. Exchange during migration and then breeding or the exchange of pollen are examples of gene flow.