Mutaciones

1- Mutations

Mutations are changes in the DNA sequence, these sequence changes are sudden and spontaneous variances in the cell.

If the mutated phenotype is favorable, the organism will survive and be able to reproduce.

Mutations are sometimes very lethal to the cell they are found in, and will not always be advantageous to the organism.

Types of mutation:

• Sustitution

A substitution is a mutation that exchanges one base for another.

• Insertion

Insertions are mutations in which extra base pairs are inserted into a new place in the DNA.

• Deletion

Deletions are mutations in which a section of DNA is lost, or deleted

• Inversion

In an inversion mutation, an entire section of DNA is reversed.

Is a mutation that causes a reversal in the order of a segment of a chromosome within the chromosome, or a gene.

2- Genetic Drift

In each generation, some individuals may, just by chance, leave behind a few more descendants (and genes) than other individuals. The genes of the next generation will be the genes of the “lucky” individuals, not necessarily the healthier or “better” individuals. That is genetic drift.

3- Genetic Flow

Is the transfer of alleles from one population to another, it is also known as migration. This is because certain animals are able to travel for long periods of time to far destinations, this causes reproduction with members of different populations. Plants are capable of this due to wind and bees as well, they transfer their pollen. Other examples are the mixture of races in our world today, war and exploration.

4- Non-random Mating

Mates are chosen on based on phenotype to ensure that a good set of genes is passed on to the next generations. Non- random mating implies that not all members of a population have and equal chance to leave offspring or mate.

5- Natural Selection

The process by which favorable traits become more common in successive generations, and unfavorable traits become less common. Organisms with unfavorable traits leave less organisms or die off, while those with the favorable trait survive and leave more offspring. Also known as survival of the fittest.

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