Mutations and Genetic Variants

A mutation is a random change in the genetic material of an organism.
Mutations can occur spontaneously or be induced by environmental factors like radiation or certain chemicals.
They can affect single DNA base pairs (point mutations) or larger segments of a chromosome.
Frameshift mutations are a type of point mutation caused by an insertion or deletion of bases. This disrupts the reading frame of the genetic code.

Mutations can be beneficial, neutral, or harmful depending on how they affect the organism’s survival and reproductive success.
Silent mutations do not change the amino acid sequence of the protein, as the altered codon still codes for the same amino acid - these are often neutral.
Nonsense mutations change a codon that originally coded for an amino acid into a stop codon, prematurely ending protein synthesis. These mutations are often harmful.
Missense mutations change one amino acid to another, potentially altering the function of the protein.

Genetic variants are versions of genes that differ from each other, due to mutations. A human can have many genetic variants which contribute to genetic diversity.
These genetic variants can lead to differences in visible traits, abilities, or susceptibility to diseases.
Genetic variants can exist in the same place (locus) on a chromosome, with each one being an allele. Having more than one allele at a certain locus increases genetic variability.

Mutations play a crucial role in evolution as they increase genetic variability, which is the basis for natural selection.
If a mutation confers a survival advantage, it may be positively selected for, leading to its prevalence in the population over generations.
Genetic drift can also influence the frequency of alleles in a population. It is a random fluctuation in allele frequencies, especially significant in small populations.