How do mutations contribute to genetic variation in a population?

Mutations contribute to genetic variation by introducing new genetic material into a population's gene pool.

Mutations are changes in an organism's DNA sequence. They are the primary source of genetic variation, which is the raw material for evolution. Without genetic variation, a population cannot evolve in response to changing environmental variables and may face an increased risk of extinction.

Mutations can occur in several ways. They can be caused by errors during DNA replication, by exposure to radiation or chemicals, or by viruses. Some mutations affect only a single DNA base pair, while others can change large segments of a chromosome. Mutations can occur in any cell of an organism, but only mutations in reproductive cells (sperm or eggs) can be passed on to offspring and contribute to genetic variation in a population.

The effects of mutations on an organism can vary widely. Some mutations have no noticeable effect, while others can have significant impacts on an organism's phenotype (observable traits). Beneficial mutations can increase an organism's fitness, or ability to survive and reproduce. For example, a mutation might confer resistance to a particular disease or allow an organism to better exploit a particular resource. Over time, beneficial mutations tend to increase in frequency in a population through the process of natural selection.

On the other hand, harmful mutations can decrease an organism's fitness. For example, a mutation might cause a genetic disorder or increase an organism's susceptibility to a particular disease. Harmful mutations tend to decrease in frequency in a population over time, but they can persist if they are recessive (only expressed when an individual has two copies of the mutation) or if they confer some advantage in certain environments.

In summary, mutations are a crucial source of genetic variation in populations. They introduce new genetic material into a population's gene pool, providing the raw material for evolution. The effects of mutations can vary widely, but over time, natural selection tends to increase the frequency of beneficial mutations and decrease the frequency of harmful mutations.