Final answer:
Mutations in the gene associated with Huntington's disease introduce a new allele that affects the phenotype. This contributes to genetic variation in our species.
Step-by-step explanation:
Mutations in the gene associated with Huntington's disease:
Mutations in the gene associated with Huntington's disease contribute to genetic variation in our species by introducing a new allele that affects the phenotype. In the case of Huntington's disease, the mutated gene results in the production of a defective protein that causes nerve cell degeneration and eventually leads to the symptoms of the disease.
This mutation can occur spontaneously or be inherited from a parent who carries the mutated gene. These mutant genes can contribute to genetic variation in the human population because individuals with the mutated gene may pass it on to their offspring. While the disease itself is debilitating and often fatal, the mutated gene can remain in the population because it may not be expressed until an individual reaches middle age or later, allowing them to reproduce and pass on the gene.