Genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a protein, which cause different phenotype traits. Colloquial usage of the term "having a gene" (e.g., "good genes," "hair colour gene") typically refers to <answer>having a different allele of the gene</answer>. Genes evolve due to natural selection or survival of the fittest of the alleles.
What does "having a gene" or a "good gene" typically refer to?
having a different allele of the gene