When multiple different alleles for a gene are present in a species's population it is called polymorphic. Most different alleles are functionally equivalent, however some alleles can give rise to different phenotypic traits. A gene's most common allele is called the wild type, and rare alleles are called mutants. The genetic variation in relative frequencies of different alleles in a population is due to both natural selection and genetic drift. The wild-type allele is not necessarily the ancestor of less common alleles, nor is it necessarily fitter.
একটি প্রজাতির জনসংখ্যায় যখন একটি জিনের জন্য একাধিক ভিন্ন অ্যালিল উপস্থিত থাকে তখন এটি কী বলা হয়?
polymorphic