Evolution of Genes - Alleles

Alleles

Humans and most other multicellular creatures are diploid, meaning they carry two sets of virtually identical chromosomes (one inherited from the mother, one from the father). The two members of a chromosome pair (called homologous chromosomes) carry identical sets of genes, so that each Two common mechanisms of gene duplication. organism has two copies of each gene. A point mutation in one of these creates a new form of the gene. Different forms of the same gene are called alleles. Creation of alleles is one of the most common forms of gene evolution. The existence of diploidy allows a greater tolerance of new alleles, since a mutation to one allele still leaves the other one functioning, and in many cases this may be sufficient for survival. The existence of alleles allows greater genetic diversity in a population, which may increase that population's ability to adapt to changing environmental conditions.