Under these circumstances, there are more than two gene products affecting the same phenotype, and these products may have complex hierarchical relationships. Any time two different genes ...

The term "phenotype" refers to the observable physical properties of an organism; these include the organism's appearance, development, and behavior. An organism's phenotype is determined by its ...

For example, if a mutation led to brighter feather ... This would result in the bright feather phenotype being more likely to be passed on, meaning that over time there will be more bright ...