Blue eyes are caused by a gene mutation. For years, researchers had searched for it on the OCA2 gene. The OCA2 gene determines how much brown pigment is in our eyes. But what they were looking for ...

Epistasis describes how gene interactions can affect phenotypes ... what is the ratio of blue offspring to nonblue offspring? The results of such a cross are detailed in Table 3.

In the poultry world, the “blue” gene is quite a remarkable phenomenon. This gene doesn’t necessarily lead to a bird with entirely blue feathers. Instead, it can spawn a spectrum of colors ...