Using the graphic of homologous structures, explain how homologous structures show common ancestry?

How do homologous and analogous structures provide evidence for evolution?Evidence for evolution is provided by homologous structures. These are structures shared by related organisms that were inherited from a common ancestor. Other evidence is provided by analogous structures. These are structures that unrelated organisms share because they evolved for the same function.

The ratio of purple flowers to white flowers would be 3:1.