The beaks of flocks x, y and z are shown. Flock x has a thin and pointy beak. Flock Y has a large and wide beak. Flock Z has a short and pointy beak.

The birds shown above have beaks with three different shapes and sizes. These genetic variations in the beak each appeared initially due to The beaks of flocks x, y and z are shown. Flock x has a thin and pointy beak. Flock Y has a large and wide beak. Flock Z has a short and pointy beak.

The birds shown above have beaks with three different shapes and sizes. These genetic variations in the beak each appeared initially due to The beaks of flocks x, y and z are shown. Flock x has a thin and pointy beak. Flock Y has a large and wide beak. Flock Z has a short and pointy beak.

The birds shown above have beaks with three different shapes and sizes. These genetic variations in the beak each appeared initially due to The beaks of flocks x, y and z are shown. Flock x has a thin and pointy beak. Flock Y has a large and wide beak. Flock Z has a short and pointy beak.