Evolutionary Divergence
Evolutionary Divergence is when one animal group slowly splits into two types that look and act very different.
Think of it this way
One batch of plain dough sits on the counter, split into two bowls. You add sugar and fruit to one, herbs and salt to the other. After many rounds of mixing, the two doughs look and taste nothing alike. That is how one group of animals can split and slowly change into two very different types.
Explaining evolutionary divergence by grade level
Arctic foxes have white fur and short ears to stay warm. Red foxes have brown fur and big ears to stay cool. Long ago, they shared the same family. Over time, each group changed to fit its own home.