Discontinuous variation – set number of differences (either yes or no) 

Limited number of differences with no intermediates between them, e.g. tongue rolling.

The path was discontinued so the fairy (discontinued variation)had to jump the gap to the next path with nothing between them. She would either make the jump (YES) or not make the jump (NO).

Examples

Discontinuous variation examples include the following:

The ability to roll your tongue, or not;

Your blood group