In the late 1920s, a mutation occurred in many silver fox farms around the world. The fox farms that sold expensive furs were proud of the quality of their furs, and each advertised that it had the best and most pure breed of all the fox farms. The new mutations produced a "platinum" coat pattern that was commercially desirable, so the farms crossed them to get more. The results of their breeding experiments were as follows: (1) silver ´ silver ® all silver offspring; (2) silver ´ platinum ® equal numbers of silver and platinum; (3) platinum ´ platinum ® 2 platinum for each silver offspring. Explain.