Nessel Genealogy and Nessel Family History Information

Interesting how many Nessels a Google search turns up. My father, who was born in Zurich in 1895, was originally named Markus Nesselstrauss. When he came to America sometime before WW1 he shortened his name to Nessel. He was the only one of his siblings to have done this. Married twice, he sired four children, three with his first wife and one-- me-- with his second. Could all the Nessels in America be descended from my father? Surely not. So where did they come from?