Genetic relationship between Dead heads and Phish phans?

(via Sue w.): Are Deadheads Phish naturals? Fans explain appeal of 2 groups that are similar yet different (Charlotte Observer), features shocking new insights such as:

"I liked Phish because I liked the Dead," he added. "They do have the improvisational jamming in common, but I think the Dead had so much more soul. They had roots in Americana - blues, country and bluegrass."

and oh, but I can't go on.