How does the computer know how to post DNA information?

Question

I'm looking at the profile for Robert Calvert, who at present is linked only to a daughter.  Yet there is DNA information posted on the right side to two persons named Calvert with respect to y-DNA, which can only be passed through the male line.  There is no male line linked on WikiTree at this moment.  

Can someone explain this?

Answer 1

Clayton Calvert Sr. and Robert Calvert are both descendants of John Calvert 

Donald Calvert and Robert Calvert are both descendants of John Calvert

Comments

And to answer your question about the computer knowing, Jack, Wikitree is programmed with the rules for Y-DNA inheritance, and it knows they share a common patrilineal ancestor. In other words, WT knows that if two people share a common male ancestor through the male parents, they will share some Y-DNA.

Answer 2

I think it's because Robert Calvert has male siblings with descendants that are in the same YDNA line.