What does a double horizontal line between a circle symbol and a square symbol as the only line directly connecting two individuals signify on a pedigree?

Question

Quizplus · Accepted Answer

A double line indicates consanguinity, or relationship by blood. It indicates a mating between two related family members. Brother and sister are connected by "sibship lines," and parents and children are indicated by lines of descent. A single horizontal line between a circle and a square indicates a mating but not marital status between the two.

What Does a Double Horizontal Line Between a Circle Symbol