Degree
Relationship
2θ
jk
Δ
jk
1
Parent-offspring
1/2
0
1
Full sib
1/2
1/4
2
Grandparent-grandoffspring
1/4
0
2
Half sibs
1/4
0
2
Uncle-nephews
1/4
0
3
First cousins
1/8
0
Table 1:
P(IBD allele share) expected from the familial relationship.