Table A1. Effect of a single mutation at B, assuming that A is initially polymorphic.

	Gamete frequencies
Case	A1B1	A1B0	A0B1	A0B0	D
General	w	x	y	z	wz − xy
Before mutation	0	a	0	1 − a	0
A1-linked mutation	1/2N	a − 1/2N	0	1 − a	(1 − a)/2N
A0-linked mutation	0	a	1/2N	1 − a − 1/2N	− a/2N