Table 4 . Temporal differentiation of a subset of candidate genes.

	Geographic differentiationa		Temporal differentiationb
			All samples		Only North American samplesc
	nucleotide differentiationd		nucleotide differentiation		nucleotide differentiation		amino acid differentiatione
	Fst	P-value	Fst	P-value	Fst	P-value	Fst	P-value
Irbp	0.144	0.111	0.170	0.038	0.000	0.334	−0.010	0.455
krimp	0.143	0.004	0.011	0.262	−0.009	0.635	0.006	0.345
Hen1	0.632	<0.001	0.303	0.001	0.173	0.003	0.261	<0.001
Spn-E	0.459	<0.001	0.053	0.08	0.031	0.097	0.071	0.033
squ	0.028	0.25	0.202	0.001	0.071	0.036	0.039	0.103

All the significant results are in boldface type.

^aGenetic differentiation between current (post–P-element) African and North American populations.

^bGenetic differentiation between pre–P- and post–P-element invasion populations.

^cThe temporal differentiation was estimated considering only North American samples of both populations (before and after P-element invasions).

^dGenetic differentiation estimated using nucleotide sequences.

^eGenetic differentiation estimated using amino acid sequences.