Table 2.

Life-history traits and fitness components in outcrossed (between-family) and full-sibling matings in butterflies originating from the old isolated PT population and the large ÅL reference population and the corresponding estimates of inbreeding depression and genetic load

	ÅL					PT					PT vs. ÅL§
	Average trait value*		t test†		Inbreeding depression:‡	Average trait value*		t test†		Inbreeding depression:‡	t test		Genetic load:
Trait	Outcrossed	Sib- mated	t	P		Outcrossed	Sib- mated	t	P		t	P	LPT
Prezygotic
Timing of reproduction
Mating rate, /d, sqrt	1.900	1.650	1.93	0.06	0.13	1.237	1.239	−0.02	0.99	0.00	3.41	0.00	0.35
Oviposition rate, first egg clutch, /d, log	0.343	0.319	1.26	0.22	0.07	0.507	0.539	−0.16	0.87	−0.06	−1.75	0.09	−0.48
Oviposition rate, egg clutches/d, sqrt	0.161	0.138	1.13	0.27	0.14	0.228	0.194	0.89	0.38	0.15	−1.99	0.06	−0.42
Egg clutch size
Size of first egg clutch	241	201	1.69	0.10	0.17	148	153	−0.29	0.78	−0.03	4.65	0.00	0.39
Average size of all egg clutches	192	169	1.20	0.24	0.12	118	112	0.34	0.74	0.04	4.75	0.00	0.39
Postzygotic
Survival
Hatching rate of first egg clutch, %, asin	82	56	2.60	0.01	0.32	64	41	2.40	0.02	0.36	2.36	0.02	0.22
Average hatching rate of egg clutches, %, asin	73	53	2.05	0.05	0.28	46	28	1.85	0.08	0.39	4.81	0.00	0.37
Larval survival before diapause, %, asin	95	73	4.28	0.00	0.23	53	59	−0.21	0.83	−0.11	4.36	0.00	0.44
Development
Average embryo development time, /d	0.075	0.073	1.61	0.12	0.02	0.069	0.067	1.85	0.08	0.03	6.90	0.00	0.08
Average larval growth rate, /d	0.045	0.042	3.04	0.01	0.07	0.046	0.048	−0.61	0.55	−0.04	−0.48	0.64	−0.02
Average larval weight, mg	4.5	4.7	−0.56	0.58	−0.04	2.2	2.2	0.38	0.71	0.00	11.84	0.00	0.51
Reproductive fitness
Larval group size at diapause, sqrt	190	104	3.38	0.00	0.45	54	43	−0.13	0.90	0.20	5.35	0.00	0.72
Lifetime larval production, sqrt	443	284	1.97	0.06	0.36	139	103	1.30	0.21	0.26	4.13	0.00	0.69

The traits are divided into prezygotic and postzygotic. Transformations of variables: sqrt, square-root transformation; log, logarithmic transformation; asin, arcsine transformation.

*The average trait values are calculated from nontransformed data.

^†Average trait values for the cross types were tested with a t test (using transformed data if a transformation was used).

^‡Inbreeding depression coefficients , where and are the average values for sib-mated and outcrossed females.

^§The last three columns give a t test for the difference between the average trait values for outcrossed females from PT and ÅL, and , and the genetic load L for PT in comparison with ÅL ().