Table 2.

Pairwise F_ST comparisons based on sum of squared size differences (R_ST) and effective number of migrants for U.S. and U.K. pony populations

	Welsh Sect. A	Welsh Sect. B	U.S. Welsh	Fell	U.S. Fell	High.	U.S. High.	Conn.	U.S. Conn.	Dart.	U.S. Dart.	Shet.	U.S. Shet.
Welsh Sect. A	1.87	15.84	44.76	9.2	1.765	2.6	3.045	4.09	8.47	3.02	3.315	4.745	7.41
Welsh Sect. B	0.016	1.96	12.01	10.58	1.655	2.36	2.02	8.13	11.215	6.775	5.31	5.355	6.29
U.S. Welsh	0.006	0.02	2.25	0.037	1.505	0.099	3.05	0.069	0.038	0.101	3.15	0.077	4.8
Fell	0.026	0.023	6.535	2.08	13.26	5.755	13.9	7.68	11.82	3.83	4.29	3.29	3.34
U.S. Fell	0.124	0.131	0.142	0.019	1.81	0.081	3.67	0.089	0.081	0.139	1.13	0.153	1.195
High.	0.088	0.096	2.28	0.042	2.825	1.92	20.07	4.74	3.865	3.42	1.49	1.37	1.19
U.S. High.	0.076	0.11	0.076	0.018	0.064	0.012	1.72	0.069	0.056	0.119	0.17	0.157	1.46
Conn.	0.058	0.03	3.375	0.032	2.565	0.05	3.395	2.12	105.32	10.64	1.7	3.71	2.515
U.S. Conn.	0.029	0.022	6.27	0.021	2.855	0.061	4.255	0.002	2.18	0.028	2.46	0.044	4.725
Dart.	0.076	0.036	7.235	0.061	1.55	0.068	1.85	0.023	8.565	1.85	2.44	3.17	2.16
U.S. Dart.	0.07	0.045	0.074	0.055	0.181	0.144	1.225	0.128	0.092	0.093	1.67	0.152	1.725
Shet.	0.05	0.045	3.005	0.071	1.39	0.155	1.345	0.063	5.485	0.073	1.4	1.74	14.28
U.S. Shet.	0.033	0.038	0.05	0.07	0.173	0.173	0.146	0.09	0.05	0.104	0.127	0.017	1.68

Below diagonal: Pairwise F_ST based on sum of squared size differences (R_ST). Above diagonal: effective number of migrants (Nm) per generation, based on Slatkin, 1995. Diagonal elements: Theta H estimates 4N_eμ = (1/(1−H_e)²)−1. Abbreviated populations are defined as follows: Welsh Section A, Welsh Sect. A; Welsh Section B, Welsh Sect. B; U.S. Welsh Pony, U.S. Welsh U.S.; Highland, High.; U.S. Highland, U.S. High.; Connemara, Conn.; U.S. Connemara, U.S. Conn.; Dartmoor, Dart.; U.S. Dartmoor, U.S. Dart.; Shetland, Shet.; U.S. Shetland, U.S. Shet. All values are significantly different (P < 0.05) with the exception of those in cells shaded grey.