Table 1. Number of generations to sympatric speciation under various strengths of disruptive selection for computer-simulated seahorse populations of two different sizes with either moderate (≈0.5) or low (≈0.3) heritability of size.

	Mean time to speciation				Proportion of runs resulting in speciation
	n = 200		n = 1,000		n = 200		n = 1,000
Fitness of intermediates	h2 = 0.34	h2 = 0.53	h2 = 0.32	h2 = 0.50	h2 = 0.34	h2 = 0.53	h2 = 0.32	h2 = 0.50
0.50	59.0	40.0	62.6	36.9	1.00	1.00	1.00	1.00
0.70	181.8	77.0	223.8	75.1	1.00	1.00	1.00	1.00
0.80	784.2	238.2	495.2	150.0	0.80	1.00	1.00	1.00
0.85	709.0	1,160.3	786.7	238.6	0.05	0.60	1.00	1.00
0.90	Never	Never	1,775.3	537.6	0	0	0.75	0.95
0.95	Never	Never	Never	Never	0	0	0	0

On the left we show the mean number of generations to speciation for those simulation runs in which speciation occurred. These results are based on 20 simulation runs for each parameter combination. An entry of “Never” indicates that speciation did not occur in any of the runs in ≤3,000 generations for a particular combination of parameters. In the columns on the right, we show the proportion of runs in which speciation did occur in ≤3,000 generations. In these simulations, individuals mated size-assortatively according to the preference function estimated from our empirical data on seahorse parentage.