Table 2.

Model choice for colonization scenarios of Peponapis pruinosa into eastern North America based on the approximate Bayesian computation (ABC) analysis. Scenario 1 assumes a southerly range extension from Mexico through the east coast. Scenario 2 assumes the expansion passaged through the Great Plains (Midwest), then eastward to the Atlantic coast. Scenario 3 assumes that migrants from the east coast and the Midwest colonized northeastern North America. See figure 2 for details.

	Scenario 1	Scenario 2	Scenario 3
posterior probabilitya	0.043 [0.017–0.048]	0.643 [0.607–0.678]	0.325 [0.290–0.360]
confidence in scenario choiceb
type I error	0.201
type II error		0.105	0.283
number of outlying statisticsc
p < 0.05	4	3	6
p < 0.01	1	0	0
p < 0.001	0	0	0

^aThe median and 95% confidence intervals of the posterior probability indicate the revised probability distribution of each scenario after taking into consideration the prior information of the model.

^bModel performance of best scenario. Type I error indicates the probability with which the best model is rejected. Type II error indicates the probability of deciding for best scenario when it is not true.

^cThe number of summary statistics significantly different than the observed data. These statistics were used to discriminate between competing scenarios.