Table 2.

Statistics for the regression of the standardized contrasts of coloration on toxicity, under the punctuational and gradual models of evolutionary change, using observer- and computer-rated estimates of coloration

Model	Rating	Contrasts	Tandem	R2	F value	t value	P value
Punctuational	Observer	17	14	0.51	16.43	4.10	0.001
Gradual	Observer	17	13	0.38	9.83	3.14	0.006
Punctuational	Computer	17	15	0.83	78.89	8.88	0.000
Gradual	Computer	17	15	0.71	38.27	6.19	0.000

Tandem refers to the number of contrasts in which toxicity and coloration evolved in the same direction.