Predator mediated selection and the impact of developmental stage on viability in wood frog tadpoles (Rana sylvatica)

Table 6 Comparison of path models.

		Maximum Likelihood Analyses
Model	Path constrained to zero	χ²	df	P	AIC	Δ_i	w _i	Evidence Ratio
1	Head length → Fitness	5.38	7	0.61	61.38	0	0.28
2	Max. swim speed → Fitness	1.98	5	0.85	61.98	0.60	0.21	1.35
3	Head ht. → Fitness	4.28	6	0.64	62.28	0.89	0.18	1.56
4	Tail muscle ht. → Max. swim speed	8.39	8	0.40	62.39	1.00	0.17	1.65
5	Tail fin ht. → Max. swim speed	1.58	4	0.81	63.58	2.19	0.09	3.00
6	Tail length → Max. swim speed	1.20	3	0.75	65.20	3.81	0.04	6.73
7	Tail muscle ht. → Fitness	0.89	2	0.64	66.89	5.51	0.02	15.70
8	Head ht. → Max. swim speed	0.36	1	0.55	68.36	6.98	0.01	32.77
9	Saturated model	--	0	--	70.00	8.62	0.00	74.33

Chi-square values (χ²), degrees of freedom (df), and the associated P value report the significance of the model. Note that model 9 is saturated, and thus the fit of the model to the data could not be tested using the chi-square statistic. In models that are not significant, the data are a good fit to the model. AIC = Akaike Information Criterion; Δ_I = difference in AIC scores between the best model and subsequent model; w_i = normalized relative likelihood of the model given the data; Evidence Ratio = the relative odds that a model is the best given the data.

ISSN: 2730-7182